SCEBs - University of Colorado Boulder

The equation of the trend-line was used to calculate the E value for a prism with
an aspect ratio of 2 as follows:
# of Stacked
Blocks in Prism
(height = 0.9375)
ksi
1.
2111
1.
2111
y 16.
502
x 16.
502
2.
0 7.
1
Aspect
Ratio
Test Data
E [ksi]
Calculated E
from Trend-line
[psi]
Prism E value/ E
value for an aspect
ratio of 2
1 0.37 54.9 55.4 7.78
2 0.74 23.7 23.9 3.36
3 1.10 16.5 14.7 2.06
4 1.47 9.6 10.3 1.45
Table 5.4:
The last column in Table 5.4 gives the values of the ratio between each prism‟s E
value and the E value of a prism with an aspect ratio of 2.0.
5.3. On-site Testing
5.3.1. Shop Press
A simple set-up that can be used for on-site modulus of rupture (MOR) testing is
shown in Figure 5.23. It consists of a 10-ton shop press ($300 value in the U.S.) fitted
with a pressure gauge to record the applied pressure at failure. After loading the block
into the frame a hydraulic pump is used to steadily apply force until failure. The
recorded pressure at failure is converted to a force, which is used in the calculation of the
specimen‟s MOR (Section 3.9). As mentioned in Section 5.1.3, the shop press pictured is
also able to apply the force required to test the stabilized compressed earth cylinders.
The ability to perform on-site quality control tests allows for more frequent
testing of block specimens without drastically increasing project costs. Testing earthen
blocks in a laboratory facility can be expensive due to transportation costs, laboratory
fees, and time lost waiting for results. On-site testing is also beneficial during the process
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