COMPARISON OF MOUNTAIN STONE AND RIVER STONE WITH THE SAME MIX ON THE COMPRESSIVE STRENGTH OF CONCRETE

Abstract

The utilization of locally available aggregates is an important consideration in concrete production, particularly in regions where the availability and transportation of conventional river aggregates may affect construction efficiency. This study aims to evaluate the compressive strength performance of concrete incorporating Kepahiang mountain stone as an alternative coarse aggregate in comparison with Sungai Lais river stone. The experimental investigation was conducted using concrete mixtures with identical proportions and a water-to-cement ratio of 0.45, designed to achieve a target strength of K-300. A total of 12 cylindrical specimens were prepared, consisting of six specimens for each type of coarse aggregate, and compressive strength was evaluated after 14 days of curing. The physical and mechanical properties of the aggregates were also examined, including specific gravity, water absorption, and abrasion resistance. The results indicate that the concrete containing Sungai Lais river stone achieved a higher average compressive strength of 325.030 kg/cm², compared with 310.738 kg/cm² for the concrete containing Kepahiang mountain stone. The characteristic compressive strengths were 311.621 kg/cm² and 300.789 kg/cm², respectively, resulting in a difference of 10.832 kg/cm² or approximately 3.48%. Despite this difference, both mixtures achieved the targeted K-300 concrete strength. Furthermore, the average mass of the mountain-stone concrete specimens was 12.11 kg, lower than the 12.75 kg recorded for the river-stone concrete. These findings indicate that Kepahiang mountain stone has potential as a locally sourced alternative coarse aggregate for concrete production, particularly under mixture conditions comparable to those investigated in this study. Further research involving different curing ages, water-to-cement ratios, aggregate gradations, and durability parameters is recommended to establish its broader applicability in construction.