Mechanical Properties of Seawater Sea-sand Recycled Concrete in Sulfate Attack Environment

Abstract

Seawater sea-sand recycled concrete (SSRAC) is a new sort of green concrete, it has good environmental and economic benefits. In this paper, the dry-wet cycle and full immersion erosion environments is simulated. The change characteristics of mechanical properties of SSRAC under sulfate attack are studied and compared with ordinary concrete (OC) and freshwater river sand recycled concrete (RAC). The test shows that compared with immersion erosion, the dry-wet cycle significantly accelerates the deterioration rate of concrete. For the concrete in full immersion condition, the strength is still in the rising stage when the immersion corrosion to 120 d, and there is no obvious change of appearance. In dry-wet cycles, apparent damage gradually extends from the diagonal to the surrounding. The damage deterioration starts from the surface layer and gradually deepens. The prismatic compressive strength and corrosion resistance coefficient of SSRAC show the same law as OC and RAC, which increases first and then decreases. The corrosion resistance coefficient is lower than 75% at 120 cycles. The sulfate resistance of SSRAC is significantly inferior to OC and slightly greater than RAC.