Friction Parameters of Interface between Sand and Concrete Foundation

Abstract

The objective of this research is to find the friction parameters of interface between sand and concreteby carrying out the direct shear test with the developed large-scale direct shear equipment. The developed largescaleshear device has a lower shear box size of width x length x height be 30 cm x 30 cm x 5 cm which is largeenough to simulate the real condition.

The test results showed that the interface parameters between sand and foundation concrete dependon grain size of sand. It was found that the angle of interface friction decrease when the grain size of sandincrease. And the angle of interface friction between sand and concrete foundation was decreased from 35.37 to29.31 degrees while grain size of sand increased from 0.155 mm to 4.75 mm. The efficiency, in terms of ratio ofinterface friction angle to friction angle of only sand, also showed the decreasing trend when the grain size ofsand increase. The value decreased from 0.96 to 0.80 while grain size of sand increased from 0.15 mm to 4.75mm.