Effect of cement content on the behavior of dune sand-cement admixtures

The dune sands of the coast of Rio Grande do Norte State, northeastern Brazil, have serious engineering problems, namely low bearing capacity for shallow foundations and are not suitable as material for sub-base and road base. The use of this material in engineering practice needs improvement of their geotechnical properties. This paper investigates the effect of adding Portland cement to stabilize dune sand from the region of Natal, Brazil. Undrained triaxial tests were carried out to evaluate the effect of cement content on the geotechnical behaviour of dune sand-cement admixtures. Tests with admixtures with cement contents of 2.5, 5 and 10% of the dry mass of soil were carried out. Results showed that soil cohesion increased with increasing cement content. The friction angle of the admixtures was lower than that of the uncemented sand for cement content of 2.5 and 5% while It was larger than that of the uncemented sand for cement content of 10%.