Pengaruh Penambahan Limbah Gypsum terhadap Nilai CBR dan Nilai Swelling Tanah Lempung

Abstract

Clay soil is a type of soil that is not suitable for use in construction work because it causes cracks or bumps on the road and lifts the foundation. This is because clay has a weak bearing capacity, is cohesive, has a high index of plasticity and shrinkage. The purpose of this study was to determine the effect of adding gypsum waste to the CBR value and the swelling value of the soil in Mulusan Village, Paliyan, Gunung Kidul. The research carried out is testing the physical properties of the soil, unsoaked CBR testing with 0, 3, and 7 days of ripening and saoked curing period of 7 days and 4 days of immersion with variations of gypsum waste 0%, 3%, 6% and 10% and Swelling Test. . The results showed that the soil included in the OH classification according to USCS, namely clay soil of medium to high plasticity, while according to AASHTO it was classified as A-7-5, namely medium to poor subgrade. Based on the original soil CBR test, the Unsoaked CBR value was 5.65% and the Soaked CBR was 1.02%. The highest increase in the Unsoaked CBR value occurred in the addition of 10% gypsum waste variation with a 3 day curing period of 44.8% and in soaked CBR the addition of 10% gypsum waste variation of 57.8%. The original soil swelling value was 5.23% and the smallest swelling value was 2.18% with the addition of 10% gypsum waste variation.