PERFORMANCE OF CONCRETE MIXED WITH VOLCANIC ASH AND BUKHO STONE FRACTIONS

Abstract

To produce good-quality concrete and reduce dependence on commonly used materials, it is essential to support advanced materials that are abundantly available around the infrastructure development project. Volcanic waste materials, specifically volcanic ash as a substitute material for cement and bukho stone fractions as a local aggregate substitute, can be considered alternative concrete materials. This research aims to determine the optimal ratio of a mixture of volcanic ash and bukho stone fractions required to produce concrete with excellent compressive strength. The combination of volcanic ash and bukho stone fractions at 0%, 5%, 10%, 15%, and 20%, respectively. The compressive strength test specimens consist of cube specimens measuring 15 × 15 × 15 cm³ and cylindrical specimens with diameter and height are 15 cm and 30 cm respectively. The concrete compressive strength test was conducted at ages of 7 days, 14 days, 21 days, and 28 days, respectively. The results of the study indicated that the compressive strength of concrete produced by a mixture of 5% volcanic ash as a substitute material for cement and 5% bukho stone fractions as a substitute material for both fine and coarse aggregates was higher than that of normal concrete. A 5-10% mixture of volcanic ash and bukho stone fractions produces compressive strengths above 20 MPa for both cube and cylinder specimens. Therefore, this combination of the two materials can be considered an alternative for concrete mixes.