Waste tyres have been an increasing problem every year due to the increase in vehicle sales. In Indonesia, more than 50 million waste tyres were generated every year. However, materials in waste tyre such as textile and steel fibers, actually, can be used to improve the mechanical properties of the concrete. Recently, some researchers have been devoted to the utilization of steel fibers extracted from the waste tyre (SFEFWT) on the concrete. This study focuses on the investigation of SFEFWT effect on the concrete containing palm oil fuel ash (POFA). Steel fibers were extracted from waste tyres by manually cutting process and being cut to 1 inch (25.4 mm) length. A number of cylindrical and beam specimens of concrete containing 15% palm oil fuel ash by being partially replaced the weight of cement, with addition 0.25%, 0.50%, 0.75% and 1% SFEFWT were cast and tested. The mechanical properties such as compressive, tensile and flexural strengths at the age of 28 days are studied for having prepared the concrete. The results show that the addition of SFEFWT on the concrete containing POFA improves the concrete strengths, particularly the tensile and flexural strengths. The more percentage of SFEFWT content on the POFA concrete results in the higher increase in tensile and flexural strengths. In addition, the presence of SFEFWT contributes to give higher bonding on concrete to control the crack opening on the POFA concrete.
