Density, load, and fly ash effect on stabilization of high plasticity soil with lime

Abstract

The reuse of recycling materials or industrial waste materials with aims to reduce environmental pollution strongly supports the concept of green building. Fly Ash is the result of the combustion of pulverized system coal at the PLTU Tenayan and is no longer included in the B3 waste category. The use of fly ash as a building material, mine restoration, and roads in this decade, is to replace cement or lime. The fly ash composition is mixed with lime for the sub-base and will be applied on high-plasticity soils. A fix-mixture of soil and lime 5%, mixed with fly ash up to 30% of the mixture. The samples test was made at optimum moisture content, with density values around the maximum dry density (MDD) i.e. under or above MDD. Consolidated testing was performed with and without curing. Changes in load are represented by the load increment ratio (LIR). The selected LIR values were 1.0; 1,5; and 2.0. The results showed that the higher of density, the volume of the void is lower. The soil compression index value is the same for all density values if the soil structure has not been destroyed. or fatigued yet. In samples with crushed/broken soil structures, the value of the compressibility index decreased sharply. Curing successfully decreased the void ratio and compressibility of the soil. The strength of fly ash will decrease when reacting with water, so if the soil is burdened, the void ratio decreases drastically. The formation of strong molecular bonds between fly ash and lime takes time. So, the compressibility value of the sample by curing for 28 days is better than without curing. The composition levels between fly ash and lime also affect the compressibility index of the mixture. The optimum combination occurs in samples with a fly ash content of 25%.