Investigasi Workability dan Kuat Tekan pada Mortar dan Bio Serat- ECC yang Berbasis Fly Ash dan Abu Cangkang Sawit

Abstract

Concrete is a fundamental composite material in the modern construction industry, formed through a proportional mixture of cement as a hydraulic binder, fine aggregate (sand), coarse aggregate (gravel or crushed stone), and water. Despite its widespread use, conventional concrete has limitations, particularly in terms of ductility and crack resistance. In response to these shortcomings, Engineered Cementitious Composites (ECC) have emerged as an innovative material with high deformation capacity and superior crack resistance. This research aims to explore the potential utilization of waste materials, namely fly ash and palm kernel shell ash (ACS), in the production of ECC mortar. Furthermore, this study replaces the Polyvinyl Alcohol (PVA) fibers commonly used in ECC with natural fibers, specifically bamboo and rattan fibers, considering their abundant availability in Indonesia, thus resulting in the concept of Bio-fiber ECC.The research methodology comprises two main stages. First, the optimization of ECC mortar mixtures was conducted using fly ash and ACS with varying percentages of 0%, 5%, 10%, and 15% by weight of cement. Compressive strength testing was performed on 15 cm x 15 cm x 15 cm cubes at 3 days of age, and the optimum compressive strength of the ECC mortar was achieved at 37.5 MPa. Second, the optimized ECC mortar mixture was then modified by the addition of bamboo and rattan fibers with varying volume fractions of 0%, 1%, 1.5%, and 2%, and fiber lengths of 0.5 cm and 1 cm with a diameter of 1 mm. Compressive strength testing was again performed at 3 and 7 days of age. The results indicate that the addition of bio-fibers improves the compressive strength. The optimum compressive strength of Bio-fiber ECC with bamboo fibers was recorded at 38.39 MPa at 3 days and 42.58 MPa at 7 days, using bamboo fibers with a length of 0.5 cm and a volume fraction of 1%. Meanwhile, the optimum compressive strength of Bio-fiber ECC with rattan fibers reached 34.23 MPa at 3 days and 38.26 MPa at 7 days, also with the addition of rattan fibers with a length of 0.5 cm and a volume fraction of 1%. This research indicates the significant potential of utilizing industrial waste and local natural fibers as promising alternative materials in the development of more sustainable and economical ECC in Indonesia.

Keywords: Engineered cementitious composite, Mortar ECC, Bio fiber ECC, fly ash, palm kernel shell ash, compressive strength