Effect of magnesium sulphate and sulphuric acid attack on limestone calcined clay cement concrete

Abstract

The production of cement results in significant CO2 emissions into the atmosphere, contributing to the problem of global warming. This problem can be partially solved by using ground calcined clay-limestone (GCCL) cement concrete. The paper describes an experimental study of the performance of GCCL cement concrete in a sulphate and acidic environment. The GCCL concrete is made of using mixture of clinkers: ground calcined clay: low grade of limestone: gypsum in proportion as 50:30:15:5. Weight loss, compressive strength, and microstructure of GCCL concrete were investigated and compared with Ordinary Portland Cement (OPC) concrete. The microstructures of GCCL and OPC concrete has been observed using scanning electron microscope (SEM) images. GCCL concrete shows better strength properties than concrete prepared with OPC. At 0.5 w/c ratio, 28 days, 56 days, and 90 days GCCL concrete exhibited strength loss was 3.36%, 6.16%, and 12.33 % respectively after immersion in magnesium sulphate solution while strength loss was 9.32%, 17.44%, and 19.84% respectively observed after immersion in H2SO4 solution. Similarly, weight loss of GCCL concrete exhibited higher resistance to sulphate and acid attack than as compared to OPC concrete.