ASTM C1693-11(2017)
(Specification)Standard Specification for Autoclaved Aerated Concrete (AAC)
Standard Specification for Autoclaved Aerated Concrete (AAC)
SCOPE
1.1 This specification covers autoclaved aerated concrete (AAC), a cementitious product based on calcium silicate hydrates in which low density is attained by the inclusion of an agent resulting in macroscopic voids, and in which curing is carried out using high-pressure steam.
1.2 The raw materials used in the production of autoclaved aerated concrete are portland cement or blended cements, quartz sand, water, lime, gypsum or anhydrite, and an agent resulting in macroscopic voids. The quartz sand used as a raw material may be replaced by a siliceous fine aggregate other than sand, and usually is ground to a fine powder before use. Fly ash may be used as a sand replacement. The batched raw materials are mixed thoroughly together to form a slurry. The slurry is cast into steel molds. Due to the chemical reactions that take place within the slurry, the volume expands. After setting, and before hardening, the mass is machine cut into units of various sizes. The units then are steam-cured under pressure in autoclaves where the material is transformed into a hard calcium silicate.
1.3 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. See Section 6, 7, and 8.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
General Information
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Standards Content (Sample)
This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the
Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
Designation: C1693 −11 (Reapproved 2017)
Standard Specification for
Autoclaved Aerated Concrete (AAC)
This standard is issued under the fixed designation C1693; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope 2. Referenced Documents
1.1 This specification covers autoclaved aerated concrete 2.1 ASTM Standards:
(AAC), a cementitious product based on calcium silicate C22/C22M Specification for Gypsum
hydrates in which low density is attained by the inclusion of an C33 Specification for Concrete Aggregates
agent resulting in macroscopic voids, and in which curing is C39/C39M Test Method for Compressive Strength of Cylin-
carried out using high-pressure steam. drical Concrete Specimens
C144 Specification for Aggregate for Masonry Mortar
1.2 The raw materials used in the production of autoclaved
C150 Specification for Portland Cement
aerated concrete are portland cement or blended cements,
C332 Specification for Lightweight Aggregates for Insulat-
quartz sand, water, lime, gypsum or anhydrite, and an agent
ing Concrete
resulting in macroscopic voids. The quartz sand used as a raw
C595/C595M Specification for Blended Hydraulic Cements
material may be replaced by a siliceous fine aggregate other
C618 Specification for Coal Fly Ash and Raw or Calcined
than sand, and usually is ground to a fine powder before use.
Natural Pozzolan for Use in Concrete
Fly ash may be used as a sand replacement. The batched raw
C1692 Practice for Construction and Testing of Autoclaved
materials are mixed thoroughly together to form a slurry. The
Aerated Concrete (AAC) Masonry
slurry is cast into steel molds. Due to the chemical reactions
E4 Practices for Force Verification of Testing Machines
that take place within the slurry, the volume expands. After
E575 Practice for Reporting Data from Structural Tests of
setting, and before hardening, the mass is machine cut into
Building Constructions, Elements, Connections, and As-
units of various sizes. The units then are steam-cured under
semblies
pressure in autoclaves where the material is transformed into a
hard calcium silicate.
3. Classification
1.3 The values stated in inch-pound units are to be regarded
3.1 AAC units manufactured in accordance with this speci-
as standard. The values given in parentheses are mathematical
fication are classified according to their strength class.
conversions to SI units that are provided for information only
and are not considered standard.
4. Materials and Manufacture
1.4 This standard does not purport to address all of the
4.1 Raw Materials—Materials shall conform to the follow-
safety concerns, if any, associated with its use. It is the
ing applicable specifications:
responsibility of the user of this standard to establish appro-
4.1.1 Portland Cement, Specification C150.
priate safety and health practices and determine the applica-
4.1.2 Blended Cements, Specification C595/C595M.
bility of regulatory limitations prior to use. See Section 6, 7,
4.1.3 Pozzolan, Specification C618.
and 8.
4.1.4 Gypsum, Specification C22/C22M.
1.5 This international standard was developed in accor-
4.1.5 Aggregates, Specifications C33, C144,or C332.
dance with internationally recognized principles on standard-
ization established in the Decision on Principles for the
5. Physical Requirements
Development of International Standards, Guides and Recom-
mendations issued by the World Trade Organization Technical
5.1 Compressive Strength—The compressive strength shall
Barriers to Trade (TBT) Committee.
be determined according to Section 6 and shall conform to the
requirements of Table 1.
This specification is under the jurisdiction ofASTM Committee C27 on Precast
Concrete Products and is the direct responsibility of Subcommittee C27.60 on
Precast Autoclaved Aerated Concrete. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
CurrenteditionapprovedJune1,2017.PublishedJuly2017.Originallyapproved contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
in 2009. Last previous edition approved in 2011 as C1693 – 11. DOI: 10.1520/ Standards volume information, refer to the standard’s Document Summary page on
C1693-11R17. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
C1693 − 11 (2017)
A
TABLE 1 Physical Requirements
Strength Class Compressive Strength, Nominal Dry Density Limits,
3 3
psi (MPa) Bulk Density, lb/ft (kg/m )
3 3
min lb/ft (kg/m ) Lower Limit > Upper Limit#
AAC-2 290 (2.0) 25 (400) 22 (350) 28 (450)
31 (500) 28 (450) 34 (550)
AAC-3 435 (3.0) 31 (500) 28 (450) 34 (550)
37 (600) 34 (550) 41 (650)
AAC-4 580 (4.0) 31 (500) 28 (450) 34 (550)
37 (600) 34 (550) 41 (650)
AAC-5 725 (5.0) 37 (600) 34 (550) 41 (650)
44 (700) 41 (650) 47 (750)
AAC-6 870 (6.0) 37 (600) 35 (550) 41 (650)
44 (700) 41 (650) 47 (750)
A
The average drying shrinkage requirement of all strength classes is#0.02 %.
5.2 Dry Bulk Density—The dry bulk density shall be deter- rate of travel of the moving head such that the remaining load
mined according to Section 7 and shall conform to the is applied in not less than one nor more than two minutes.
requirements of Table 1.
6.3.3 Calculate the compressive strength of each specimen
as follows:
5.3 Drying Shrinkage—The drying shrinkage shall be deter-
mined in accordance with Section 8, and shall conform to the P
Compressivestrength, f 5 (1)
requirements of Table 1. A
5.4 Modulus of Elasticity—If required, the modulus of
where:
elasticity shall be determined in accordance with Section 9.
f = compressive strength of the specimen, psi (or Pa),
P = maximum load, lbf (or N), indicated by the testing
6. Determination of Compressive Strength
machine, and
2 2
A = gross cross-sectional area of the specimen, in. (mm ).
6.1 Apparatus:
6.1.1 Testing Machine—The testing machine shall conform
6.4 The compressive strength shall be reported to the
to the requirements prescribed in Practice E4. The machine
nearest 10 psi (69 kPa) for each specimen and as the average
shall be equipped with two steel bearing blocks one of which
for three specimens.
is a spherically seated block that will transmit load to the upper
surface of the specimen, and the other a plane rigid block on
7. Determination of Moisture Content and Bulk Density
which the specimen will rest.
7.1 Apparatus:
6.2 Test Specimens:
7.1.1 Balance—shall be sensitive within 0.5 % of the mass
6.2.1 Three cube specimens of 4 in. (100 mm) edge length
of the specimen.
shall be tested in an air dried condition (5 to 15 % by mass
7.2 Test Specimens—Three test specimens, as described in
moisture content). If the samples have to be dried before
8.2, shall be used for calculating the bulk density.
testing to reach that moisture content, they shall be stored at a
temperature not exceeding 158°F (70°C).
7.3 Procedure:
6.2.2 Aminimum of three specimens shall be tested. When- 7.3.1 Determine the mass of the specimens, and then dry
ever possible, one specimen shall be obtained from the upper
them in a ventilated oven at 212 to 230°F (100 to 110°C) for
third of the product, one from the middle, and one from the
not less than 24 h, and until two successive determinations of
lower third, determined in the direction of the rising of the
mass at intervals of 2 h show an increment of loss not greater
mass during manufacture. Otherwise, the position of the cubes
than 0.2 % of the last previously determined mass of the
and information regarding the rise shall be reported. The
specimen.
direction of the rise shall be noted on all specimens. This is
7.3.2 Calculate the moisture content of each specimen as
shown in Fig. 1.
follows:
6.2.3 Loadbearing surfaces of the specimen shall be plane
Moisture Content%, MC 5 A 2 B /B 3100 (2)
~ !
within 0.0035 in. (0.09 mm) per 4 in. (100 mm). This can be
where:
achieved by grinding, milling, or capping. When capping, a
gypsum plaster compound shall be used.
MC = moisture content, %,
A = sampled mass of specimen, lb (kg), and
6.3 Procedure:
Bto = dry mass of specimen, lb (kg).
6.3.1 The specimen shall be placed in the testing machine
and the load applied perpendicular to the direction of rise 7.3.2.1 Report the average moisture content of all of the
specimens as the moisture content of the lot.
during manufacture.
6.3.2 Speed of Testing—Apply the load up to one half of the 7.3.3 Determine the dimensions of the test specimens with a
expected maximum load at a convenient rate, after which caliper gauge. Measure the width and height at the ends and in
adjust the controls of the machine as required to give a uniform the middle of the length of the specimen. Measure the length
C1693 − 11 (2017)
FIG. 1 Direction of Loading
on two opposite sides. Determine the volume of the specimen 7.3.4.1 Report the average dry bulk density of all of the
by multiplying the average values of the dimensions. specimens as the dry bulk density of the lot.
7.3.4 Calculate the dry bulk density of each specimen as
follows:
8. Determination of Drying Shrinkage
γ 5 B/V (3)
8.1 Apparatus:
where:
8.1.1 Balance, shall be sensitive to within 0.1 % of the mass
3 3
γ = dry bulk density, lb/ft (kg/m ), of the specimen.
B = dry mass of specimen, lb (kg), and
8.1.2 Caliper Gauge, shall be accurate to 0.004 in. (0.1
3 3
V = volume of the specimen, ft (m ).
mm).
C1693 − 11 (2017)
8.1.3 Temperature Regulated Environment, capable of regu- 8.4 Determination of Drying Shrinkage:
lating the temperature to 68 6 4°F (20 6 2°C) and a minimum
8.4.1 Clean the measurement marks before each reading.
relative humidity of 45 % in which the samples are stored
Make the first determination of length and mass immediately
during drying and while the measurements in the change in
after removing the specimen from the plastic enclosure. Then
length are performed.
storethespecimenonagridtoallowsufficientmovementofair
8.1.4 Measuring Instrument, used to determine the change
around the specimens in an atmosphere of 68 6 4°F (20 6
in length of the test samples. Any suitable device shall be
2°C) and a minimum relative humidity of 45 %. Determine
permitted to be used provided it meets the following require-
each specimen’s mass and length at regular intervals until the
ments:
moisture content has decreased to below 4 %. At least five
8.1.4.1 Theinstrumentshallmeasurechangeinlengthalong determinations shall be made.
the longitudinal axis of the sample.
8.4.2 The test specimens shall be stored in a drying cabinet
8.1.4.2 The instrument shall be able to make contact with
at 220 6 8°F (105 6 5°C) until the mass at two determinations
the measurement marks fastened to the face of the samples.
does not change by more than 0.2 %. After a constant mass is
8.1.4.3 The measurements shall be made with an accuracy
reached, the measurement marks shall be removed, and the
-6
of ∆L/L ≤ 10 , where L is the original length of the
mass determined.
[ogr] [ogr]
sample
8.5 Calculation of Test Results:
8.1.4.4 The instrument shall have a measuring precision
8.5.1 Calculate the relative change in length between read-
consistent with the accuracy required in 8.1.4.3.
ings as follows:
8.1.4.5 The instrument shall be checked with a measure-
L 2 L
ment standard prior to each measurement. ~ ! ∆L
ogr f
@ #
ε 5 3100 5 3100 (5)
si
8.1.5 Measurement Marks, fastened to the faces of the L L
@ogr# @ogr#
samples, shall be made of a corrosion-resistant material and
where:
shapedsothatreliablecontactwiththemeasuringinstrumentis
∆L = change in measured length according to 8.4.1 in in.
assured.
(mm),
8.1.6 Ventilated Drying Oven, capable of maintaining a
L = the initial length of the specimen, and
[ogr]
temperature of 220 6 8°F (105 6 5°C).
L = the final length of the specimen.
f
8.2 Test Specimens:
8.5.1.1 The relative change in length shall be reported with
8.2.1 Use prism specimens measuring 1.5 by 1.5 by 6.3 in.
an accuracy of 0.00001 in./in. (0.00001 mm/mm).
(40 by 40 by 160 mm), and use at least three specimens for
8.5.2 The moisture content at each reading time shall be
each test. Whenever possible, obtain one specimen from the
calculated as follows:
upper third of the product, one from the middle, and one from
the lower third, determined by the direction of the rising of the
~m 2 m !
i d
MC 5 3100 (6)
mass during manufacture. Otherwise, report the position of the m 2 m
~ !
d mark
sample and the direction of rise. Note the direction of rise on
where:
all specimens.
MC = moisture content,
8.2.2 The longitudinal axis of the specimen shall be normal
m = mass of the damp sample at the reading time in lb
i
to the direction of rise and preferably parallel with the
(kg),
longitudinal direction of the product. Cement the measurement
m = mass of the sample unit after drying in lb (kg), and
d
marks or otherwise securely fasten them to the faces of the
m = mass of the measurement mark in lb (kg).
mark
specimen.
8.5.2.1 The moisture content shall be reported with an
8.3 Measurement and Conditioning of Test Specimens:
accuracy of 0.1 %.
8.3.1 Measure the dimensions of the test specimens with a
8.5.3 The average values for the relative change in length
caliper gauge. Measure the width and height at the ends and in
and the moisture content for each reading shall be shown
the middle of the length of the specimen. Measure the length
graphically and connected by a curve (Fig. 2). The amount of
on two opposite sides. Determine the volume of the specimen
drying shrinkage,ε , is the difference in the relative change in
cs
by multiplying the average values of the dimensions.
length between the moisture contents of 30 and 6 %.
8.3.2 The samples shall be packaged in plastic and stored
for a minimum of 24 h at 68 6 4°F (20 6 2°C) to obtain a
9. Determination of the Modulus of Elasticity of AAC in
uniform moisture distribution. The moisture content shall be
Compression
determined as follows:
9.1 Test Apparatus—The test apparatus shall be as follows:
MC 5 ~γm 2 γdb!/γdb 3100 (4)
9.1.1 Testing Machine—The testing machine shall conform
where:
to Practices E4 (Constant-Rate-of-Traverse CRT-Type Testing
γm = m /V, wet bulk density as determined by the mass in
m Machine). The spherical head and bearing blocks shall con-
the damp condition divided by the volume, and
form to the Apparatus section of
...
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