The effect of cement stabilization on the strength of the Bawen’s siltstone

¹ Ph.D Student, Department of Civil Engineering, Diponegoro University, Semarang, Indonesia
² Department of Civil Engineering, Diponegoro University, Semarang, Indonesia
³ Department of Civil Engineering, Universitas Muhammadiyah Yogyakarta, Yogyakarta, Indonesia

^* Corresponding author: muntohar@umy.ac.id

Abstract

Siltstones are predominantly found along the Bawen toll-road. Siltstone is degradable soil due to weather session. The soil is susceptible to the drying and wetting and the changes in moisture content. Thus, Siltstone is problematic soils in its bearing capacity when served as a subgrade or subbase. The main objective of this study was to investigate the effect of cement stabilization on the strength of Siltstone. The primary laboratory test to evaluate the strength was Unconfined Compression Strength (UCS) and California Bearing Ratio (CBR). The cement content was varied from 2 to 12 per cent by weight of the dry soil. The soils were collected from the Ungaran - Bawen toll road. The specimens were tested after seven days of moist-curing in controlled temperature room of 25°C. The CBR test was performed after soaking under water for four days to observe the swelling. The results show that the mudstones were less swelling after soaking. Cement-stabilized siltstone increased the CBR value and the UCS significantly. The addition of optimum cement content for siltstone stabilization was about 7 to 10 per cent.