Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Bagan, Myanmar
Capital of Kindom of
Pagan
Autoclaved Building Material
Between the 11th and
13th centuries, over
10’000 Buddhist
temples, pagodas and
monasteries were
constructed.
The remains of over
2200 temples and
pagodas still survive to
the present day.
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Dhammayangyi
Bricks fit very well,
almost no gaps.
Dhammayangyi
Was built during the
reign of King Narathu
(1167 – 1170)
It is reported that
Narathu’s inhumanity
hit also the brick
masons. They were
executed if he could
stick a needle between
the bricks.
Narathu is know to
have been very cruel.
He had murdered his
father and later killed
his wife in violent
temper.
Binding material: not
clear what was used or
added – varnish or
sugary sap of Palmyra
palm trees.
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Binding Material
and Mortar
• Produced by calcining gypsum to form a semihydrate
Binding Material
and Mortar
• Produced by calcining limestone to form a quick lime
• CaCO3 + Heat → CaO+ CO2
Gypsum
• CaSO4·2H2O + Heat → CaSO4·0.5H2O + 1.5H2O
(released as steam)
Lime
• Quick lime is hydrated to form slaked lime
• CaO+ H2O → Ca(OH)2
• Hardens when adding water. Water is bound and
gypsum is formed.
• Gypsum is slightly soluble in water
• Can only be used for finish of walls and ceilings or as
dry walls
Carbonate binding
material
• Slaked lime is mixed with sand to form mortar
• The slaked lime in the mortar begins to react with
carbon dioxide to form calcium carbonate while water
is released Æ the mortar hardens
• Ca(OH)2 + CO2 → CaCO3 + H2O
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Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Binding Material
and Mortar
Binding Material
and Mortar
Lime
Cement
Carbonate binding
material
Hydraulic binding
material
•
Autoclaved Building Material
“hydraulic” cement: cement that not only hardens by
reacting with water but also forms a water-resistant
product Æ various types of calcium silicate hydrates
• Roman concrete: Produced by adding volcanic ash
(pozzolana) to quick lime
• Portland cement: made by calcining limestone and
marl to form a clinker; after pulverization forms a
hydraulic binding material mainly consisting of
calcium silicates
• For details see lesson on cement of Prof. B. Grobéty
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved building
products
Autoclaved building
products
1. Calcium silicate
bricks (KS –
Kalksandstein)
2. AAC - Aerated
Autoclaved Concrete
(Porenbeton)
• high density bricks
• lightweight, low density
blocks with high pore
volume
• high compressive
strength
Autoclaved Building Material
• low compressive strength
• water absorption
• unique thermal properties
• freezing resistance
• acoustic insulation
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Calcium Silicate
Bricks
• 1866: Method to cure sand and lime under steam
pressure was patented by Van Derburg in England
History 1
• 1880: Further development and patent by Dr. Wilhelm
Michaëlis. He succeeded in producing a real “artificial
sandstone”
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Production of
Calcium Silicate
Bricks
Overview
• 1894: Start of industrial production in Germany after
introduction of the first rotation presses (originally
developed for production of cattle feed)
• 1924 first technical standard published in Germany
(DIN 106) for dimensions and size tolerances (2 mm),
compressive strength (15 N/mm2),
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Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Production of
Calcium Silicate
Bricks
1.
Applied Mineralogy and Non-Metallic Resources II
AAC
• 1879: foundation of "Yxhult Stenhuggeri
History 1
Aktiebolag" in Kumla , Sweden, for mining of vast
limestone deposit situated near the city of Yxhult
Sand
2.
Sand mixture
3.
Lime (CaO)
4.
Mixer
5.
Reactor
6.
2nd mixer
7.
Forming
8.
Hacking
9.
Autoclave
Autoclaved Building Material
• Drastic shortage of energy in the 1st world war in
Sweden Æ government raised the standards for
thermal insulation
• 1918: Swedish researchers start developing new
building material to meet the requirements
• 1923: Dr. Axel Ericsson, architect and researcher at
Stockholm University developed a procedure for
manufacturing of AAC
10. Steam production
11. Water supply
12. Steam
13. Storage
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
AAC
• 1928: Karl August Carlèn, majority shareholder of
History 2
"Yxhult Stenhuggeri Aktiebolag„ realized the potential
of the new building material and acquired a license for
manufacturing. He invested a large part of his assets to
convert the quarry to a production facility for AAC.
Applied Mineralogy and Non-Metallic Resources II
Production of
Aerated Autoclaved
Concrete
Autoclaved Building Material
http://www.youtube.com/watch?v=empEMs2zmA&feature=related
•1929: Start of industrial production of "Yxhults
Anghärdade Gasbetong„ (= hardened aerated concrete
of the city of Yxhult
• Abreviation of "Yxhults Anghärdade Gasbetong„ to
Ytong
• 1940: registration of the brand name Ytong Æ the
world‘s first registered brand name for a building product
Applied Mineralogy and Non-Metallic Resources II
Mineral reaction
Autoclaved Building Material
xCaO + ySiO2 + zH2O → (CaO)x(SiO2)y(H2O)z
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Mineral reaction
Reaction partners:
Reaction partners:
Lime + Quartz + Water
form new mineral
phases: CSH-phases
Quartz + Lime + Water
form new mineral
phases: CSH-phases
Conditions in the
autoclave:
170°C
Æ 8 bar
200°C
Æ 16 bar
3
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Sand + CaO + H2O
Mineral reaction
Mineral reaction
in reactor
Sand + Ca(OH) 2 + H2O
heating up
in autoclave
quartz into solution
Ca(OH) 2 into solution
pH increases
semi-crystalline CSH
C/S>1.5
11Å-Tobermorite
C/S=0.83
semi-crystalline CSH
decreasing C/S ratio
incr. amount of with
11Å-Tobermorite
CSH-phases
Soluble in hot HCl:
Æ 11Å-Tobermorite
Soluble in cold HCl:
Æ CSH-II
autoclaving
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Mineral reaction
Mineral reaction
Newly formed CSHphases (Tobermorite)
and etched quartz
crystal
Experiment of Peters /
Iberg (1978) showed
the relative mobility of
the two reaction
partners
Autoclaved Building Material
Æ Silica moves towards
the source of calcium
Applied Mineralogy and Non-Metallic Resources II
Raw material
Quartz-rich sands in
Switzerland
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Comparative
study
Pure quartz-sand vs
sand from fluvioglacial
deposits
ÆAmount of quartz is
not critical
Æ impure sand can be
used as raw material
4
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
SEM analysis
SEM analysis
Polished sample of
Siporex
Polished sample of
Siporex
40 x
640 x
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Autoclaved Building Material
We learned earlier that Dr. Wilhelm Michaëlis
succeeded in producing a real “artificial sandstone”.
SEM analysis
Alternative raw
material
Polished sample of
Siporex
2500 x
Pure raw material:
ÆSand and CaO are combined from different sources
Do rocks and other material exist that have both
reaction partners already combined?
ÆResearch project at University of Berne 1977 – 1986
investigating:
• carbonate-bearing sandstones from the Swiss
Molasse Basin
• muds from gravel washeries
• carbonatous mudstones
• microstructure of autoclaved products from these
sources
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Alternative raw
material
Alternative raw
material
Muds from gravel
washeries
Muds from gravel
washeries
Autoclaved Building Material
5
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Alternative raw
material
Alternative raw
material
Sandy mudstone
Clay-rich mudstone
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Preliminary study
Applied Mineralogy and Non-Metallic Resources II
Sample treatment
Autoclaved Building Material
Autoclaved Building Material
• Sampling of 40 – 80 kg directly from Molasse Basin
Example mudstones
• Drying at 110° C in the laboratory oven
Analysis of
mineralogical
composition of 41
mudstone samples
• Jaw crusher size reduction and grinding to grain size
of < 1 mm in laboratory grinder
• Pelletizing (with ideal diameter of 1 – 3 mm)
Sample selection
• Analysis of mineralogical composition of untreated
samples (XRD)
Selection of 8
representative samples
for specimen fabrication
• Activation of pelletized mudstone samples (after prestudy for ideal activation conditions)
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
• Analysis of mineralogical composition after activation
• Grinding of activated pellets to grain size of <0.5 mm
Sample treatment
continued
• Hydration and casting/pressing in moulds
Sample
fabrication
• Analysis of mineralogical composition after hydration
• Hardening in autoclave ( 2 hrs heating 20 – 200°C, 6
hrs soaking time, 3 hrs cooling time)
• Analysis of mineralogical composition of end product
• Chemical analysis of content of quartz and new
phases
• Analysis of physical properties
• Thin section analysis
6
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Monitoring of
mineral reaction
during hardening
Autoclaved Building Material
Mineralogical
reaction
monitored with
autoclave XRDcamera
X-ray diffraction with a
autoclave camera
Applied Mineralogy and Non-Metallic Resources II
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Manufacturing of
samples
Applied Mineralogy and Non-Metallic Resources II
Analysis of
physical
properties
Autoclaved Building Material
• Density of blocks
• Compressive strength
• Tensile strength
• E-Modulus
• Water absorption
• Shrinkage and swelling
•Thermal conductivity
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
Optical analysis
Optical analysis
Thin section
Thin section
Cast sample
Pressed sample
Autoclaved Building Material
7
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
SEM analysis
SEM analysis
Crushed samples
Polished samples
Autoclaved Building Material
320 x
Applied Mineralogy and Non-Metallic Resources II
Autoclaved Building Material
Applied Mineralogy and Non-Metallic Resources II
SEM analysis
SEM analysis
Polished samples
Polished samples
1250 x
5000 x
Applied Mineralogy and Non-Metallic Resources II
Conclusion
Autoclaved Building Material
Autoclaved Building Material
• Calcium silicate bricks can be manufactured from
alternative raw material consisting of carbonate,
quartz 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 for
brick manufacturing in Switzerland
• Pressed samples manufactured of sandy mudstones
compare well with industrial calcium silicate bricks
• 2 patents resulted from the research program for
alternative raw material for autoclaved building
material
8