Pumice Aggregate Based Lightweight Concretes under Sulfuric Acid Environment

In this study, volcanic pumice aggregate incorporated different lightweight concretes (LWC) were investigated under a 5% sulfuric acid environment. For this purpose; OPC, OPC-FA, OPC-S, OPC-FA+S with 0%, 50%, and 100% pumice incorporations were manufactured considering cement efficiency factors for fly ash (FA) and slag (S) given in the TS13515 and EN 206-1 to evaluate the applicability of cement efficiency factors in the water and sulfuric acid environments. The visual appearance, weight change, and compressive strength tests were executed, and strength gain index and strength loss index parameters were utilized for the evaluation. The results indicated that the cement efficiency factors for the fly ash and slag were found appropriate for the pumice aggregate replacements up to 100% for the LWC incorporating only fly ash or slag. However, when the fly ash and slag were used together, the cement efficiency factors should be reduced from 0.4 to 0.35 for FA and from 0.8 to 0.75 for slag materials.