Effect of RBI Grade 81 on strength characteristics of clayey subgrade

Shiva Prashanth Kumar Kodicherla,Darga Kumar Nandyala

doi:10.1186/s40703-017-0061-z

Shiva Prashanth Kumar Kodicherla, Darga Kumar Nandyala

Open Access

https://doi.org/10.1186/s40703-017-0061-z

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Abstract

The present study deals with the effect of Road Building International Grade 81 (RBI Grade 81) on strength characteristics of the clayey subgrade. A wide range of tests was conducted on various percentages of RBI Grade 81 subgrade mixtures such as Atterberg limits, compaction characteristics, California Bearing Ratio (CBR) and Unconfined Compression Strength tests (UCS). It can be noticed that the CBR of clayey subgrade has increased significantly with the addition of RBI Grade 81. Similarly, the maximum dry density (MDD) has decreased and the optimum moisture content (OMC) has increased with RBI Grade 81 addition to subgrade. The strength of clay subgrade at 8% of RBI Grade 81 has improved 3–3.5 times as compared to the natural clayey subgrade. Overall, it can be concluded that RBI Grade 81 is suggested as a potential stabilizing agent especially for clayey subgrades.

Highlights

Clayey subgrade soils are known as troublesome soils in causing damages especially to the buildings and highway pavements
Liquid limit and plastic limit Liquid limit and plastic limits are well known as Atterberg limits and are very useful to assess the consistency of fine-grained soils
In view of the expected improvements in the soil subgrade, the locally available clay soil stabilized with RBI Grade 81 significantly improved the geotechnical properties of the subgrade

Summary

Introduction

Clayey subgrade soils are known as troublesome soils in causing damages especially to the buildings and highway pavements. One of the trending stabilizers which have been considered by the engineers is Road Building International Grade 81 (RBI Grade 81) It is a natural inorganic soil-stabilizer that can modify the properties of soil to strengthen the subgrade of highway pavements. If the nature of the soil changes for different depths, most of the methods for stabilization cannot be used but it has a wide range of response spectrum being an eco-friendly material that has many advantages over the other stabilizers used It can reduce 30–40% of the construction cost, drastically increases the strength of the pavements, and reduce transport and earth moving costs by 60%. Apart from the previous investigations it is proven that unconfined compressive strength (UCS); soaked California Bearing Ratio (CBR) increases in addition of RBI Grade 81 It is noticed from the literature that it is suitable to improve the performance of the soft soils acting as a good stabilizer.

Findings

Discussion of results

Conclusions