Comparative study on Expansive Soil Stabilization using Scoria (red ash) and Stone Dust to Improve the Engineering Properties of Subgrade Soil: A Case of Ginchi Town

Abstract

Expansive soils are characterized by very low bearing capacity high compressibility, low permeability and high-volume change under changing moisture conditions. They tend to lose strength further upon wetting and other physical disturbances. These soils are especially troublesome as pavement sub grades and unsuitable for construction of embankments, buildings or other light structures in their natural state The purpose of this study is to assess the geotechnical features of expansive soils blended with scoria (red ash) and stone dust, as well as compare the improvement of scoria (red ash) and stone dust. The objective of this study was to compering the improvements achieved on the engineering properties of subgrade soil for Ginchi town due to scoria (red ash) and stone dust. In the town, three soil samples were taken from distinct borrow pits. Scoria (red ash) was taken from the Sankale mountain query site, while stone dust was obtained from the ERA query site (crusher). Laboratory tests were conducted to determine moisture content, specific gravity, and grain size analysis, Atterberg limits, proctor test, free swell test, California Bearing Ratio and CBR swell tests. The test procedures were based on AASHTO laboratory test standards. The test results show that the sub grade soils are A-7-5 as per AASHTO soil classification system and CH as per USCS.As far as the engineering properties of natural subgrade soils were studied the three soils were Expansive clay soils. The engineering properties of the three soils are nearly identical. Ginchi technical college's sample was black, Ginchi police station's sample was black, and Ginchi auragodan's sample was dark gray. By weight, 10, 20, 30, 40, 50, and 60% of scoria (red ash) and stone dust were used to stabilize the soil samples collected to compering the effect of SD and SC. Increased ratios of scoria (red ash) improved subgrade soil characteristics. And the increments of SD improve the subgrade soil characterstics. But stone dust is more improve the engineering properties of expansive soil of Ginchi town. The improvement of sub grade soil properties were increased with increased ratios of stone dust. The maximum improvements on engineering properties were observed on index properties and minimum improvements were on strength parameter for SC .and the maximum improvements for both on index properties and strength parameter for SD. when compere to SC It was observed that stone dust was better than scoria (red ash) in improving sub grade soil properties. However, using stone dust is not economical due to its availability and current market cost compared to cost and availability of scoria (red ash). The findings of this study reveal that comparing scoria (red ash) and stone dust stabilized soils for the improvement of subgrade soil. When mixed in the right proportions, meet all of the standards for subgrade soils. Further detailed examinations, including chemical and mineralogical analyses of the stabilized soils, will be essential for the practical use of the stabilized soils.