Auto Clave Bricks

7/27/2019 Auto Clave Bricks

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App lied Mineralogy an d Non -Metal lic Resou rces II Auto claved B ui ldi ng Materi al

Autoclaved Building Material


Definition:

products

1. Lime-silica bricks


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Definition:

Autoclaved buildinproducts

1. Calcium silicate

bricks (KS

Kalksandstein)

high compressive

strength

water absorption

freezing resitance


Definition:

products

2. AAC - AeratedAutoclaved Concrete

(Porenbeton)

,blocks with high porevolume

low compressive strength

unique thermal properties

acoustic insulation


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1866: Method to cure sand and lime under steampressure was patented by Van Derburg in England

Calcium Silicate

Bricks

1880: Further development and patent by Dr. WilhelmMichalis. He succeeded in producing a real artificialsandstone

1894: Start of industrial production in Germany afterintroduction of the first rotation presses (originallydevelopped for production of cattle feed)

History

1924 first technical standard published in Germany(DIN 106) for dimensions and size tolerances (2 mm),compressive strength (15 N/mm2),


Production of

Calcium Silikate

Bricks1. Sand

2. Sand mixture

3. Lime (CaO)

4. Mixer

5. Reactor

6. 2nd mixer

7. Forming

8. Hacking

9. Autoclave

10. Steam production

11. Water supply

12. Steam

13. Storage


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1879: foundation of "Yxhult StenhuggeriAktiebolag" in Kumla , Sweden, for mining of vast

Calcium Silicate

Brickslimestone deposit situated near the city of Yxhult

Drastic shortage of energy in the 1st world war inSweden government raised the standards forthermal insulation

1918: Swedish researchers start developing new

History 1

1923: Dr. Axel Ericsson, architect and researcher atStockholm University developed a procedure formanufacturing of AAC


1928: Karl August Carln, majority shareholder of"Yxhult Stenhuggeri Aktiebolag realized the potential

Calcium Silicate

Bricksof the new building material and acquired a license formanufacturing. He invested a large part of his assets toconvert the quarry to a production facility for AAC.

1929: Start of industrial production of "YxhultsAnghrdade Gasbetong (= hardened aerated concreteof the city of Yxhult

History 2

Abreviation of "Yxhults Anghrdade Gasbetong toYtong

1940: registration of the brand name Ytong theworlds first registered brand name for a building product


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http://www.youtube.com/watch?v=x7C-QTZwMusProduction of

Aerated Autoclaved

Concrete


Mineral reaction

Quartz + Lime + Waterform new mineralphases: CSH-phases


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Mineral reaction

Reaction artners:

Quartz + Lime + Waterform new mineralphases: CSH-phases

Conditions in the

170C 8 bar

200C 16 bar


Sand + CaO + H2O

Mineral reaction in reactor

2 2

quartz into solution Ca(OH) 2 into solutionpH increases

semi-cr stalline CSH 11-Tobermorite

heating upin autoclave

C/S>1.5 C/S=0.83

semi-crystalline CSH incr. amount of withdecreasing C/S ratio 11-Tobermorite

autoclaving


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Mineral reaction

CSH- hases

Soluble in hot HCl: 11-Tobermorite

Soluble in cold HCl:

CSH-II


Mineral reaction

-phases (Tobermorite)and etched quartzcrystal


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Mineral reaction

Ex eriment of Peters /Iberg (1978) showedthe relative mobility ofthe two reactionpartners

Silica moves towardsthe source of calcium


Raw material

-Switzerland


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Comparative

study

Pure quartz-sand vssand from fluvioglacialdeposits

Amount of quartz isnot critical

impure sand can beused as raw material


Pure raw material:Sand and CaO are combined from different sources

Al ternat ive raw

material

Do rocks and other material exist that have bothreaction partners already combined?

Research project at University of Berne 1977 1986investigating: -Molasse Basin muds from gravel washeries carbonatous mudstones microstructure of autoclaved products from thesesources


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Al ternat ive raw

material

Muds from gravelwasheries


Al ternat ive raw

material

Muds from gravelwasheries


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Al ternat ive raw

material

Sandy mudstone


Al ternat ive raw

material

Clay-rich mudstone


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Preliminary study

Exam le mudstones

Analysis ofmineralogicalcomposition of 41mudstone samples

Selection of 8representative samplesfor specimen fabrication


Sampling of 40 80 kg directly from Molasse BasinSample treatment

Drying at 110 C in the laboratory oven

Jaw crusher size reduction and grinding to grain size

of < 1 mm in laboratory grinder

Pelletizing (with ideal diameter of 1 3 mm)

Analysis of mineralogical composition of untreatedsamples (XRD)

Activation of pelletized mudstone samples (after pre-study for ideal activation conditions)


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Analysis of mineralogical composition after activation

Grinding of activated pellets to grain size of


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Mineralogical

reaction

monitored w ith

autoclave XRD-

camera


Manufacturing of

samples


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Density of blocksAnalysis of

physical

Compressive strength

Tensile strength

E-Modulus

Water absorption

properties

Shrinkage and swelling

Thermal conductivity


Optical analysis

Cast sample


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Optical analysis

Thin section

Pressed sample


SEM analysis


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SEM analysis

Polished sam les

320 x


SEM analysis

1250 x


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SEM analysis

Polished sam les

5000 x


Calcium silicate bricks can be manufactured fromConclusion

,and clay minerals

Especially sandy mudstones which have not been of

economical significance seem to be most suited

This increases the volume of potential raw material forbrick manufacturing

Pressed samples manufactured of sandy mudstonescompare well with industrial calcium silicate bricks

2 patents resulted from the research program foralternative raw material for autoclaved building material

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Auto Clave Bricks