New freezethaw test method for
the original weight of the specimen. A copy of the
concrete masonry units, ASTM C 1262
method is included in Appendix C.
As part of this research effort, a new test meth-
Due to the limited experience with this meth-
od was developed specifically to evaluate the
od, there are no standard freezethaw durability
freezethaw durability of concrete masonry units.
requirements for concrete masonry units using
This method was presented to the American Soci-
this method as well. Once again, however, the
ety of Testing and Materials (ASTM) and was first
method permits a comparison between the per-
published in 1994 as ASTM C 1262. Test specimens
formance of the different sets of units evaluated.
are partially submerged in water and sealed in
For reference purposes, the compressive strength,
flexible containers. Air temperatures around the
absorption, and unit weight of the concrete used
containers are controlled for thaw cycles at 20C
in these units were also determined. These val-
(68F) and for freeze cycles at 15C (5F). The
ues, measured in accordance with ASTM C 140,
method was written specifically to accommodate
have often been used in the past, with mixed re-
automatically cycling freezethaw chambers to
sults, to ensure field performance in freezethaw
perform up to three cycles per day as well as for
environments.
conventional freezers. Performance of specimens
Table 8 summarizes the data gathered during
throughout the test is determined by weight loss.
this test. As can be seen, SRW A was clearly most
Residue within the containers, the result of surface
durable. It withstood an estimated 1500 cycles of
scaling and general breakdown of the test speci-
freezing and thawing compared with less than
men, is collected and reported as a percentage of
200 cycles for all the others. Figure 17 presents the
Table 8. Average tested properties of SRW units using ASTM C
1262 and C 141.
Compressive
Unit
Specimen
No. of cycles at
strength
weight
Absorption
(kg/m3 [lb/ft3]) (kg/m3 [lb/ft3])
SRW*
1% wt loss
(MPa [psi])
1500†
A
43.8 (6351)
2138 (133.5)
98
(6.1)
G
90
52.9 (7669)
2233 (139.4)
87
(5.4)
H
180
68.9 (10,283)
2310 (144.2)
69
(4.3)
I
55
26.6 (3860)
1757 (109.7)
170
(10.6)
J
50
30.9 (4474)
1720 (107.4)
232
(14.5)
K
60
29.4 (4268)
1607 (100.3)
157
(9.8)
* SRW = Segmental retaining wall unit.
† Estimated value. Test was terminated at 875 cycles with average
weight loss of less than 0.5%.
14
12
SRW-A
SRW-G
SRW-H
10
SRW-I
SRW-J
SRW-K
8
6
4
2
0
0
200
400
600
800
1000
Number of Freeze-Thaw Cycles
Figure 17. Freezethaw test results for median specimen from each set of
segmental retaining wall units (ASTM C 1262).
19
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