1 THE PACKAGING OF HIGH-PERFORMANCE ......Concrete-Cement Industry. The research activities of the Department were conducted in collaboration with external researchers and specialists

1

Primo report su ricerca DRY e altri additivi/aggiuntivi – 20 gennaio 2012 – Bozza interna di Paolo – Check Mat +Ric+Ma

THE PACKAGING OF HIGH-PERFORMANCE CONCRETE WITH CONTROLLED VOLUMETRIC STABILITY:

SYNERGISTIC ACTIONS OF MICRO-EXPANSIVE/COMPACTING ADDITIVES AND ADDED FINE MINERALS WITH POZZOLANIC ACTIVITY (FOR THE PREFABRICATION INDUSTRY AND THE C.A.P.)

ABSTRACT: A RESEARCH PROJECT AT THE DEPARTMENT OF EARTH SCIENCES IN COLLABORATION WITH OTHER PARTNERING LABORATORIES ON THE THEME OF THE COMBINED ACTION OF DISTINCT ADDITIVES WITH MICRO-EXPANSIVE AND COMPACTING ACTION, AS WELL AS FINE POWDERS WITH POZZOLANIC ACTIVITY AND FILLERS WITH SUPER-PLASTICIZING ACTION FOR THE PACKAGING OF HIGH PERFORMANCE, STRUCTURAL CONCRETE (HAVING MECHANICAL PROPERTIES AND DURABILITY), AT CONTROLLED VOLUMETRIC STABILITY WITH MODULATED INITIAL MICRO-EXPANSION. THE RESEARCH PROJECT CONCENTRATED ON MAINTAINING LOW COSTS FOR A GREATER COMPETITIVENESS IN THE PREFABRICATION INDUSTRY AND THE C.A.P. THE CEMENT UTILIZED IN THE FIRST PHASE OF THE RESEARCH WAS CEM I 52,5 R, AND WITHIN THE FOLLOWING MONTHS THE PRESENTATION OF THE RESULTS OF THE RESEARCH FOR THE PACKAGING OF CLS WITH CEM II 42,5 R WILL BE PROVIDED.

M. de Gennaro (*), P. Cappelletti (*), M. D’Amore (*), M. Felitti (**), P. Marone (**) F. Gagliardini (**)

(*) FACULTY AND RESEARCHERS OF THE DEPARTMENT OF EARTH SCIENCES(**) PROFESSIONAL CONSULTANTS OF ISIM AND CHEMICAL CONSTRUCTION

REV. 6: DATE- JULY 2012. REV. 0-1-2: DATE- JANUARY 26, 2012

1


Introduction

In the year 2011, the Chimica Edile Company stipulated an agreement with the Department of Earth Sciences, University of Naples Federico II for the implementation of a technical-scientific research project. The objectives consisted in the study of micro-expansive action additives in the sector of the Concrete-Cement Industry. The research activities of the Department were conducted in collaboration with external researchers and specialists (D’Amore, Felitti, Marone, Alfano, Gagliardini, etc.).

The primary objective of the research is the specific study of a line of additives with micro-expansive properties produced by Chimica Edile to verify the action in the setting and hardening phases of concrete.

Throughout the course of the research, the possibility of using this additive in a mixture with other materials with pozzolanic activity was also experimented.

These considerations were emphasized in order to manufacture concrete possessing essential performance characteristics (“high performance” according to project requirements), while maintaining competitive, low costs (the technical-economic performance concept of the research project involves creating a modern, innovative and competitive concrete, with an elevated chemical-mechanical resistance and controlled volumetric stability).

The research project recently extended the collaboration to involve other technology specialists, producers and private businesses in the sector in order to reach additional scientific and field-related findings. This report describes and discusses the first results of the research in relation to its initial stages. Moreover, it will be subject to updating and follow-up in order to (1) expand the range of tests and (2) further optimize the performance of the "MIX DESIGN of the concrete lined steel (cls) to achieve controlled volumetric stability at a high performance level”.

Materials

The additives and additional active minerals studied and utilized to achieve the Mix Design Optimization were as follows:

a) A rapid and immediate micro-expansive/compacting additive (in powder form) DRY D1® Rapido (UNI EN 206, UNI EN 196-2, UNI EN 196-3,UNI 196-6, UNI EN 197-1, UNI 8146, UNI 8147, UNI 8148, UNI 6555, UNI 7086), an addition consisting in a dual action, non-metallic oxide with: (1) immediate and brief “initial” micro-expansive action (1 ora÷48 ore) and (2) a subsequent compacting action that increases compression resistance “fck/Rck.1 day” e “fck/Rck.3 days”. This occurs in short time intervals, thereby decreasing the porosity of the fresh/plastic concrete (self-compressing -> self-compacting). This product is derived by using special cooking processes of granules of calcium carbonate in ovens at particular temperatures; it is entirely free of chlorides, and obtained by means of micronization and screening processes. It was used with a dosage of less than 1% of the cement (note: a dosage of ~1% is defined as “low” when compared to a dosage of approximately 4÷8% used in other research projects (see Bibliographical notes)).

b) A Broad spectrum, anti-shrinking, compacting Additive with the added property of an acting accelerant of pozzolanic activity, (in powder form) DRY D1® Normale (UNI EN 206, UNI EN 196-2, UNI EN 196-3, UNI 196-6, UNI EN 197-1, UNI 8146, UNI 8147, UNI 8148, UNI 6555, UNI 7086). It is characterized by the addition of a non-metallic oxide of modulated micro-expansive action; it serves to counteract the hygrometric shrinking of the first seven days (approximately). Other actions include a significant increase in compression resistance (“fck/Rck. 3 days” and “fck/Rck. 14 days”), a decrease in the porosity of concrete lined steel during the first hardening phase (self-compressing>self-compacting), prevention of the phenomena of shrinkage-cracking and a significant reduction in autogenous shrinkage (see in the bibliographical notes – Argos – Tests of the expansion/shrinkage of cement pastes, Colombia). The presence of additives with pozzolanic

1


activity favors and accelerates the pozzolanic activity within 28 days. This additive is derived from limestone extracts from the Argentine Andes and involves special cooking processes for prolonged times at a high temperature. The additive was utilized in the present research with a dosage, also in this situation, definable as “low” (approximately 1%).

c) A Slow reaction , anti-shrinkage Additive (in powder form) DRY D1® Lento (UNI EN 206, UNI EN 196-2, UNI EN 196-3, UNI 196-6, UNI EN 197-1, UNI 8146, UNI 8147, UNI 8148, UNI 6555, UNI 7086). This is a non-metallic oxide with micro-expansive action, which serves to counteract the hygrometric shrinking over prolonged times (up to 28 days). It eventually, significantly reduces the coefficient of the viscosity of the loaded down, hardened concrete (the research is in the development and verification phase). This additive is derived from special cooking processes for prolonged times at a high temperature. The process involves select granules of limestone extracts from the Argentine Andes with additions of siliceous materials such as active adjuvants, which are free from chlorides, and subject to processes of mixing, grinding and sifting in order to obtain an optimal granulometric curve and low reactivity. It was utilized in the second phase of the present research with a “low” dosage, close to 1÷1.4% of the cement (note: this is a new generation additive specially formulated by Chimica Edile in 2011 for the research project, and it is currently produced at the company facilities).

d) The addition of other materials with pozzolanic activity such as fly ash, metakaolin, silica fume and ground volcanic tuffs; whereas, the “Fly Ash” utilized in the project came from centers for the production of electric energy from fossil fuels (UNI EN 206, UNI EN 450/2005). As noted in the bibliography, these additives have “pozzolanic” action (favoring the ulterior formation of C-S-H) “fillers” because of the dimensions of the spherical particles (1÷200 μm). Utilized in the second phase of the project, the dosage was equal to 33% of the cement and approximately 10-12% of the sand. The principal beneficial effects of the pozzolanic behavior were recorded from the twentieth to the ninetieth day after the date of the casting (pozzolanic activity index, UNI EN 196-1, EN 450-1). The combined presence of these additions together with some micro-expansive agents potentiated the "filler" effect. Until now, they seem to have substantially accelerated the index of pozzolanic activity of the fly ash before 28 days, resulting in a significant increase of the mechanical resistance and the control of most of the phenomena of shrinkage / viscosity that characterize the concrete, rich in fine particles and SCC. The research was validated by applications not only in a laboratory, but in industrial situations, as well.

e) Super-plasticization Additive (UNI EN 206, UNI EN 934-2) made from water-soluble polymers with a traditional dosage of about 1% of the weight of the cement (equivalent) and having efficiency and proven compatibility with respect to the MIX DESIGN as a whole and in respect to the individual components illustrated in the following points.

f) A hardening accelerant Additive (UNI EN 206, etc.) used in cold climates (temperatures below 10÷8°C). It was utilized with a dosage significantly superior to 1% and in any case, in function with the outside temperature and the minimal number of hours assigned for the removal of formwork (for example for an Rck>30 MPa at 16 hours). The accelerating additive was tested to preserve and secure, even in winter, the performance standards of the MIX DESIGN (Rck) in the 12 to 24 hours required for precast concrete in the sector of prefabrication.

The super-plasticizing additive (“sf”) point a), and the accelerating admixture (“HBE”), points f) have a fluid-based consistency, and according to their formulations may significantly vary the effectiveness and performance of the other additives as demonstrated and detailed in the state of the art research of additives based on polymers for concrete. The other inorganic additives, points a), b), c) and d), to be mixed in the paste, all have the consistency of a “fine” dry powder, (generally from 1 micron to 500 microns) insoluble and / or packable in water-soluble /airtight and/or steam packaging. It is believed that for the first time their specific “synergistic combination” was studied and refined, and that for one of the compositions (DRY D1 Slow) - its particular formulation and production.

Regarding the definition of added elements and/or additives in relation to the standard regulations in force, it would be legitimate to define a fluid or powder material as an additive, in the case of its addition

1


in relatively minimal quantities: eg. close to 1% of the cement. However, one would consider added elements as being additions in percentages far greater than 1% of the cement. The 3 products described with an expansive function (DRY D1® Quick , DRY D1® Normal, DRY D1® Slow and the pozzolanic additions, points a), b), c) e d)) may be packaged and added individually, as a mix of expansive agents and/or as a unique formulated blend.

The additives/added elements used in the research are easily available on the market, in particular, those classified as “micro-expansive/anti-shrinkage and compacting” (the DRY D1® Line of products), which were made available and reformulated ad hoc for the research by the CHIMICA EDILE group. The other additives utilized, points a) and f) with a base of polymers and plasticizing substances, are produced and marketed by different primary leaders in the sector. “ENEL/General Admixture” generously supplied the fly ash.

Work phases, research sectors, timing and results

A reliable research program requires long implementation times and meticulous follow up, (several years) as it addresses and develops broad, articulate themes. This research requires the execution and monitoring of tests on a long-term basis, up to 90 days in a laboratory, with subsequent optimization in the formulations and dosages of the additives/added elements of the various Mix Designs of the concrete with thorough repetitions in the various testing and monitoring campaigns, both in the laboratory and on an industrial level. The general research program divided the research into distinct timeframes, and then subdivided the research into specific sectors of interest for the market and technicians.

SECTOR 1: PREFABRICATION OF STRUCTURAL ELEMENTS (June 2011-July 2012) The initial materials and tests performed were as follows: Cement dosed concrete 52, 5 R Type I and resistance f.ck.cube > 30÷35 MPa after 1 day and f.ck.cube> 70÷80 MPa after 28 days (EN12390). They indicated low water absorption for immersion (UNI 7699/UNI EN 13755), shrinkage close to “zero”, and if requested < 50 μm after 28 days (Expansion/shrinkage Test counteracted according to UNI 8148 type “B” ). Results indicated high performance of durability and resistance to water washout as a function of the environmental characteristics and the class of the structure (class 2 > 100 years, UNI EN 206–2006 and UNI 11104-2004). The workability/consistency index of at least “S 4”, and the final “economic” competitiveness (analysis of the appropriateness of the cost of materials) were also analyzed.

NOTE: The research was predominantly oriented in the world of the prefabrication of structural elements, of structurally performing concrete and of the c.a.p. The concrete was dosed with 52, 5 R Type I cements. The performed tests provided for the determination of the following: the f.ck.cube after 1 and 28 days, the water absorption for immersion (UNI 7699/UNI EN 13755), the counteracted expansion/shrinking according to UNI 8148 type “B” and the ultrasonic velocity. Other considerations included resistance to water washout as a function of the environmental characteristics and the class of the structure, the workability/consistency index and the analysis of the adequacy of the cost of materials.

1


SECTOR 2: Concrete at controlled volumetric stability for industrial pavements. (May 2012-October 2012)NOTE: Technology oriented research for industrial flooring.

CONTINUOUS INDUSTRIAL FLOORING IN THE ABSENCE OF SEALS

1


SECTOR 3: CONCRETE (July 2012-June 2013)FIELD OF RESEARCH: Concrete dosed with 42, 5 R and N e 32, 5 R and N cements.

NOTE: The research was essentially oriented in the sector of the prefabrication of structural elements and of the c.a.p. >C45/55 - D16 - S4 – XA3/XC4– WASHOUT RESISTANCE – SHRINKAGE close to “0”

CONCRETE BATCHING PLANTS

SECTOR 4: Distinctly expansive pozzolanic concrete for use in land and rocks. NOTE: the research will be oriented towards geotechnical engineering and for the geo-compacting of the land in contact with foundation poles, root poles, micro-poles, tie-rods, anchors, underpinnings, etc., where advantageous phenomena of significant concrete expansion is admissible.

SECTOR 5: Industrial and pozzolanic mortar utilized for restoration.

SECTOR 6: Light, structural concrete.

1


SECTOR 1 – THE PREFABRICATION OF STRUCTURAL ELEMENTS

General considerations regarding the Mix Design of Concrete

The MIX DESIGN of the concrete developed (MD.cls) for sector 1, enabled a study regarding the optimization of the technical and economical performance. The composition of the cls is made up of the combination of constitutive elements based on the following schematic and classical formulation:

MD.cls = (“c” + “a” + “i”) + (“sf”) + (“e.r” + “e.n” + “e.L”) + (“cv” / “rmv”) + (“heb”)

Whereas:

“c” = cement (Portland)

“c.eq” = cement equivalent (Portland cement + k.1 x minerals with pozzolanic activity = c + k.1 cv)

“a” = effective water of mixture

“i” = aggregates (large, medium, fine)

i.eq = aggregate material equivalent (inert materials+ (1-k.1) x phases of pozzolanic activity)

i.TOT = total aggregate materials (inert materials + phases of pozzolanic activity)

“sf” = super-plasticizing additive (different types such as modified ether- based polystearici/ polycarboxylic, poli-acrilato/poli-etere, etc.)

“e.r” = agent DRY D1 ® Rapid compacting and micro-expansive additive with quick and immediate action (2 hours ÷ 48 hours).

“e.n” = agent DRY D1 ® Broad spectrum, mid-term action, normal compacting and micro-expansive reducer of hygrometric/chemical shrinkage (after approximately 1 week), with an accelerating function of pozzolanic activity in the case of added elements “with pozzolanic activity”.

“e.L” = agent DRY D1 ® Lento Slow action, prolonged term, compacting, micro-expansive and reducer of hygrometric shrinkage (after 28 days).

“cv” = Fly ash with pozzolanic and “filler” activities.

“rmv” = residues of the milling of zeolithized volcanic rocks with pozzolanic activity.

“heb” = an eventual accelerant in cold climates (<8÷10°C) and rapid castings (less than 12÷24 hours)

1


Considerations regarding the Mix Design of the basic c ement pastes Taking into account the difficulties involved in the analysis of concrete in respect to the complexity of

the mixture containing predominant percentages of aggregates, it was considered opportune to begin by analyzing the individual components (Table 1) and subsequently, by analyzing the reaction products of simple mixtures of cement pastes (Table 2).

In order to verify the mineralogical composition of the raw materials and mixtures, researchers performed qualitative X-ray diffraction analyses of the powders of the samples packaged.

The preparation of the samples provided for both the “dry” micronization, to avoid the loss of soluble phases, and the micronization in deionized water. The latter procedure was performed using a Mc Crone apparatus with cylinders of Agate for 15 minute times, to obtain a particle size <5μm. This condition, as reported in literature (Bish and Chipera, 1988; Klug and Alexander, 1974), allows one to overcome many problems in the acquisition phase of the RX spectra (particle statistics, primary extinction, micro-absorption and above all, phases of the feldspathic type and phenomena of preferential orientation).

The powders thus obtained were analyzed using an automatic diffractometer, PANalytical X'Pert PRO PW 3040/60 (CuKα radiation, 40kV, 40mA) with an X’Cerlerator RTMS detector, managed by a PC using the PANalytical X'Pert program. All components were individually characterized in order to note their mineralogical composition (Table 1).

Table 1: Mineralogical phases identified in the individual components of the mix design of the cls. COMPONENT MINERALOGICAL PHASE OBSERVATIONSCement I 52,5 R Tricalcium silicate (Hatrurite), Brownmillerite,

Gypsum.Sand Dolomite With traces of quartzRice husk DolomiteDebris DolomiteDRY D1 RAPIDO Lime, Hatrurite, Portlandite, PericlasioDRY D1 NORMALE Lime, Hatrurite, PortlanditeDRY D1 LENTO Lime, Hatrurite, Portlandite With traces of amorphousFLY ASH Quartz, Mullite

CEMENT PASTES were then prepared with the following compositions: MD. paste = (“c” + “a”) + (“sf”) + “active component”

Whereas:

“c” = cement

“a” = effective water of the mixture

“sf” = super-plasticizer additive

“active component”= the individual additive a/o the individual added element a/o a combination of the active components representing the object of specific analysis.

The Mix Design related to the diverse CEMENT PASTES is reported in Table 2.

1


Table 2: Concrete MIX DESIGN

MIXConcrete

CONCRETE

[Kg/m3]

WATER[Kg/m3]

A/CSUPERPLASTICIZER

[Kg/m3]DRY

[Kg/m3]CV

[Kg/m3]RMV

[Kg/m3]HEB

[Kg/m3]

Cement paste 0

AS IS320 128 0.4 1.6

Cement paste 1

AS IS+DRY320 128 0.4 1.6 7

Cement paste 2

AS IS+CV320 128 0.4 1.6 100

Cement paste 3

AS IS+DRY+CV320 128 0.4 1.6 7 100

Table 3 indicates the results of the analyses XRPD carried out subsequently to the hardening of the mixtures in Table 2.

Table 3: Mineral phases in CEMENT PASTE.MIX

BASIC PASTEMINERALOGICAL PHASES

Cement paste 0AS IS

Portlandite, Ettringite, Hatrurite, Brownmillerite, Amorphous.

Cement paste 1AS IS+DRY

Portlandite, Ettringite, Hatrurite, Brownmillerite, Amorphous.

Cement paste 2AS IS +CV

Portlandite., Ettringite, Hatrurite, Brownmillerite, Quartz, Mullite, Amorphous.

Cement paste 3AS IS+DRY+CV

Portlandite, Ettringite, Hatrurite, Brownmillerite, Quartz, Mullite, Amorphous.

Figures 1, 2, and 3 report electron microscopy micrographs (SEM) of fragments of the samples taken of the various CEMENT PASTE MIXES.

1


Figures 1.a and 1.b: Comparative SEM micrographs (Magnification x200): Mix of the Basic Paste “As Is” (0) on the left and the Mix of the cement Paste “As Is + DRY D1 R/N al 2,2 %” on the right (1). The matrix of the second Mix, the same in terms of crystalline phases identified (table 3), is present with a greater quantity of cement gels and is significantly more compact.

1


Figures 2.a and 2.b: Comparative micrographs to the SEM (magnification x1500) of the Mix of the cement Pastes: “As Is” (0) on the left and “As Is + DRY D1 R/N 2, 2 %” on the right (1) after the flattening. The difference of the matrix between the two masses is evident, the first appears more discontinuous and porous, the second more continuous and closed. Other differences are also noticeable between the systems of fractures created by the crushing, in the first case, they are more diffused and articulated

Among the more porous zones, in the second MIX, they are more localized.

1


Figure 3: SEM micrograph (magnification x1500) of the Basic Paste Mix “As Is + DRY D1 R/N 2, 2 % +CV 30%” (3). The paste / cementitious matrix completely wraps around the microspheres of the fly ash and is compact (continuous mass of the gel). The system of fracturing of the material is further evident after the crushing test in which the fractures are localized.

The test of compression resistance by crushing, performed on the samples of cement pastes of dimensions 10x10x10 cm (UNI12390-3), revealed values ranging from 53.1 MPa (cement paste 0ASIS) and 58.8 MPa (cement paste + 3 AS IS DRY + HP), or about 10% more resistance after 28 days.

1


Considerations specific to the Mix Design of concrete cement

The active components were studied, verifying their combined action in the CONCRETE MIX, comparing, wherever possible, the results obtained with those in the literature and in the latest state of the art research on concrete:

TABLE 5.I: CONCRETE MIX DESIGN Phase 1MIX DESIGN

CLSCEM

[Kg/m3]H2O/c

[Kg/m3]SF

[Kg/m3]DRY R-N-L

CV[Kg/m3]

SAND[Kg/m3]

RICE[Kg/m3]

DEBRIS[Kg/m3]

HEB[Kg/m3]

MD.1 – AS IS 410 0.38 4.1 7 X X XMD.CLS 2 410 0.38 4.1 7 X X XMD.CLS 3 380 0.38 3.8 7 X X XMD.CLS 4 350 0.40 3.5 7 X X XMD.CLS 5 320 0.42 3.2 7 X X XMD.CLS 6 290 0.44 3.2 7 X X X

Others

TABLE 5.II: CONCRETE MIX DESIGN Phase 2

MIX DESIGN CLS

CEM[Kg/m3]

H2O[Kg/m3]

SF[Kg/m3]

DRY R-N-

L

CV[Kg/m3]

SAND[Kg/m3]

RICE[Kg/m3]

DEBRIS[Kg/m3]

HEB[Kg/m3]

MD.0 – AS IS 320 135 2.7-3.2 1145 550 350MD.CLS A1 320 135 2.7-3.2 7 1145 550 350MD.CLS A2 320 151 2.7-3.2 100 1045 550 350MD.CLS A3 320 151 2.7-3.2 7 100 1045 550 350

Others 290÷410

Slump tests were performed for the fresh mixes; for the specimens after 24 hours and after 28 days of density, non-destructive ultrasonic investigations, crush tests, SEM micrographs, fine sections under a polarized microscope, x-ray analyses, measurements of porosity, shrinkage-expanding tests, water absorption at atmospheric pressure and flexural tests were performed, as well.

Cement (c)

Binder: Portland Cement Class I 52, 5 R

As illustrated, the BASIC MIXES of CEMENT PASTE class I 52,5 R, water and plasticizing, were studied, subsequently adding, the expansive/anti-shrinkage/compacting agents and the added elements of pozzolanic minerals both alone and in combination with different doses of the other additions.

The f irst research phase (June 2011-October 2011) Specific CONCRETE MIX DESIGNS were studied and monitored, (“AS IS PASTES WITH SUPER-PLASTICIZING ADDITIVES” and WITH EXPANSIVE AGENTS DRY D1 type Rapido and type Normale, before the generation of micro-expansive additives) using varying dosages of Portland Cement I 52,5 R UNI EN 197-1 and UNI EN 11104 from 290 kg/m3 to 410 kg/m3 with incremental steps of 30 kg/m3 and with a constant dosage of the two expansive agents (approximately 0,8÷1,2% of the cement for each typology):

Cem Dosages: 290->320->350->380->410 kg/m3

1


The first phase of the research made it possible to deduce and validate that the optimal concrete from the technical and economic perspective (cost-benefit analysis) was the concrete with a dosage of 350 kg/m3 (note: this was initially packaged in total absence of pozzolanic charges and of slow expansive/anti-shrinkage/compacting of the latest generation. There was however, the presence of expansive additives of short and mid-term action, currently produced by Chimica Edile: DRY D1 Rapido e DRY D1 Normale). It is noted that from the perspective of the continual control of volumetric stability, the first generation expansive agents of Chimica Edile and other companies in the sector externalize their action in the first week! Some oxide-based additives on the market even terminate their action in the first week and in a few days, when in the presence of high temperatures. The cost-benefit analysis of the estimated costs of the MIXES’ raw materials indicated that MIX 1 (AS IS with 410 kg/m3 of CEM I 52, 5 R) is approximately equal to, or considerably higher in cost, compared to the cost of MIX 4 (with 350 kg/m3 of cement CEM I 52, 5 R and DRY D1 Quick and Normal additives, equal to about 1% +1% or 3.5 kg + 3.5 kg = 7 kg/m3). Nevertheless, MIX 4 has similar mechanical performances with respect to MIX 1, but offers the advantage of controlled volumetric stability (shrinkage near 200 microns m / m or 50-micron m / m of the initial expansion in the first 2 days and subsequent shrinkage after 28 days). For the purposes of the display classes (UNI 11104 and NTC-Technical Standards for Construction), the dosage of the cement equivalent of MIX 4 (350 kg of Portland CEM I 52.5 R) assumed, exceeds the minimum amount required by the regulations for XA2 / chemical attachment, XD2/cloruri, XF2-XF3/freeze-thaw, XC4/carbonatazione.

Note: (1) (2) (2) (2) (2) (3) (3)X0 XC1 XC2 XC3 XC4 XS1 XS2 XS3

Max rep.“a/c” 0,60 0,60 0,55 0,50 0,50 0,45 0,45Min Resistance MPa C12/15 C25/30 C25/30 C28/35 C32/40 C32/40 C35/45 C35/45Min Cement Kg/m3 300 300 320 340 340 360 360Min Air Cont. %OtherNote: (4) (4) (4) (5) (5) (5) (5)

XD1 XD2 XD3 XF1 XF2 XF3 XF4Max rep.“a/c” 0.55 0.50 0.45 0.55 0.50 0.50 0.45Min Resistance MPa C28/35 C32/40 C35/45 C32/40 C25/30 C25/30 C28/35Min Cement Kg/m3 320 340 360 320 340 340 360Min Air Cont. % 3 3 3Other

Note: (6) (6) (6)XA1 XA2 XA3

Max rep.“a/c” 0.55 0.50 0.45Min Resistance MPa C28/35 C32/40 C35/45Min Cement Kg/m3 320 340 360Min Air Cont. %Other Cem resistant to sulfates

TABLE UNI 11104 – (2): carbonatazione – (4): cloruri - (5): freeze-thaw - (6): chemical attachment

Results of the first phase of the project compared to the resistance characteristics of crushing cubes 15x15x15 cm.

1


The use of the micro-expansive and compacting agents led to an increase in compression resistance of between 10÷15%

15x15X15 cm CUBES AFTER THE CRUSHING WITH AND WITHOUT ADDED ELEMENTS/ADDITIVIES

The second phase of research (November 2011 – June 2012) The second phase of the research, benefitting from the state of the art knowledge and the results, that is to say, the summaries of the advantages and limitations of modern expansive agents, was characterized by the formulation of new MIX DESIGNS and by the production of new expansive agents “synergistically” combined with pozzolanic added elements and fillers. The analyses by microscope allowed the observation that the expansive agent, with a compacting function, emphasized the “filler” capability (filling) of the fine sands and above all of the spherical micro-sands (φ < 200 μm) more likely to move during the expansion/compacting processes. It should also be noted and further emphasized that the formation of an additional, small percentage of "expanded Portlandite derived from lime oxide" not only acts as another "alkaline reserve", in addition to the noted "Portlandite derived from the concrete" (see alite and belite ) and adequate "water molecules", but it also offers the beneficial addition of materials with pozzolanic activity to capitalize on this obvious potential.

Another positive side effect (significant) involves the compacting effect for auto-compression (self- compressing) and the increase in the contacts (wall effect) of the expansive agents that push and press the masses of the cement conglomerate (concrete). The expansionary effect, if properly modulated, leads to a decrease in the porosity of the concrete (with improvements of the critical aspects of the transition zone), the bleeding phenomenon, and internal discontinuity in the concrete setting

and hardening phase. These elements consequently enhance the triggering of pozzolanic reactions between the residual water, the Portlandite (from cement and the expansive agent) and the micro-silicon

Photo of the counter face of the fine

1


(silicon reactive dioxide) materials of the pozzolanic materials (especially in the first 28 days where the concrete still contains sufficient residual water), assisting the primary pozzolanic C-S-H processes. Therefore, the expansive additive may not only be formulated to contrast the shrinkage, but also to favor the pozzolanic activity of the fly ash and in general, of the pozzolanic materials in contact with the available Portlandite.

In philological dialectics, and taking into account the formerly summarized observations, the new mix designs have been studied and monitored with different combinations of additives, micro-expansive agents and active pozzolanic minerals in cement pastes (MD. paste), in specific environmental conditions (temperature, humidity, formwork). It was therefore necessary to come to an agreement with CHIMICA EDILE to formulate and test new expansive agents with slower, more modulated action (DRY D1 Lento). These agents would be used in conjunction with the other line of expansive agents in production (DRY D1 Rapido and DRY D1 Normale) to more effectively control the “micro-expansive phase” of the new concrete. Also considered, was the “complex evolution of its contraction phases”, (hygrometric shrinkage, autogenous shrinkage, thermal shrinkage for temperature reduction, viscous deformation based on compression/traction, etc.) in conjunction with the experience acquired from the expansive agents (“Rapido” and “Normale”).

In the second research phase, the new CLS MIX, which had resulted as “optimal” for the prefabrication industry, consisted in a dosage of 320 kg/m3 of Portland Cement I 52, 5 R. It also had an “a/c” ranging from 0,40÷0,45 more than the addition from 25 to 100 kg/m3 of materials with pozzolanic activity (Ground Volcanic Rock a/o Fly Ash a/o Silica Fume a/o Metacaolino). This served to obtain a total dosage of “equivalent cements” close to or greater than 330÷350 kg/m3 (“equivalent performance concrete” UNI EN 206 par. 5.2.5.3) with super-plastifying additives (~1%) and rapid action micro-expansive agents (~0,6% DRY D1 Rapido), both with normal (~0,6% DRY D1 Normale) and slow, prolonged action (~1÷1,2 % DRY D1 Lento). The cements included integrative and balanced expansive agents in respect to the complex phenomena of shrinkage/expansion listed.

For the purposes of the exposition classes (UNI 11104 and NTC-Technical Standards for Construction), the dosage of the cement equivalent of the FINAL MIX / IDEAL utilized, (320 kg and 100 kg of Portland Cem fly ash in addition to Portland cement) exceeds the minimum levels required by the regulations for XA2/ chemical attachment (353> = 320 C.Min), XD2/cloruri (353> = 340 c.mim), XF2-XF3/freeze-thaw (353> = 340 C.Min) XC4/carbonatazione (c = 320 + 0.33 x 100 = 353> 340 kg/m3).

38

56

70

1


Water

In respect to the UNI EN 1008, the “w/c” relationship was on an average equal to 0.40÷0.45, and in any case, also occurred with variable parameters between 0.375 and 0.45 (UNI EN 206-1 e UNI 8981-2). The experimental points (graphs of the Rck and tables of consistency/slump) are plotted on the graph in function with different “w/c” for the optimal MIX DESIGN (MIX n° A4) and indicate appropriate tolerance levels (note: the study may influence errors in water dosage of average “w/c”= 0.41÷0.42 in reference to the variability of both the Rck of hardened cls and the workability/slump of the fresh cls). Further additions of water were calculated in respect to the same dosage “w/c”, (0.41÷0.42) but reduced by a coefficient K equal to 0.40 for the fly ash (see UNI) and for the milled volcanic rock (note: the latter being very “water hungry” and with a “thermal zeolite” effect in function of the water absorption). The pragmatic criteria to determine the best water dosage adhered to State of the Art technology and the science of concrete (Abrams, Bolomey, Collepardi, Fuller, Lyse, etc.). The many parameters of the MIX (aggregate dosages and sizes) were significantly and expertly varied for the purpose, also, of “reducing/optimizing” the water dosage in respect to the cement and the active minerals, (pozzolanic) while maintaining the adequate classes of consistency/slump (S4 o S5):hh.

CLASS OF CONSISTENCY: SLUMP (mm): DENOMINATION:S1 10÷40 Wet EarthS2 50÷90 PlasticS3 100÷150 Semi-fluidS4 160÷210 FluidS5 >220 Super-fluid

7

5

3

1


For the purposes of the exposure classes (UNI 11104 and NTC-Technical Standards for Construction), the dosage employed for the FINAL MIX / IDEAL (MIX n ° A4) exceeds the minimum quantity required by the regulations in force for chemical XA2/water attachment, XD2 / chlorides, XF2-XF3/freeze-thaw, XC4/carbonatazione (w / c = 0.42 <0.45 <0.50).

The optimal MIX DESIGN must guarantee a class of consistency between S4 and S5 and the prevention of the segregation phenomena.

1


Aggregates

In compliance with the EN 206-1, UNI EN 932-3, UNI 8520, limestone aggregates from Italian quarries were used and consisted in 3 groups:

gravel: 8 ÷ 16 mmrice husk ash: 4 ÷ 10 mmsand: 0 ÷ 5 mm

The granulometric curve designed was developed by controlling the ideal curve of Bolomey. The maximum aggregate size is 16 mm.The absorption degree of the limestone aggregates was monitored, (“range” of admissible absorption) so as not to influence or distort the effective water dosage of the mix. The relationships employed of "i / c" respected the optimal values indicated in technical literature to obtain optimal performance concrete (even for shrinkage and viscosity under load). Of course it is admissible, in performing the calculations, to consider a dosage of a cement equivalent (c.eq) as including up to a maximum of 33% of fly ash/ pozzolanic aggregates, as well as the total part of the aggregates (100% of the limestone aggregates are derived from the fly ash, which is to say the remaining quota of the aggregates and pozzolanic added elements). For concrete with fly ash or milled volcanic rocks, the calculation of the equivalent aggregates and of the relationship “i/c” was conducted as follows:i.eq = gravel + rice husk ash + sand + (1-k) fly ash or milled volcanic rock

Whereas:

k = 0.33 (UNI) for the fly ash (1-k = 1- 0.33 = 0.67)

1


Aggregates (inert and active minerals):

Kg/m3 x (1-K) x K = cement equivalent

GRAVEL 350 (385) 350 (385)RICE HUSK ASH 550 (600) 550 (600)SAND 1,050 (900) 1,050 (900)First Total (aggregates) 1,950 (1,885) 1,950 (1,885)FLY ASH 100 67 33MILLED VOLCANIC ROCKSecond Total (aggregate eq.) 2,017Portland Cement I 52,5 R 320 320Third Total (cement eq.) 2,370 (2.305) 2,370 (2,305) 353

Calculations of possible relationships i/c” , “i.eq/c.eq”, “(i+cv)/c” e “i/(i+cv)”

k.1 =k.cv = 0.33 (UNI)

i/c = 1,950/320 = 6.24 i.eq /c.eq= (1,950+67)/(320+33) = 2,017/353 = 5.71(i+cv)/c=(1,950+100)/320)=2,050/320=6.40i/(c+cv)= 1,950/(320+100)=4.64

Possible values of relationships between cement and aggregates range between 4.6 and 6.4, (average 5.5) and are to be considered relatively high. As a consequence, this implicates the controllable phenomena of hygrometric shrinkage, chemical shrinkage and viscosity under load (note: in the SCC, generally speaking, the relationships “i/c” are lower and concentrated between 4.0 e 4.5, resulting in more elevated phenomena of shrinkage and above all viscosity). For the pre-compressed concrete, the hygrometric and viscosity phenomena under load are certainly discriminating factors for the evaluation of the quality of concrete and for the final cost of work performed.

Super- Plastification ( sf )

In adherence to the UNI 934-2 (3.1, 3.2, 11.1,11.2) and UNI 12350, the added super-plasticizer (sf) with a water-soluble polymer base was the minimum amount possible (sf/c). Concerning pozzolanic added elements, (fly ash or milled rock) it was 0. 85%, in respect to the effective or equivalent cement, c.eq =c + k1

x cv/rvm with k1 equal to 0.33 for the fly ash. It was, in any case, "just enough" to ensure sufficient workability of the mixture (reference: consistency class S4/S5 UNI 206-1 - Slump Loss Controlling Agent) and to prevent segregation phenomena (due to over dosage of super-plasticizer): minimum dosage of super-plasticizer equal to ~ 0.7 ÷ 1% considering both the cement and the quota (33%) of the pozzolanic minerals.The super-plasticizing additive utilized in the various MIXES that gave valid results, has a base of modified polistearici esters with a pH of approximately 4, and is free of formaldehyde and chlorides. The minimum % of plasticizing additive as noted, does not affect the final pH of the concrete. The additive was added after the insertion (for a few minutes of mixing) of the water to hydrate the mix, and was then stirred for well over 5 minutes. As evidenced by the technical and scientific literature (see Collepardi - RECENT DEVELOPMENTS IN THE FIELD OF ADDITIVES FOR CONCRETE), it was also necessary to monitor the compatibility and the creation of synergies between the super-plasticizer and the other additives / additional elements used (combined action between the super-plasticizers and the other additives / additional, non-shrinking and compacting elements with micro-expansive action). The monitoring controlled that the action did not slow down or compromise the phenomena of setting and hardening within 12 to 24 hours (essential requirement for the precast concrete industry). For example, for the MIX of 320 kg of cement without pozzolanic minerals:

1


SF = 0.01 x 320 = 3.20 kg/m3

For the MIX of 320 kg of cement with added elements of pozzolanic minerals:

SF = 0.009 x (320+0.33x100) = ~ 3.20 kg/m3

Added elements with a base of micro-expansive oxides and new generation anti-shrinkage (with modulated action in time) SEM micrographs (x1500) of the CLS at 28 days and study of the “portlandite” derived from the expansive agents and from the cement derivatives (expansive agents DRY D1 N and CEM I 52, 5 R). The micrographs enable for a clear reading of the morphology of the Portlandite in the space (frontally and laterally).

The SEM MICROGRAPH of basic cement pastes (magnification x 2.000 and x 3.500). The presence of portlandite is highlighted in yellow, respectively, in the samples “Cement paste 0 (AS IS)” and Cement Paste 1 (AS IS + DRY).

1


The new generation of concrete in the precast and c.a.p. industry requires always more of a painstaking approach to the packaging of concrete in the absence of the noted criticalities of “autogenous/hygrometric shrinkage”:

a) Shrinkage Compensating Concrete (ShCC) that provokes the initial expansion within the concrete, slightly lower than or virtually equal to the subsequent contraction due to the shrinkage (see UNI EN 1992-1-1/Eurocodice 2 + Appendix B - DM 14/01/08 par. 11.2. 10.6). The "expansion-shrinking" diagrams according to UNI / EN, ASTM, or other methodologies enable one to understand the type of action of additives on the market and their effectiveness or ineffectiveness according to the dosage (sometimes excessive).

b) Self-Consolidating Concrete (see ACI 223R-98, a very different type of concrete, but along the philological lines and trends of Self Compacting Concrete o SCC, UNI EN206-1 ) provokes a sensitive micro-expansion, slightly superior to the contemporary contraction of shrinkage in a resistant matrix, on the inside of the concrete. In the presence of formwork/ rigid constraints and of spacial scaffolding this may lead to the creation of compression stress in the growth of the young concrete (in the setting/ hardening phase). The scaffolding in the c.a., as a function of its arrangement and diameters, works for the cls expansion, thanks to its adherence and circular design. This expansion, if properly calibrated, offers benefits including decreasing viscous movements of self-compacting and self-fortification during the constitutive genesis of the young concrete, creating the foundation to enhance its future performance.

c) Volumetric Stability Controlled Concrete The external constraints applied to the structures’ scaffolding constitute a system of redundant constraints and the presence of contraction deformation that (such as the hygrometric shrinkage, negative thermal changes and heat dissipation of hydration) induce tensile stress states, which still increase the distance between the materials (facies). This exceeds the limits of concrete resistance (strength) producing macro and micro cracks. Concrete that retains its shape, with balanced and weighted expansion in the beginning, and then without shrinkage and critical stress in its genesis, as a function of its MIX DESIGN and external conditions (humidity, temperature, thickness of the jet, the jet mass, constraints, etc..) is the dream of structural engineers and is defined as "a volumetric stability control." This represents one of the principle objectives of researchers and technologies for the production of new generation concrete.

VSCC&ICME (Volumetric Stability Controlled Concrete and/with initial calibrated micro-expansion).

8

1


Above: ASTM 878 test data – Above on the right and below: instruments and software for the free shrinkage/expansion, according to Gennaro’s method.

The test to monitor the macro-expansion-contraction of the 50x50x50 mm. concrete cubes according to Gennaro’s Method begins testing by using 4 probes (on the horizontal plane) arranged in contact with steel plates embedded in the jet. The mix/preparation time is controlled. The two probes along the X-axis and the two probes along the Y-axis constantly measure the free expansion / contraction of the time "t.0" of the semi-hardened and hardened concrete until the cancellation (essentially) of the phenomena of volumetric change (t.fin). A double plastic film wraps the sample (with the exception of the contact areas of the 4 sensors) on the lateral faces of the cube (reference test type B of the UNI standard). The relative humidity and temperature are controlled by meteorological stations (generally the tests are performed in air using the following parameters: RH 50% + / - 2% and temperature 20 + / - 2 ° C). The test could also be performed by totally immersing the specimen in water (filling the tank), or varying the conditions of temperature / RH. The test allows for monitoring of the time t.0 and the volume displacements of the concrete (time t.0 generally equal to 4 hours after the jet). The apparatus provides for the possibility of inserting a further probe for monitoring the movements with respect to the Z-axis. For testing of micro-expansion/micro-shrinkage, components of a larger sized concrete are packaged (e.g. 300x300x50, etc.).

Photo X + Y – Restrained expansion test

UNI 8148 - Method B

1


Metodo UNI Metodo b

Espansione Contrastata sec. UNI 8148 met.B

CONCRETE: CEM I 52,5 R – 320kg/mc - a/c= 0.42

0

-221

0 0

-221

0

-25

-50-54

0

25

0

-42

-75-87

0

62

214

-80

-250

-313

-342

0

-150 -154

-71

-142

-192

-154

-121-83

-79

-400

-350

-300

-250

-200

-150

-100

-50

0

50

100

0 7 14 21

Time (days)

C.V. (100Kg/mc) D1 40-40-20 (7Kg/mc)

D1 30-30-40 (7Kg/mc) C.V. (100Kg/mc) + D1 40-40-20 (7,5Kg/mc)

C.V. (100Kg/mc) + D1 30-30-40 (7Kg/mc) C.V. (100Kg/mc) + D1 30-30-40 (7Kg/mc) + D1 Rapido (0,5Kg/mc)

AS IS 1 (Riferimento a secco) AS IS 2 (Relative high UM)

µ m/m

1


Gennaro’s Method SAMPLE 1:

Dimensions 50 x 50 x 50 mm(Duration measure 143h)

Experimental Test of “Macro-Expansion”Dosage of 20% of DRY NORMALE in respect to cement

Date: January 2012 (Duration measure 143h)

1


Researchers at the Department of Earth Sciences interacted with the facilities engineers of Chimica Edile to formulate different types of "micro-expansive and compacting agents" based on the scientific and technical needs of the project ("concrete with controlled volumetric stability with initial micro-expansive action of compaction and acceleration / expansion of pozzolanic activity"). A primary purpose of the research was therefore to respect the hypothesis of formulating concrete with "controllable" volumetric stability (res extensa), or a concrete that from its inception to its use is not subject to "structural / mechanical / chemical disturbances "and trauma in general" due to volumetric instability. This hypothesis is to be instantaneously detected at the end of the mixing, or by the t.0 time of the casting: after a few hours, a few days, weeks, months and ...years, regarding the minimization of "expansion / shrinkage" and of the "volumetric change". However, it would seem reasonable and rational to say that in the plastic and semi-plastic "fresh" or "semi-fresh" concrete phase, its significant expansion as described above would result in a positive compacting and strengthening effect of the concrete (a decrease in porosity and greater contact between the facies), still in the setting and hardening phase (Self Compressing + Shrinkage Free Concrete = SCompresC SHFC). The questions from the beginning of the research were the following: what is the optimal value of this micro expansion and for how long must this micro expansion be set? The only methodology able to provide a response was to constantly monitor this phenomenon (from the casting phase to the setting and hardening phase), right from the moment of casting, (t.0 ) and to then follow the chronological evolution (volumetric stability/instability) of the "Epsilon/t" diagram according to the dosage and the type of formulation provided by Chimica Edile. The Department of Earth Sciences developed a special apparatus to test this phenomenon (a cube/slab of concrete in unrestricted formwork, which permitted its free expansion/shrinkage in space, in air or in water. The test was then named Expansion/Shrinkage according to Gennaro’s Method). Furthermore, this apparatus allowed for a comparison of these results with those determined by applying international standards for obstructed shrinkage/expansion tests (UNI / ASTM standards).

Test ritiro-e spa nsione Metodo Form a e Dim . P rovino

(m m ) Prim a sta gionatura (stam po-cassa form a) Se conda sta giona tura Ulte riore sta giona tura S ca de nze m isure (giorni) Note :

A Prism a

80x80x240 Stam po: 8 ore - 20±1 C° - UR 95% Vasca con acqua satura d i ca lce: 20±1 C° per 28 giorn i - 2 - 7 - 14 - 28Es pans ione contras tata

in assenza d i ritiro

BPrism a

80x80x240 Stam po: 8 ore - 20±1 C° - UR 95%Arm adio clim atico: 20±1 C° - UR 95%

Prim i 2 g iorni: avvolti da 2 s trati d i film po lie tilene (LDPD) Success ivam ente: liberi fino a 28 giorni

- 2 - 7 - 14 - 28Espans ione contras tata

in condizioni di ritiro controllate

A

Cubo - Cilindro - Prism a D im .di base uguale a 3,5

volte dim . nom inale aggregato

Stam po: 24±1 ore - 20±2 C° - UR 95% Cam era condizionata: 20±2 C° - UR 50±5% per 90 giorni

- 2 - 3 - 7- 28 - 60 - 90 Ritiro libero

B

Cubo - Cilindro - Prism a D im .di base uguale a 3,5

volte dim . nom inale aggregato

Stam po: 24±1 ore - 20±2 C° - UR 95% Cam era condizionata: 20±2 C° - UR 50±5% per 90 giorni

- 2 - 3 - 7- 28 - 60 - 90 Ritiro l ibero superficiale

A Prism a

75x75x250 Stam po: 6 ore - 23±2 C° - UR 95% Vasca con acqua satura di calce: 23±2 C° per 7 giorniVasca con acqua satura di calce

23±2 C°7

Oltre 7 giorni: da stabilireEs pans ione contras tata

in assenza d i ritiro

B Prism a 75x75x250

Stam po: 6 ore - 23±2 C° - UR 95% Vasca con acqua satura di calce: 23±2 C° per 7 giorniAria

Condizion i di tem peratura e U.R. predeterm inate

7 Oltre 7 giorni: da stabilire

Prim i 7 g iorni: es pans ione contras tata in assenza di ritiro

Dopo 7 g iorni: espans ione contras tata in condizioni variabili

A

Prism a 100x100x285

75x75x285 - 25x25x285 (secondo dimensioni massime aggregato)

Stam po: 24 ore - 23±0,5 C° - UR 95% Vasca con acqua satura d i ca lce: 23±2 C° per 28 giorn iVasca con acqua satura di calce

23±0,5 C°

1 - 28 U lteriore s tagionatura:

8 - 16 - 32 - 64 settimane

Variazione lineare in assenza d i ritiro

B

Prism a 100x100x285

75x75x285 - 25x25x285 (secondo dimensioni massime aggregato)

Stam po: 24 ore - 23±0,5 C° - UR 95% Vasca con acqua satura d i ca lce: 23±2 C° per 28 giorn iCam era condizionata 23±2 C° - UR 50±4%

1 - 28 U lteriore s tagionatura:

4, 7 , 14, 28 giorn i 8, 16, 32 , 64 settimane

Variazione lineare in condizioni di ritiro controllate

-de'

Gennaro

Cubo - Pris m a 70x70x70

100x100x150 150x150x150

Cassaform a: 4 oreAria o acqua

Tem peratura e UR controlla te - Monitoraggio continuoVariazione lineare

in as senza d i ritiro o in condizioni di ritiro controlla te

ASTM C157

ASTM C878

UNI 11307

UNI 8148

CHECK AND COMPLETE REGULATORY FRAMEWORK ON EXPANSION/SHRINKING TESTS AND AGING TYPE in water, lime or in air; compare results to Gennaro's Method

In the following, we distinguish 3 types of micro-expansive formulations of Chimica Edile : Fast action, normal action and slow action, which allowed the research to finalize, specialize and refine its applications.

1


Table – Studio Mix Design of DRY "expansive agents" for concrete with CEM 52, 5 R with a dosage of 320 kg/m3. The dosage is expressed as a percentage of cement. For high doses of cement, the percentage of DRY D1 can be suitably reduced after the test campaign.

Type of DRY

RESEARCH PHASEDRY D1 RAPIDO DRY D1 NORMALE

DRY D1 LENTO (new generation)

Dosage 1.a research phase

1,1% 1,1%

Dosage 2.a research phase

0,6% 0,6% 1%

Micro-expansive, rapid action, oxide based additive with compacting and self-compressing effect ( e.r )

The insertion of micro-expansive, (e.r) calcium oxide based additives in the MIX, as noted, results in the following reaction:

CaO + H2O → Ca(OH)2

Reaction "immediately" and integrally involving the fine particles of highly reactive oxides (first those of a few microns and then, in outside thickness, those of a few hundred microns), produced and marketed by the CHIMICA EDILE group with the name of " DRY D1 Rapido". These oxides also have the advantage of having a high pH (> 12) that helps the durability and protection of the scaffolding in alkaline positive environments. The research and the various instruments allowed for the determination of an optimal formula and an effective dosage percentage in respect to the cement of less than 1% (e.r/c). Some of the benefits of the use of such additives involves the reduction of further ethringite formation and the expansion phenomena that occurs shortly thereafter (from the time of the mix up to about 48 hours). The action then completely ceases after a few days (the temperature obviously, strongly affects the trigger times of reactivity).

However, at the same time, the downside – if one decides only to use this type of expansive agent – is the risk of losing this expansion, or significantly reducing it, following hygrometric shrinkage. This risk occurs in environments that are not water saturated (meaning those environments not in water, not in environments regulated con U.R. near 90% or in the phase of wet sheet removal or thermo-heated places in the winter). Another risk is that this type of expansive agent may not be “effective” to control the autogenous shrinkage of concrete (meaning that which is measurable in water immersion). This type of additives produced by Chimica Edile, nevertheless, has the advantage of beginning to act (immediate micro-expansion) from the start time of the mix and in the transition days and the first creation of the fresh concrete: fluid -> semi-fluid -> plastic-> semi-solid. It is also easily mixable and diffusible in the mass of the mix (thanks to the fine grain of its particles and their capacity to spread in the mix without flocculating, because of the super-plasticizing action) and is sufficiently, less sensitive to mild, rigid and cold external temperatures (high reactivity that obviously, noticeably increases in the heat). These expansive agents based on the reaction between water and "very fine, porous particles "of calcium oxide are much faster and more direct with respect to those with a base of sulfa-aluminates with primary ethringite formation ( Candlot salt) or compared to magnesium oxides. The calcium oxides tend to expand much more quickly and autonomously compared to those based on an ethringite formation (i.e. trisolfo-calcium aluminate hydrate, 3CaO•Al2•3CaSO4•32H2O which is a salt expansive molecule that needs 32 water molecules to form). Therefore, the technicians and the market have a greater appreciation for calcium oxides with respect to those with a base of sulfa aluminates, but that have a decisively "rapid" and "short" expansive action limited in time (manifesting the expansive action in the mixture reaching a maximum in up to 2 to 3 days). To annul the final withdrawal of the cls (offset by strong final expansion) would result in excessive dosages, (in part rendered useless by the strong heat, higher temperatures greater than 25-30°C) and more

1


importantly, would lead to phenomena of strong, dimensional and volumetric non-stability, "excessive" initial expansion. It would also involve the loss of such expansion in the long term with volumetric disturbance in absolute terms, numerically similar to those of the withdrawal (several hundred microns: 300 ÷ 600 uM) although, beneficially, of opposite sign (expansion). Additional parameters that influence the speed and duration of the “rapid” expansive phenomena of calcium oxide are proportional to:

A) Its cooking temperature, cooking times, the fineness of its granules (granulametric curve and grinding process), its water-accessible porosity (characteristics of the formulate and assigned parameters of the computerized plants of the Chimica Edile group);

B) The outside temperature, the U.R., the type of aging/ form stripping of the concrete.C) The combination and type of additives combined (super-plasticizers, etc.); D) Other external factors (cement type and dosage, type and dosage of the additives, the arrangement

and quantity of scaffolding, the morphology and fineness of the aggregates, the presence of fly ash and micro-fillers, w/c, mix design, etc.)

Below is the linear performance graph, relative to the variation of the crystal size (nm) as a function of temperature (range from 900 ° C to 1400 ° C) performed on a sample of limestone rock.

1


The chemical reaction, resulting in the expansion, takes place at the "water - solid" interface. Therefore, by reducing the dimensions of the solid particles of the expansive agent and increasing its surface porosity, there tends to be an increase in the surface exposed to the action of water and thus in the "speed" of its reaction (expansive). The result is an overall acceleration of the expansion process but a shorter duration of the expansive effect over time (the concrete expands too quickly in the first few days to then withdrawal / contract and lose much of its expansion in a few days like many small balls that inflate instantly in the newly formed concrete). Similarly, if an expansive agent is in the form of porous granules accessible to water, it becomes more easily able to be hydrated, while if its granules are less fine, without excessive porosity in communication with the outside or large and dense, they are more difficult to hydrate, thus reacting more slowly and with greater tenacity. The degree of grinding, the porosity of the granules and the density of the expansive agents (CaO) are "adjustable" parameters. The manufacturer, Chimica Edile Group may vary the firing temperature of the raw material used, the firing cycle, the cooking time, the type of material (mixture of limestone and other minerals extracted and selected in the Andes) and of course its granulametric curves pre / post cooking. In addition, the manufacturer may further delay the phenomenon of hydration-expansion of the expansive agent by covering the granules (adsorption) with a suitable polymer (retardant) and with multiple processes of sintering processes. The main product resulting from the hydration of the calcium oxide is thus a "Portlandite ad hoc that may intervene intelligently, profitably, massively and temporally in the various stages of the creation of the concrete and also in the presence of pozzolanic activity within the concrete. In order to address critical issues and notes of the normal oxide-based expansive agents (rapid) -formerly emphasized- it was necessary to resort to the use of the MIX DESIGN of ulterior micro-expansive agents with compacting action and slow and tough micro-expansive action products. Chimica Edile specifically produced these products for the research objectives of the Department of Earth Sciences, which are further explained in the following paragraphs. These additional expansive agents may assist the rapid and immediate action additives, already known to scholars and the market for several years. For the purpose of the calculation of the dosage based on the weight of Cem I 52.5 R, the quantity used for the MIX n ° 10 (A4) with a base of 320 kg of CEM I 52,5 R for DRY D1 R (rapid) was obtained, for example, as follows:

r.e = 0,06 x 320 = 1,92 kg

Compacting oxide based added element with normal expansive action ( n.e )

The added element and its relative dosage of compacting additives with normal and slower action, (from 1 to 7 days) hygrometric and autogenous anti-shrinkage (e.e) with a calcium oxide mix base were performed and weighted in respect to the hypothesis of finding shrinkage or expansion (ShFC 0 Shrinkage Free Concrete) close to zero, also in medium/long term. Also incremented were the values of the compression resistance for the effect of the reduction of porosity of the conglomerate, having an accelerating and valorizing action of the pozzolanic activity in the case of pozzolanic added elements (volcanic aggregates, fly ash, micro-silica, silica fume, etc.) as in the following illustration. The triggering of the expansion phenomenon of such oxides is slower and more prolonged compared to the previous ones (rapid) and their strength is considerably higher. Therefore, the quantity must be adjusted to compensate for the size of the granules and their greater density. The research monitored the Epsilon / t diagrams with special equipment developed by the Department of Earth Sciences and compared these results to those determined by

1


applying the norms: UNI 8146, 8147, 8148, ASTM C157, C878, ACI 223R and UNI 6555. The research on the MIXES tested, allowed for the determination of an optimal dosage percentage inferior to 1% (n.e/c) For the purposes of calculating the dosage based on the weight of Cem I 52.5 R, the amount of DRY D1 Normale (normal) used for the MIX n °10 (A4) with a basis of 320 kg of CEM I 52,5 R is:

e.n = 0.06 x 320 = 1.92 kg

Special oxide based addition with slow, expansive action ( L.e )

The addition and relative dosage of additives with slow and delayed expansive action (generally 7 to 28 days) that mitigate the long-term withdrawal phenomena, (eL) based on mixtures of calcium oxides and other mineral additions, were performed and weighted. This was performed in accordance with the experience-based hypothesis of shrinkage or expansion (ShFC = Shrinkage Free Concrete) close to zero over the long term, as well. They also monitored the values of the compression resistance for the effect of the decrease in porosity of the conglomerate and of the micro-cracks from the shrinking of the hardened concrete, fragile and almost entirely dehydrated. The research monitored the Epsilon / t diagrams with special equipment developed by the Department of Earth Sciences and compared these results to those determined by applying the norms: UNI 8146, 8147, 8148, ASTM C157, C878, ACI 223R and UNI 6555. The research allowed for the determination of a dosage percentage close to 1% (L.e/c). The amount must be greater to provide for the large size of the granules and their high density and low reactivity. For the purposes of calculating the dosage based on the weight of Cem I 52.5 R, the amount of DRY D1 L (slow) for MIX n°10 with a base of 320 kg of CEM I 52.5 R is:

L.e = 0.10 x 320 = 3.20 kg

The mixing and synergy of special oxides with expansive and compacting action ( r.e+n.e+L.e )

After having studied the effects of the individual agents with expansive action, the research developed the best dosage combining the action of the three expansive agents for the purpose of optimizing their synergic action in function with the MIX DESIGN and the conditions at the boundary and externally. It should be noted that the type of cement might influence and significantly vary the micro-expansive and compacting action of the line of DRY D1 additives.

The addition of active fillers and pozzolanic minerals (fa and gvr)

In respect to the UNI EN 12620, UNI EN 450, UNI EN 197 and UNI EN 11104, UNI EN 206, as illustrated in the premise, two types of active minerals were used, that nevertheless are adequately available on the market at low costs:

fa (rv) = fly ash with pozzolanic activity and with benefits that improve the workability of the mix and that optimizes the granulametric curve of the aggregates. The maximum dosage used was close to or less than 33% of the cement dosage, (Cem 52,5 R) to ensure a minimum balance with a quantity of calcium hydroxide and enough water to activate “the pozzolanic addition”.

gvr (rvm): ground volcanic rock with pozzolanic and thermal activity (a type II classified addition). A medium sized dosage equal to 8% of the cement was used and nevertheless, always less than 33% of the dosage of cement (Cem I 52.5 R) to ensure the minimum balance with an amount of calcium hydroxide and enough water to activate the “pozzolanic addition”. This occurred with the silica fume, meta caolino, etc., as well.

In the research project, the addition of these active minerals was performed both in combined and separate forms. The phases were performed as follows: distinct MIXES without active minerals (note: only limestone aggregates in phase 1), MIXES with only additions of Fly Ash or only Ground Volcanic Rocks/Silica Fume/ Metacaolino (phase 2) and MIXES with a weighted combination of Fly Ash + ground Volcanic Rocks

1


(phase 3 in progress). This research focused on obtaining very precise comparative parameters for a correct “cost/benefit analysis”.

In order to establish the content of cement for m3 (UNI 11104:2004 for the application in Italy of the EN 206), the following, respectively, occurs:

cv/c < 0.33cv/c = 100/320 = 0.31 < 0.33c.tot = c.eq = c (Cem 52,5R) + 0.33 cv = 320 + 0.33x100 = 320 + 33 = 353 = ~ 350 kg/m3

Regarding the analysis of the size, shape and porosity characteristics of the particles (closed spheres, cenospheres and pleurospheres with accessible porosity) of the added fillers and pozzolanic minerals, (fa and gvr) the electron microscope characterized the specificities of the two distinct materials. It also highlighted the greater fineness and roundness of the fly ash (industrial) in respect to the ground volcanic rocks available today.

Figure: Comparison between the Laser granulametric distribution of native ash, micronized ash, Portland cement 42.5 and 52.5, silica fume (as is and disaggregate).

SEM MONITORING OF POZZOLANIC BEHAVIOR (in progress, beginning on July 16th)FINE SECTION (in progress, beginning on July 16th)

The ground volcanic rock presents particular thermal capacities for the presence of zeolites and is capable of significantly affecting the temperature of the fresh concrete. The temperature of fresh concrete is strongly influenced by the external temperature, but above all by the temperature of its elements. Generally, it is calculated as follows: t.cls = 0.70 t.aggregates + 0.20 t.water + 0.10 t.cement

1


SEM micrograph (magnification x2000 e x500) of the Basic MIX (AS IS + DRY 2.2%+ Fly Ash 30%) in a zone rich in microspheres of Fly Ash.

1


Protocols of research and test execution

The laboratory equipment of the Department of Earth Sciences and other collaborating laboratories allowed for the establishment, control and monitoring in time of the tests indicated in the following table.

TEST STANDARD REFERENCE NOTECompression resistance UNI 12390-3 Campioni 15x15x15, 10x010x10, etcTensile strength UNI 12372Density UNIEspansion-Shrinkage UNI 8148 – Metodo bClass consistency (SLUMP) UNI 206-1SEM, SEM-EDS on fine sectionsDef. X-RaysMercury PorosimeterWater press. absorption Atm. UNI EN 13755Ultrasound

Rck (MPa) = compression resistance to crushing of sample cubes sized 15x15x15, 10x10x10 and 7x7x7 cm of concrete and basic mixes (cement + water + additives + active minerals, in absence of aggregate additions). The resistances were established at 1 day, 7 days and 28 days (aged in water). The aging temperatures were 3, (cold, moderate, hot) in order to understand the sensitivity of the dosages and the effects of the different components according to the temperature changes.

Photo: Chassis (maximum load 3000 kN) used to establish compression resistance (Department of Earth Sciences – Università degli Studi di Napoli Federico II).

1


Photo: Chassis (Maximum load 25kN) used to establish tensile strength (Department of Earth Sciences– Università degli Studi di Napoli Federico II).

Photo: SEM (Scanning Electron Microscope) mod. Jeol JSM 5310 (CISAG, Napoli).

1


Photo: Mercury Porosimeter Thermo Finnigan of the Pascal series 140, 240 e 440 (Department of Earth Sciences – Università degli Studi di Napoli Federico II).

Photo: Automatic Panalytical Diffractometer X’Pert PRO PW 3040/60 with RTMS X’celerator detector and MPD PW 3710 unit (Department of Earth Sciences – Università degli Studi di Napoli Federico II).

1


Summary and discussion of the first research results

The research enabled us to develop some possible final MIX DESIGNS with high technical-economic competitiveness for the prefabrication and high performance concrete industry and led to some exciting new ideas for the use of new generation additives. The minimization of the shrinkage leads to, as is known, a considerable number of advantages regarding both the absence of cracks, and the different behavior of the reinforcement (especially if pre-strained). This factor also results in an increase in the durability of the concrete and the reduction of the delayed effects of micro-fillers based concrete.The presence of pozzolanic material (combined with the calcium oxides in question) besides increasing the mechanical strength in the short and mid-term, helps to improve the microstructure of concrete (for the drastic transformation of Portlandite into C-S-H fiber). The micro-expansion phenomena positively reduce the absorbency and the porosity of the concrete, thereby providing volumetric stability and avoiding stress, disruption and trauma to the concrete due to hygrometric shrinkage and coactions of internal and external hyperstaticity of the c.a and the c.a.p.All of this allows the packaging of concrete through the synergies and harmonization of the additives and additional elements studied, to be decidedly "effective, durable and economically competitive."

MIX: “Cem I 52.5 R at 320 kg/m3+ CV at 100 kg/m3+ DRY D1 L/N/R at 2.2%+ SUPER PLASTICIZING at 1%”

ELEMENTS: Kg/m3 Note:AGGREGATES 1,950.00 Sand + rice husk + gravelCEMENT I 52,5 R 320.00PLASTICIZER 3.20 1% in respect to the cementDRY D 1 RAPIDO/COMPACT 1.92 0.6% in respect to the cementDRY D 1 NORMALE/COMPACT 1.92 0.6% in respect to the cementDRY D 1 LENTO 3.20 1% in respect to the cementFA 100.00GVR Alternative useACCELERANT Cold climate (from 1% to 1.5%) WATER:WATER FOR THE CEMENT 134.00 w/c = 0.41÷0.43WATER FOR THE FLY ASH 16.00 k = 0.40 x w/c

1


Mercury Porosimetry Test

Among the many possible techniques of measurement of the pores, those of mercury intrusion and adsorption / desorption of gas are the most used techniques. The mercury porosimetry is a technique developed by Ritter and Drake in 1945 that allows you to measure the size and distribution of macropores and mesopores in porous solids (see figure below).

Figure: Measuring ranges of the techniques of mercury intrusion and for adsorption / desorption of gas.

The technique is based on the properties of mercury as a non-wetting liquid with a great variety of solids. Thanks to this characteristic, the mercury penetrates through the open pores of a solid sample under the effect of an increasing pressure. The radius of the pores penetrated is inversely proportional to the pressure exerted according to a report proposed by Washburn:

P = (2γcos Θ)/r

Whereas:P = the absolute pressure exerted; r = the radius of the pore; γ = the surface tension of the Hg

(48mN/m²); Θ = the angle of contact (141.3°).

In which some assumptions are to be taken into consideration:I. The surface tension of the mercury and the angle of contact with the solid are constant during the

analyses (480 dynes/cm is considered to be the average value); II. The pressure of the intrusion must be at the equilibrium;

III. The pores are considered cylindrical in form;IV. The solid does not deform under the effect of the pressure;V. The angle of contact (determined as 141.3°) depends on the nature of the sample and may

therefore, be considered only as an average value derived from measurements made on a large number of samples the values of which are between 125° and 152°.

In addition to these approximations, we must also assume that the porous nature of the substances and the shape of the pore remain constant throughout the entire range of pressure applied during the analysis. The experimental data for the calculation of the distribution of pores as a function of their radius was obtained from the amount of Hg penetrated into the pores of the sample and the equilibrium pressure at which the intrusion occurs.

The analysis was carried out by means of two devices of the Thermo Finnigan called PASCAL 140 and 440. Their combined use made it possible to achieve a maximum working pressure equal to 400MPa, with an accuracy better than 0.2%, providing, on a fragment of the cement paste sample, the frequency histogram of the distribution of pore volume in function of the radius with the following results:Specific pore volume, specific surface area, average pore radius, porosity percentage; Bulk Density (Bulk Density-BD); apparent density.The tests of mercury porosimetry on the aforesaid elementary cement pastes highlighted the different distribution of the radius of the pores. In particular for the cement paste sample 0 (AS IS) and the cement paste sample 1 (AS IS + EXPANSIVE) the distribution is bimodal with a concentration prevailing at the meso-pores and a more limited densification between the macro- and mesopores.

1


Cement paste 3 (with an addition of EXPANSIVE and FLY ASH to AS IS) has a uni-modal distribution with concentration of the pore sizes in the smallest range of the mesopores (figure XX) that confirms a greater homogeneity of the mass and the microstructure with evident increases in mechanical strength.

Mercury Porosimeter of fragments of a sample of the cement mixture with CEM 52,5 R + DRY+ Fly Ash

1


TEST of Water Absorption at atmospheric pressure - UNI 13755

CONCRETE MIXCem 320 kg/m3

AVERAGE ABSORPTION COEFFICIENT

H2O

NOTES

AS IS 3.00-3.10-3.20 MIX 0AS IS + DRY 2.77-2.87-2.97 MIX 1AS IS + CV 2.84-2.94-3.04 MIX 2AS IS + DRY+CV 2.58-2.68-2.78 MIX 3

Photo – Test for water absorption

1


Test of ULTRASOUND SPEED

CONCRETE MIX AVERAGE SPEED m/sec

(20 days)(Dry samples)

AVERAGE SPEED m/sec

(25 days)(Saturated samples)

AVERAGE SPEED m/sec

(28 days)(Dry samples)

NOTES

AS IS 4,700-4,900 5,000-5,200 5,000-5,250 CLS MIX 0AS IS + DRY 4,700-4,900 5,000-5,200 5,000-5,250 CLS MIX 1AS IS + CV 4,600-4,800 5,000-5,100 5,000-5,100 CLS MIX 2AS IS + DRY+CV 4,800-5,000 5,100-5,300 5,100-5,250 CLS MIX 3

Photo – Ultrasound Test on 15x15x15 cubes

1


COMPRESSION RESISTANCE TO CRUSHING TEST – UNI 12390-3

MIX A4: 320 kg/m3 of CEM I 52,5 + 100 kg/m3 of FA + 7,5 kg/m3 of DRY D1 NEW GENERATION

Resistance to compression after 1 day (temperature 20°C): 38 MPaResistance to compression after 7 days (temperature in water 20° C): 56 MPaResistance to compression after 14 days (temperature in water 20° C): 66 MPaResistance to compression after 28 days (temperature in water 20°C): 70 MPa

MIX A3: 320 kg/m3 of CEM I 52,5 + 100 kg/m3 of FA

Resistance to compression after 1 day (temperature 20°C): 29 MPaResistance to compression after 7 days (temperature in water 20° C): 42.5 MPaResistance to compression after 28 days (temperature in water 20°C): 62 MPa

MIX A2: 320 kg/m3 of CEM I 52,5 + 7 kg/m3 of DRY (AS IS + DRY)

Resistance to compression after 1 day (temperature 20°C): 37 MPaResistance to compression after 7 days (temperature in water 20° C): 45 MPaResistance to compression after 28 days (temperature in water 20°C): 49 MPa

MIX A1: 320 kg/m3 of CEM I 52,5 (AS IS)

Resistance to compression after 1 day (temperature 20°C):33 MPaResistance to compression after 7 days (temperature in water 20° C): 41 MPaResistance to compression after 28 days (temperature in water 20°C): 46 MPa

Table

SVILUPPO RESISTENZE CLS A CONFRONTO (MIX 320 Kg Cem con distinti dosaggi CV e Dry)

29

95,0

33,0

4146

37

4549

42,5

62

36,5

65

0,05,0

10,015,020,025,030,035,040,045,050,055,060,065,070,075,080,085,090,095,0

100,0105,0

1 7 28

giorni

Rck

(MPa

)

MIX A1:CEM320

MIX A2:CEM320+DRY

MIX A3:CEM320+CV100Y

MIX A4:CEM320+CV100+DRY

70

56

38

1


TEST of “TENSILE STRENGTH” for Flexure - UNI 12372

CONCRETE MIX DESIGN with 320 kg/m3 of CEM I 52,5 R

Days of maturation (in water)

MIX AS IS+CV (MPa) MIX AS IS+ CV + DRY (MPa)

AS IS (MPa)

5 days 6.15 7 days 6.9814 days 7.4121 days28 days

1


“ EXPANSION - SHRINKAGE TEST” - UNI 8148 – Method B

CEM MIX 52,5 at 320 kg/m3 + DRY 2,2% + CV 100 kg/m3

Shrinkage/Expansion UNI after 1 day (temperature of 20°C and UR 50-60%): + 60 micronShrinkage/Expansion UNI after 7 days (temperature of 20° C and UR 50-60%): + 20 micronShrinkage/Expansion UNI after 14 days (temperature of 20° C and UR 50-60%): 0 micronShrinkage/Expansion UNI after 28 days (temperature of 20° C and UR 50-60%) – 20 micron

CEM MIX 52,5 at 320 kg/m3 + CV 100 kg/m3

Shrinkage/Expansion UNI after 1 day (temperature of 20°C and UR 50-60%): -70 micronShrinkage/Expansion UNI after 7 days (temperature of 20° C and UR 50-60%): -140 micronShrinkage/Expansion UNI after 14 days (temperature of 20° C and UR 50-60%): -190 micronShrinkage/Expansion UNI after 28 days (temperature of 20° C and UR 50-60%) – 240 micron





1


Micrographs, fine sections:

At 28 days

1


TECHNICAL AND ECONOMIC ANALYSIS

Cement batching: the use of the micro-expansive / compacting additives DRY D1 leads to an increase in the compression strength between 10-15%. Such an increase may imply that the optimization of the MIX DESIGN, at the same compression strength, could involve a reduction of the cement dosage of between 5-10%.

Cement batching: the use of the micro-expansive / compacting DRY D1 combined and in synergy with pozzolanic powder leads to a further increase in compressive strength between 5-10%. Such an increase might imply that an optimization of the MIX DESIGN, for the same compressive strength, could result in a cement dose reduction of about 5-7%.

Workability: Because of its fineness, DRY D1 significantly improves the workability and slump of the fresh mixture. This workability further improves when combined with fine pozzolanic powders.

Dosage of DRY D1: the new generation of micro-expansive / compacting additives (controlled volumetric stability) allows for a reduction of up to 40% of DRY D1 to obtain a reduction of the final withdrawal.

Durability: the lower amount of water absorption, the reduced porosity and the elimination of shrinkage cracks of the concrete packaged with DRY D1, increases the durability performance.

Chemical resistance: the use of micro-expansive / compacting additives, DRY D1 in combination and synergy with powders with pozzolanic activity lead to an additional increase in chemical resistance.

1


AcknowledgementsTHE ENTIRE STAFF OF CHIMICA EDILE SRL, Engineer F. POMPONIO and Geom. S: GRUOSSO INPES SPA, the Technicians of the Laboratory of the Department of Earth Sciences, Eng. A. PASQUINI of General Admixture, DETTA SPA, CAIVANO CALCESTRUZZI SRL, Geom. N. ZACCARO,

Normative ReferencesNTC UNI EN 934-2 e UNI 12350– Plastification AdditivesUNI 8146, UNI 8147, UNI 8148 e UNI EN 1992-1-1/Eurocode 2 + Appendix B - D.M. 14/01/08 par. 11.2.10.6. ASTM C157, C878 e ACI 223R – Non metallic anti-shrinkage / expansive agents for cement mixtures. Expansion determination. UNI EN 450/2005 – Fly AshUNI 13263-3 - MARCATURA CEUNI EN 12620- Aggregates and concrete additionsUNI EN 206–2006 and UNI 11104-2004 – Concrete workability and exposition classUNI 206-1 – Consistency class of fresh concreteEN 206-1, UNI EN 932-3,UNI 8520 – Concrete aggregatesUNI EN 1008 – Water quality in concreteUNI EN 197-1 – Cements for concrete and additives / added elements classificationUNI 7123 – Concrete: the determination of the start and finish times. UNI 12390-3 – Testing hardened concrete: Compression resistance of the samples UNI EN 196-2 - Determination of acid-soluble chlorides, tenors in alkali, SO3, CaO, Al2O3 content etc. UNI EN 196-3 – Starting time of the cement pasteUNI EN 196-6 – Determination of the fineness (Residue of 90 micron m). Sieving method. UNI EN1097-7 –Volumetric massUNI 7044-Determination of mortar consistency. UNI 12390-8 – Determination of H20 penetration.

Bibliography (1) “MICRO-PORO-MECCANICA APPLICATA ALL'SCC” – MARIO COLLEPARDI, JEAN JACOB OGOUMAH OLAGOT – Politecnico di Milano – ENCO(2) “ADDITIVI ESPANSIVI E ANTIRITIRO SENZA CLORURI E SENZA FORMAZIONE DI ETTRINGITE” – ROSSANO VANNETTI – CHIMICA EDILE(3) RECENTI SVILUPPO NEL SETTORE DEGLI ADDITIVI PER CALCESTRUZZI – MARIO COLLEPARDI - ENCO(4) “TECNOLOGIA DELLA CENERE VOLANTE MICRO POZZ PFA” – G.A. – General Admixtures SpA - Rev. 2008(5) “SI PUO’ GOVERNARE IL RITIRO DEL CALCESTRUZZO ?” – N. URSI – IN CONCRETO N.99 MARZO-APRILE 2011 – ATECAP (6) “UTILIZZO DI ADDITIVI ESPANSIVI PER FRONTEGGIARE I FENOMENI DI FESSURAZIONE DA RITIRO TERMICO” – V. ROSSETTI, A. FERRARO, G.RANZO, F. ZENONE, S. ZAMPALETTA – IN CONCRETO N. 88 - ATECAP (7) “CENERI VOLANTI DELL’ENEL DI BRINDISI PER PAVIMENTAZIONI STRADALI “ – prof. Marroccoli – UNIV. BASILICATA(8) “CALCESTRUZZI SPECIALI – COLLEPARDI ET ALTRI – MAC” (9) “IL NUOVO CALCESTRUZZO – M. COLLEPARDI, S. COLLEPARDI, R. TROLI – EDIZ. TINTORETTO – 2009”(10) “COMPORTAMENTO MECCANICO DEI MATERIALI – P. DAVOLI, A. BERNASCONI, M. FILIPPINI, S. FOLETTI – MCGRAW-HILL – 2005”(11) “DEC – M. COLLEPARDI – ENCO SRL – 2011”(12) "Z come ...... ZONA DI TRANSIZIONE'", Mario Collepardi(13) “CALCESTRUZZO A RITIRO COMPRENSATO PER STRUTTURE SPECIALI” , ROBERTO TROLI, ENCO 47(14) Z. Zhibin “Synergistic effect og MgO based expansive agent and shrinkage reducing admixture on compensating the shrinkage of cementitiuos materials”, 2009

1


(15) de’ Gennaro M., Langella A., Cappelletti P., Di Bartolomeo P. Valutazione tecnica di tufi zeolitizzati provenienti da depositi dei Lazio settentrionale. 1.caratterizzazione di base. Atti 3 congresso nazionale AIMAT 1996.

(16) de’ Gennaro M., Langella A Colellea C, Pansini M. Evoluzione nell’impiego del tufo zeolitizzato: da materiale lapideo strutturale a ceramico microporoso multifunzionale. Liguori editore(17) de’ Gennaro M., Franco E., Langella A., Mirra P., Morra V. (1982) Le phillipsiti dei tufi gialli del Napoletano. Period. Monetal., 287-310.(18) de’ Gennaro M., Colella C., Franco E., Aiello R. (1983) Italian zeolites 1. Mineralogical and technical features of neapolitan yellow tuff. Industrial Minerals, 186, 46-53.(19) de’ Gennaro M., Colella C., Aiello R., Franco E. (1984) Italian zeolites 2. Mineralogical and technical features of Neapolitan campanian tuff. Industrial Minerals, 204, 97-109.(20) de’ Gennaro M., Franco E., Rossi M., Langella A., Ronca A. (1987) Epigenetic minerals in the volcanoclastic deposits from central-southern Italy: a contribution to zeolite genesis. Rend. Acc. Sc. Fis. Mat. in Napoli, Special Issue, 107-131.(21) de’ Gennaro M., Petrosino P., Conte M. T., Munno R., Colella C. (1990) Zeolite chemistry and distribution in a neapolitan yellow tuff deposit. Eur. J. Mineral.,2, 779-786.(22) de’ Gennaro M., Lagella A. (1996) Italian zeolitized rocks of technological interest. Mineral. Deposita, 451-472.(23) de’ Gennaro M., Incoronato A., Mastrolorenzo G., Adabbo M., Spina G. (1999) Depositional mechanism and alteration processes in different types of pyroclastic deposits from Campi Flegrei volcanic field Southern Italy: J. Volcanol. Geotermh. Res. 91, 303-320.(24) de’ Gennaro M., Calcaterra D., Cappelletti P., Langella A., Morra V. (2000) Building stone and related weathering in the architecture of the ancient city of Naples, Journal of Cultural Heritage, 399-414.(25) de’ Gennaro M., Cappelletti P., Langella A., Perrotta A., Scarpati C. (2000) Genesis of zeolites in the Neapolitan Yellow Tuff: geological, volcanological and mineralogical evidence, Springer-Verlag, 17-35.(26) M. Fernanda Diatz - “Disminucion de la Retracion Quimica con additivo DRY D1 en pasta de cemento blanco” - Colombia – Laboratorio I & D ARGOS - Anno 2011

Documents

1 THE PACKAGING OF HIGH-PERFORMANCE ......Concrete-Cement Industry. The research activities of the Department were conducted in collaboration with external researchers and specialists