The Effect of Adding Gypsum and Lime on Lightweight Interlock Bricks with Merapi Sand as Fine Agregat

Abstract

Abstract Lightweight materials will reduce the earthquake forces received by the structure. Interlock lightweight brick is a new innovation in the building industry that functions as wall material. Utilization of local materials in Central Java-Yogyakarta, namely Merapi sand, needs to be developed to maximize its potential utilization as an aggregate of lightweight interlock brick. In many research, lime and gypsum as additives have been shown to improve the quality of concrete. This study aims to determine the characteristics of the addition of gypsum and lime as an added material for lightweight interlock bricks with fine aggregate of Merapi sand. The standard of test object and the test refers to SNI 8640-2018. The results showed that in dry weight all the mixed variations were categorized in the 900 kg/m3 and 1100 kg/m3 classes. All variations also complied with water absorption requirements in SNI 8640-2018, but only variations of 2.5% gypsum addition and 5% lime addition meet the compressive strength requirements. This mixture has the highest average of compressive strength value compared to other mixtures. Based on SNI 8640-2018 lightweight interlock bricks with the addition of 2.5% gypsum and 5% lime can be used as wall bricks.