Strengthening of Subgrade and Sub-Base of Bituminous Pavement Using RBI Grade 81

Abstract

The accumulation of a variety of compounds such as lime, cement etc., into soils has been used for centuries all through the world. The present system of stabilization is less than 40 years old, but significant advances have been made in construction events during these past four decades. The new technique of stabilization which was improved as a result of the efforts of many engineers, contractors, and researchers.RBI grade 81 is a result of these efforts. RBI Grade 81(Road Building International Grade 81) is an exclusive and resourceful product that was developed for the stabilization of a broad range of soils in a proficient, least- cost manner. The objective of this work is to determine the effectiveness of RBI Grade 81 for improvement in engineering properties of medium plasticity clayey soil.RBI Grade 81 was treated with collected soil sample at different dosages, Various samples have been made by mixing soil with 0% RBI grade 81; 2% RBI grade 81; 4% RBI grade 81; 6% RBI grade 81 and 8% RBI grade 81, method of soil replacement is opted for the preparation of samples. After studying the properties of soil sample light compaction test and California bearing ratio test was conducted under soaked and unsoaked conditions, Soaked CBR test results signify that the stabilizer can be used excellently with cohesive soils. Subsequently, unconfined compression test was done to determine the strength of clayey sample, the treated soil samples were cured for different periods 1 day, 7 day and ranging up to 28 days. From the study it was found that Soil can be stabilized with RBI grade 81 and then can be used in Sub grade and also as Sub base layer. The whole pavement can be constructed by using RBI grade 81 thus offering great cost-effectiveness. Further design of pavement and cost analysis have been done from the results obtained from various test conducted. It was concluded that RBI grade 81 is very effective stabilizer and has great impact on weaker strata and good for high volume roads.