Abstract:
The aim of this study was to investigate the shear and flexural strengths of clay-soil cement mixed with different portions of sand. The testing was conducted in the laboratory.
The soil sample was soft Bangkok clay deposit and the sand was Kanchanaburi sand deposit. The particle size of sand was the one passing through sieve No. 4 but retained on sieve No. 10. The cement used was a Portland Cement Type 1. Firstly, the clay sample was mixed with sand of 0, 20 and 40% by dry weight of clay. Then the aggregate of clay and sand was mixed with cement of 10, 15 and 20% by dry weight. The water content of the aggregate was adjusted to approximately 5% above its liquid limit.
After that, the second aggregate was put into 2 molds: 1) a cylinder mold with a diameter of 3.5 cm X 7 cm for the unconfined compression test and the CU test, and 2) a beam mold with the size of 7.57.535 cm3 for the third point loading test. After 28 curing days, the prepared specimens were tested. It was found that the more amount of sand, the higher unconfined compressive strength (qu), angle of internal friction and modulus of rupture. Finally, the correlations of the 3 testing results were presented.