Figure 44. Test temperature needed for 50 years life.
Flexural test samples of 0.25- 0.5-in. cross section and 5-in. length cut from a PVC sheet
pile sample from one of the suppliers were subjected to a four-point bending test as per ASTM
D790 at room temperature. Figures 45 and 46 show the testing. Note that the PVC material can
undergo severe bending without any fracture and failure. The maximum (peak) value was
considered the yield strength, and these values are shown by bar diagrams for each exposure type
in Figure 47. Figure 48 gives the plot of the average yield stress values; again no significant
reduction was noticed with the length of exposure.
Figure 45. Four-point flexural bending test.
Figure 46. Excessive deflection without any
fracture because of lower modulus of the