The durability of lightweight concrete against 5% hydrochloric acid solution with various size of expanded polystyrene

The use of foam and expanded polystyrene (EPS) in concrete can significantly reduce the density of concrete. The composition of lightweight concrete consists of Portland composite cement, expanded polystyrene, water, and foam. The ratio of the composition used is 1:2.75 for cement and aggregate, 1:40 for foaming agent and water, and 0.485 for W/C. The expanded polystyrene sizes used are 1 mm, 2 mm, and 3 mm. All specimens were cured for 28 days. The concrete test results at 28 days provided compressive strengths of 6.64 MPa, 5.53 MPa, 3.73 MPa, and 13.58 MPa, as well as density of 886 kg/m3, 830 kg/m3, 782 kg/m3, and 1,870 kg/m3 for mixtures of LWC-1, LWC-2, LWC-3, and Normal Mortar. The aim of this research was the performance of lightweight concrete with EPS by determining the durability, density, and the compressive strength using a 5% hydrochloric acid (HCl) solution. In the previous studies, the EPS had been heated before mixed. In this study, the EPS had not been heated and directly used in the mixing process. The lightweight concrete with EPS was very potential to reduce structure mass then resulted in a lower earthquake loads on the structures. There were three different conditions of treatment for the specimens that were open room, completely immersing in HCl 5%, and cyclic. The durability of lightweight concrete was determined during 28 and 56 days of immersion in HCl solution to obtain the results of reduced compressive strength and density. The condition III showed the most significant reduction in density and compressive strength at the age of 56 days immersion. The normal mortar has the best durability when compared to all LWCs, with a reduction of density and compressive strength of 14.08% and 32.88%, while the LWC-1 showed the best durability with a reduction in density and compressive strength of 18.41% and 35.44%.