Influence of rubber content and compaction energy on the permeability and compressive strength of coarse-grained soil

Abstract

This research focuses on studying and improving the properties of coarse-grained soil by mixing it with Preservative natural rubber latex to reduce water seepage in coarse-grained soils. Excavated ponds in areas with coarse-grained soil experience high water leakage, preventing them from retaining water for use during the dry season. Rubber latex content was used at ratios of 0%, 1%, 2%, and 3% by weight of dry soil. The samples were compacted using standard compaction energies of 25%, 50%, 75%, and 100% for each ratio, then cured in open air for 3 days. The samples were subsequently tested for permeability coefficient under pressure, using a criterion of a permeability coefficient (k₂₀) equal to 0.5 cm/hr, and for compressive strength. The results showed that, in soil without rubber latex improvement, the permeability coefficient decreased as compaction energy increased. In soils improved with rubber latex, the permeability coefficient decreased at the same compaction energy as the rubber latex content increased. The prediction for the amount of rubber latex required to improve soil properties to meet the evaluation criteria indicated that compaction energies of 25%, 50%, 75%, and 100% needed at least 2.85%, 2.57%, 2.39%, and 2.15% rubber latex content, respectively. The sample improved with 1% rubber latex at 100% compaction energy had the highest compressive strength value of 1.51 ksc. These findings can be applied by using the improved soil as lining material for the bottoms and walls of ponds, which will enhance water retention efficiency for farmers in coarse-grained soil areas outside irrigation zones.