Retrospective Evaluation of Cured-in-Place Pipe - (NEPIS)(EPA ...

5.2.12 Flexural Testing. Specimens with a geometry described in ASTM D790 were cut from the
crown, spring line, and invert of the retrieved CIPP liner for measuring the liner’s flexural strength and
flexural modulus elasticity. A total of 15 specimens were prepared and tested (five from each location).
The sides of specimens were smoothed using a grinder and a table router. The water jet cutter normally
used for specimen preparation could not be used in this case as the dimensions of the liner cutouts were
too small to hold inside the cutting board. The specimens were marked as shown in Figure 5-12. Testing
was performed using an ADMET eXpart 2611 machine (Figure 5-13). Table 5-7 lists the dimensions and
moment of inertia for each of the 15 specimens.
Using the information in Table 5-7, the following flexural stress and strain graphs for crown samples,
spring line samples, and invert samples were drawn and are shown in Figure 5-14.
Peak load, bending stresses, and deflections were obtained from the calculated data while the software
‘MtestW’ was used to calculate the peak shear stress and bending modulus of elasticity values for the
different specimens. These values are given in Table 5-8.
Figure 5-12. Flexural Test Specimens (ASTM D790): Before Test (Left) and After Test (Right)
Figure 5-13. Flexural Testing in Accordance with ASTM D790
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