EN 934 Admixtures for concreteCurrent status and development in progress

Loro FrancescoEnvironmental Protection Agency – Veneto Region – Waste Observatory

Haifa, July 17 2018

What is EN 934

• EN 934 has been developed under by CEN TC 104/SC/3• It is group of technical regulations on Admixtures for concrete• Based on EU Regulation n. 305/2011 CPR, Admixture shall be CE labelled

• Any product shall be tested to obtain the Declaration of Performace by producer

• The control body assigns the CFP

What is EN 934

EN 934 is split into 6 parts:

• Part 1. Common requirements. Published 2008

• Part 2. Concrete admixtures. Last review: 2012

• Part 3. Admixtures for mortar. Last review: 2012

• Part 4. Admixtures for grout. Last review: 2009

• Part 5. Admixtures for sprayed concrete Published: 2007

• Part 6. Sampling, conformity control, evaluation of conformity, marking and labelling. Published 2001

EN 934-2 – Definition, requirements, conformity, marking and labelling

• General Requirements• Uniformly dispersed in Concrete

• All administure shall be conform to general requirements definined in EN 934-1 Table 1 Clause 5 and Clause 6

ClassificationType Function Reference to Table

Water reducing/plasticizing Reduce the quantity of water without affecting the consistence, or wich with the same amount of water increase the slump/flow

2

High range water reducing/super plasticizing

High reduction of water amount without affecting the consistence or atthe same amount of water increase the slump considerably

3.1 – 3.2

Water retaining Adm. wich reduce the loss of water by reduction of bleeding 4

Set Accelerating Adm. That decrease the time to commercement of transition from plastic to rigid state

6

Air entraining Adm. wich allows a controlled quantity of small uniformly distribuitedbubbles to be incorporated during mixing and remain after hardening

5

Hardening Accelerating Adm. Which increases the rate of development of early strenght in tehconcrete, with or without affecting setting time

7

ClassificationType Function Reference to EN

Set retarding Adm. Which extendes the time to rate of development of earlystrenght in the concrete, with or without affecting setting time

8

Water resisting Adm. Which reduce the capillary absorption of hardened concrete 9

Set retarding/water reducing/plasticizing

Adm. Which produces the combined effects of ahigh range water reducing/superplasticizing (primary function) and a set retarding adm(secondary function)

10

Set retarding/high water reducing / superplasticizing

Adm. Which produces the combined effects of a water reducing/plasticizing (primary function) and a set retarding adm(secondary function)

11.1 11.2

Set accelerating/water reducing/plasticizing

Adm. Which produce the combined effects of a water reducing/plasticizing adm (primary function) adn a set of acceleratingadm

12

Viscosity Modifing Adm Adm. That limit segregration by improving the cohesion 13

Plasticizing and superplasticizing

The most famous is Ligninsuphonate(developed during the ‘70) derived from paper production

Other products are gluconate and glucoseThey act as surfactans and have the abilityto disperse or deflocullate cementparticles within the mix.

Materials used to manufacture superplasticisers include:• Naphthalene formaldehyde (introduced in Japan 1963)Melamine formaldehyde condensates (introduced in Germany in 1964)• Modified lignosulfonate• Synthetic polymers

Plasticizing and superplasticizing

Water retaining admixture

This kind of admixture has been replaced by the use of fly ashes: same effect, less cost.

Air Entraining admixtures

Air Entraining admixtures (AEA)

Increase the resistestance to low T and ice, improve workabilityThe bubbles must have a spacing of 300-400 umThe quantity of admixture added to concrete is tipically very low: 0,04 –0,06%Substances uses as AEA:• Natural wood resins• Animal and wegetable oils and fats• Wetting agent and surfactants• Water solubel soaps• Vinsol resin and Darex are the most important AEA

Set Accelerating Admixtures (SAA)

Set Accelerating Admixtures (SAA)

• They are used when it isnecessary to operate in coldweather conditions or for shotconcrete (spritz beton)

• No effects on performance as resistance of concrete

• Material used as SAA: CaNO3, TEA (Tri-ethanol-ammine),

Hardening accelerating admixture (HAA)

The use of this kind of Admixtures are slowly decreasing because the use of superplasticizing admixtureintroduce the collateral effect of HAA

Set Retarding Admixtures

The use of SRA is decreasing thanks to the use of superplasticizing with combined effect of SRA

Water resisting admxture (WRA)

Viscosity Modifing Admixtures

The role of CE labelling

• European adopted in 2011 a specific regulation on construction materials: Regulation 305/2011

• It was entered in force in 2013, replancing the previous Dir. 89/106

• This regulation is the same all over EU Member States

• It was introduces to obtain a “real” single market for construction materials, without nationals specification

• To simplify the labelling process• Increase the trust on CE labelling• Increase the sustainability of products

The content of Reg. 305/2011

• New definitions:• ‘essential characteristics’ means those characteristics of the construction

product which relate to the basic requirements for construction works;

• product-type’ means the set of representative performance levels or classes of a construction product, in relation to its essential characteristics, produced using a given combination of raw materials or other elements in a specific production process;late to the basic requirements for construction works;

• ‘harmonised standard’ means a standard adopted by one of the European standardisation bodies listed in Annex I to Directive 98/34/EC, on the basis of a request issued by the Commission, in accordance with Article 6 of that Directive;

• ‘factory production control’ means the documented, permanent and internal control of production in a factory, in accordance with the relevant harmonised technical specifications;

EN 934-

2

The annex ZA of an harmonized standard describe the essencial charachteristcs for the product

Assessment and Verification of constancy of perfomarce (Art. 28)Annex V of reg 305/2011

Obbligation of Manufacter:• Determination of product-type • Factoy Production Control• Testing on sample based on plan

Obbligation of notifier:• Initial inspection of manufactury plan and

FPC• Continuos surveillance, assessment and

evaluation of FPC

Future developement on EN 934-2

• EU Commission will renew the mandate to CEN to develop the current legislation

• EN 934 will be sujbcted to the periodicreview (every 5 years)

• The next topic will be the definition of standard for two new group of admixture:• Viscosity Modifying admixture

• Shrinkage reducing admixture

• The WG is working on the new version of EN 934-6 on sampling of admixture

Aknowledgement:

Dr. Francesco Surico – Mapei Spa

ASSIAD Italian Association of Concrete Admixture Producer

Thanks for your attention

Francesco Loro

Contacts:

francesco.loro@arpa.veneto.it