Environmental Engineering Reference
In-Depth Information
Figure 16.9.
Direct tensile strength of concrete with lift joints - some USA dams built after 1940
(Khabbaz and Fell, 1999).
Figure 16.10.
Direct tensile strength of concrete with lift joints - some USA dams built before 1940
(Khabbaz and Fell, 1999).
Also shown on
Figure 16.11
are the ANCOLD (1991) and CDSA (1999) relationships
between tensile strength and compressive strength. It can be seen that much of the data is
lower than the guideline values.
Figures 16.12
and
16.13
show results of tests using the indirect tensile test (or splitting
test). The strengths are much higher than the direct tensile tests. EPRI (1992) attribute the
higher strengths (from the splitting test) to the testing of smaller specimens which tend to
fail through the aggregates which have a higher tensile strength than the concrete mortar.
They suggest that the splitting test is satisfactory if the core diameter is 450-900 mm. For
small core the direct tensile test is more reliable.
