Subgrade Stabilization with Ca (OH)2 Lime to Improve the Physical and Mechanical Properties of Soil (Case Study: The National Road Trengguli – Bts. Kab. Demak/Kudus)

Abstract

Road damage on The National Road Trengguli - Bts. Kab. Demak/Kudus in the form of cracks and collapses, the contributing factors are soft subgrade conditions and irrigations on both sides of the road. Chemical stabilization with Ca(OH)2 lime can improve the physical and mechanical properties of the soil. This research uses the addition of lime with variations of 2%, 4%, 6%, 7%, 8%, and 10% of the dry weight of the soil. Based on the standard proctor test results, the optimum mixture of 6% lime was obtained with a value of γ_dmax = 1.459 gr/cm³ and W_opt = 28.052%. Furthermore, the original soil and 6% lime mixture were tested: sieve and hydrometer analysis, Atterberg limits, standard proctor compaction, unconfined compressive strength (UCS), laboratory CBR (soaked) and 1 cycle drying - wetting testing. At 6% lime for UCS and CBR testing, 0, 7 and 14 days of curing were conducted. The results of research on the initial soil and after 6% lime stabilization, namely the soil classification based on USCS originally included in CH, namely non-organic loamy soil with high plasticity or fat clays to SM, namely silty sand and based on AASHTO originally included in A-7-6 clay soil to A-7-5 clay soil, from PI = 43.232% to PI = 16.213%, from CBR = 0.917% to CBR with 0, 7, and 14 days of curing are 11.463%, 14.266%, and 19.408%, from qu = 0.967 kg/cm² to qu with 0, 7, and 14 days of curing are 2.973 kg/cm², 9.546 kg/cm² and 12.206 kg/cm². After 1 cycle drying - wetting test, there is a decrease in qu value, namely in the initial soil of 93.004% and 6% lime stabilized soil of 73.040%.