Cyclic behavior and strength evaluation of RC columns with dune sand

Abstract

Dune sand (DS) has potential for producing concrete and being used in massive construction projects where commonly used natural sand is facing a shortage while DS is available in abundance. The cyclic behavior of reinforced concrete (RC) columns with DS was experimentally investigated. The influence of DS replacement ratio on the concrete strength and workability was investigated, and the DS replacement ratio as high as 60% for the DS-RC columns was mainly considered. Thirteen square specimens, with a width of 300 mm, were tested under cyclic lateral loading combined with an axial compressive load. Then, the effects of the shear span to effective depth ratio, the DS replacement ratio, the axial compression ratio, and the stirrup ratio on the seismic behavior and strength of DS-RC columns were studied. Test results showed that the shear span dominated failure modes of the specimens and then affected the lateral load capacity, deformation capacity, and ductility capacity. The DS replacement ratio in the range between 20% and 40% moderately improved the seismic behavior of DS-RC columns. The axial compression ratio and the stirrup ratio affected the shear resistance, deformation capacity, and ductility capacity. The design methods for predicting flexural strength and the shear strength of DS-RC columns and design implications were proposed.