Evaluasi Pemanfaatan Fly Ash, Abu Sekam Padi dan Abu Cangkang Sawit terhadap Workability & Kuat Tekan pada Mortar ECC dan Crumb Rubber(CR)-ECC

Abstract

Engineered Cementitious Composites (ECC) mortar is a composite material that consists of water, superplasticizer, cement, sand, and cementitious materials, but does not include gravel. To promote environmentally friendly construction, ECC utilizes waste materials from various sources, such as fly ash, rice husk ash, and palm shell ash, which possess pozzolanic properties. In addition, crumb rubber is used to enhance durability. This study was conducted using an experimental method to investigate the effects of adding different cementitious materials to ECC. A total of 16 variations were tested by adding fly ash and rice husk ash at proportions of 0%, 5%, 10%, and 15% by weight of cement. For each variation, three cube specimens (150×150×150 mm) were prepared and tested for compressive strength at 3 days of age. The ECC mortar mix that showed the optimum compressive strength was further tested with crumb rubber content ranging from 0% to 12.5%. Compressive strength tests were then conducted at 3 and 7 days. Crumb rubber was incorporated in the production of two types of CR-ECC: one using fly ash and rice husk ash, and the other using fly ash and palm shell ash. The results showed that the optimum compressive strength at 3 days was 38.67 MPa for the mix with 15% fly ash and 5% rice husk ash. Meanwhile, the optimum 7-day compressive strengths for CR-ECC were 40.43 MPa (with 15% fly ash and 5% rice husk ash) and 40.36 MPa (with 10% fly ash and 10% palm shell ash). The study also found that the compressive strength of CR-ECC decreased as the crumb rubber content increased. This decrease is attributed to the water-absorbing and compressible nature of crumb rubber, which reduces the effective volume of the ECC mortar.