ASTM C796-97
(Test Method)Standard Test Method for Foaming Agents for Use in Producing Cellular Concrete Using Preformed Foam
Standard Test Method for Foaming Agents for Use in Producing Cellular Concrete Using Preformed Foam
SCOPE
1.1 This test method furnishes a way of measuring, in the laboratory, the performance of a foaming chemical to be used in producing foam (air cells) for making cellular concrete.
1.2 This test method includes the following:
1.2.1 Manufacture of laboratory quantities of cellular concrete.
1.2.2 Determination of the air content of the freshly prepared cellular concrete and of the hardened concrete after handling in conventional machinery.
1.2.3 Determination of the following properties of the hardened concrete: compressive strength, tensile splitting strength, density, and water absorption. It may not be necessary to study all of the above properties in all cases, depending on the proposed use of the material.
1.3 The values stated in inch-pound units are to be regarded as the standard.
1.4 This standard does not purport to address all of the safety problems, 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.
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Designation:C796–97
Standard Test Method for
Foaming Agents for Use in Producing Cellular Concrete
Using Preformed Foam
This standard is issued under the fixed designation C 796; 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 (e) indicates an editorial change since the last revision or reapproval.
This standard has been approved for use by agencies of the Department of Defense.
1. Scope weight Insulating Concrete
C 496 Test Method for Splitting Tensile Strength of Cylin-
1.1 This test method furnishes a way of measuring, in the
drical Concrete Specimens
laboratory, the performance of a foaming chemical to be used
C 511 Specification for Moist Cabinets, Moist Rooms, and
in producing foam (air cells) for making cellular concrete.
Water Storage Tanks Used in the Testing of Hydraulic
1.2 This test method includes the following:
Cements and Concretes
1.2.1 Manufacture of laboratory quantities of cellular con-
C 869 Specification for Foaming Agents Used in Making
crete.
Preformed Foam for Cellular Concrete
1.2.2 Determination of the air content of the freshly pre-
pared cellular concrete and of the hardened concrete after
3. Terminology
handling in conventional machinery.
3.1 Definitions:
1.2.3 Determination of the following properties of the
3.1.1 cellular concrete—a lightweight product consisting of
hardened concrete: compressive strength, tensile splitting
portland cement, cement-silica, cement-pozzolan, lime-
strength,density,andwaterabsorption.Itmaynotbenecessary
pozzolan, or lime-silica pastes, or pastes containing blends of
to study all of the above properties in all cases, depending on
these ingredients and having a homogeneous void or cell
the proposed use of the material.
structure, attained with gas-forming chemicals or foaming
1.3 The values stated in inch-pound units are to be regarded
agents (for cellular concretes containing binder ingredients
as the standard.
other than, or in addition to portland cement, autoclave curing
1.4 This standard does not purport to address all of the
is usually employed). In cellular concrete the density control
safety concerns, if any, associated with its use. It is the
is achieved by substituting macroscopic air cells for all or part
responsibility of the user of this standard to establish appro-
of the fine aggregate. Normal-weight coarse aggregate is
priate safety and health practices and determine the applica-
usually not used but lightweight aggregates, both fine and
bility of regulatory limitations prior to use.
coarse, are often utilized in cellular concrete.
1.5 The text of this standard references notes and footnotes
3.2 Symbols:
which provide explanatory material. These notes and footnotes
(excluding those in tables and figures) shall not be considered
as requirements of the standard.
D 5 experimental density of the concrete before
ex1
3 3
pumping, lb/ft (kg/m )
2. Referenced Documents
D 5 experimental density of the concrete after pump-
ex2
3 3
2.1 ASTM Standards:
ing, lb/ft (kg/m )
C 88 Test Method for Soundness of Aggregates by Use of
D 5 theoretical density of the plastic mix based on
th
3 3
Sodium Sulfate or Magnesium Sulfate
absolute volume, lb/ft (kg/m )
3 3
C 150 Specification for Portland Cement
D 5 design density of the text mixture, lb/ft (kg/m )
d
C 192 Practice for Making and Curing ConcreteTest Speci-
SGC 5 specific gravity of cement 5 3.15
mens in the Laboratory
T 5 time required to overfill the container, min
3 3
T 5 time required to generate 1 ft (1 m ) of foam, min
C 495 Test Method for Compressive Strength of Light-
3 3
V 5 volume of foam container, ft (m )
3 3
V 5 volume of air required in the test batch, ft (m )
a
3 3
V 5 volume of test specimen (cylinder), ft (m )
c
ThistestmethodisunderthejurisdictionofASTMCommitteeC-9onConcrete
andConcreteAggregatesandisthedirectresponsibilityofSubcommitteeC09.23on
Chemical Admixtures.
Current edition approved Nov. 10, 1997. Published October 1998. Originally
published as C 796 – 74 T. Last previous edition C 796 – 87a (1993). ACI Committee 116, “Cement and ConcreteTerminology,”American Concrete
Annual Book of ASTM Standards, Vol 04.02. Institute, Publication SP-19, 1967, p. 144.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
C796
3 3 1
6.6 Strike-Off Plate for Molds—A ⁄4-in. (6-mm) thick, flat
V 5 volume of foam in the test batch, ft (m )
f
steel plate at least 8 in. (200 mm) longer and 2 in. (50 mm)
V 5 volume of water absorbed by test specimen in 24
w
3 3
wider than the diameter of the mold.
h, ft (m )
W 5 net weight of foam in overfilled container before 6.7 Scales—Scales and weights shall be accurate to within
0.1 % of the weight of the material being measured.
striking off, lb (kg)
W 5 net weight of foam in container after striking off,
6.8 Compression Machines—Compression testing ma-
lb (kg) chines used for compressive strength tests and tensile-splitting
W 5 weight of cement in the test batch, lb (kg)
strength tests shall conform to the requirements of Test
c
W 5 weight of foam in the test batch, lb (kg)
Methods C 495 and C 496, respectively.
f
W 5 total weight of water in the test batch, including
TW
6.9 Drying Oven—The drying oven shall be as described in
weight of foam, lb (kg)
Test Method C 88.
3 3
W 5 density of foam, lb/ft (kg/m )
uf
6.10 Compressed Air—A source of compressed air capable
W 5 weight of water added to test batch at mixer, lb
w
of maintaining pressures in the range of 60 to 100 psi (0.4 to
(kg)
0.7 MPa) to 61 psi (60.007 MPa).
6.11 Weighing Container for Concrete— A machined-steel
3 3
4. Summary of Test Method
container of 0.5 ft (0.014 m ) volume with a flat smooth rim.
4.1 This test method includes the following:
6.12 Strike-Off Plate for Weighing Container—A ⁄4-in.
4.1.1 Manufacture of laboratory quantities of cellular con- (6-mm)thick,flatsteelplate,atleast8in.(200mm)longerand
crete.
2 in. (50 mm) wider than the diameter of the rim of the
4.1.2 Determination of the air content of freshly prepared weighing container.
cellular concrete and of hardened concrete after handling in
6.13 Stop Watch—A stop watch graduated in seconds and
conventional machinery. minutes.
4.1.3 Determination of the following properties of hardened
6.14 Calipers—Calipers to span 3, 6, and 12 in. (76, 152,
concrete: compressive strength, tensile splitting strength, den-
and 305 mm).
sity, and water absorption. It may not be necessary to study all
6.15 Foam Weighing Container—A lightweight vessel of
3 3
of the above properties in all cases, depending on the proposed
approximately 2 ft (0.06 m ) capacity, with a smooth rim for
use of the material.
striking off.
6.16 Strike-Off Plate for Foam Weighing Container—A
5. Significance and Use
⁄4-in. (6-mm) thick, flat steel plate at least 8 in. (200 mm)
longer and 2 in. (50 mm) wider than the diameter of the rim of
5.1 This test method is used to develop data for comparison
the container.
or compliance with the requirements of Specification C 869.
6.17 Small Tools—Small tools such as a rubber-headed
hammer and a trowel shall be provided.
6. Apparatus
6.1 Mixer—The mixer shall be a power-driven paddle-type
7. Materials and Proportions
3 3
mixer with a capacity of at least 4 ft (0.12 m ), an operating
7.1 Cement—The cement used shall be Type I or Type III
speed of 40 to 45 r/min (0.24 to 0.27 kHz), and equipped with
portland cement meeting the requirements of Specification
rubber wiper blades.
C 150.
6.2 Foam Generator—The foam generator shall be a
7.2 Water-Cement Ratio—The water requirement will vary
laboratory-sizedgeneratorapprovedbythemanufacturerofthe
with the type and source of cement. For the purpose of these
foam being used and shall be similar to the type used in the
tests, w/c 5 0.58forTypeIcementand w/c 5 0.64forTypeIII
field.
cement shall be used. However, if a particular cement or
6.3 Pump—Thepumpshallbeanopenorclosedthroat-type
4 foaming agent used with these values of w/c does not produce
pump and shall be run at 450 r/min (2.7 kHz).The pump shall
3 3 a satisfactory mix, a trial mix or mixes may be made using the
be equipped with a 4.5-ft (0.13-m )“ feed” reservoir and 50 ft
cement and foaming agent in question. Pump the trial mix (see
(15 m) of open-end 1-in. (25-mm) inside diameter rubber hose
8.7.1)andrevisethe w/cif D ,theunitweightoftheconcrete
ex2
on the pump discharge, the exit end of the hose being at the
afterpumping,ismorethan10 %differentfromthedesignunit
same height as the pump.
3 3
weight of 40 lb/ft (641 kg/m ).
6.4 Curing Cabinet—The curing cabinet shall be as de-
7.3 Batch Quantities—The quantities of materials described
scribed in Specification C 511.
in Table 1 shall be used in the test batch.
6.5 Molds—The cylindrical molds for compression test
7.3.1 The foaming solution in the foam will be considered
specimens shall be as described in the Apparatus section of
as part of the total mixing water. The quantities listed in Table
Test Method C 495. The molds for all other test specimens
shall conform to the cylinder molds in theApparatus section of
Method C 192.
TABLE 1 Materials for the Test Batch
Type of Cement, Total Water, Foam,
3 3
Cement lb (kg) lb (kg) ft (m )
I 100.0 (45.36) 58.0 (26.31) 156.62/(62.4 − W ) (71.0/(1000 − W ))
uf uf
The Moyno Type CDR, Frame 2JC4 or 2L4 pump, or equivalent, has been III 100.0 (45.36) 64.0 (29.03) 160.37/(62.4 − W ) (73.0/(1000 − W ))
uf uf
found satisfactory for this purpose.
C796
3 3
1 will produce concrete weighing 40 lb/ft (641 kg/m ). The added. Discharge the mixer into the pump feed reservoir.
3 3
batch yield will be 3.95 ft (0.112 m ) for the batch using Type Immediately, proceed to 8.7.
I cement. Using the quantities for Type III cement, the yield 8.7 Weighing—Fill a tared weighing container with a rep-
3 3
will be 4.1 ft (0.116 m ). resentative sample of the concrete in the reservoir. Before
takingthesample,carefullymixtheconcreteinthereservoirto
7.3.2 The density and the yields stated in Table 1 are based
assure better uniformity without entrapping large air bubbles in
on the assumption that no accidentally entrapped air and no
the mix. Use a paddle of proper size to reach the bottom of the
change in foam volume from the calculated value exist.
reservoir. Use a scoop to transfer the concrete to the container
NOTE 1—The equation for foam volume required for the test batch may
and tap the sides of the container briskly with the rubber
be d
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