Study on Strength Behavior of Organic Soil Stabilized with Fly Ash.

Bayshakhi Deb Nath,Md Keramat Ali Molla,Grytan Sarkar

doi:10.1155/2017/5786541

Bayshakhi Deb Nath, Md Keramat Ali Molla + Show 1 more

Open Access

https://doi.org/10.1155/2017/5786541

Copy DOI

Abstract

The aim of this study is to investigate the effect of fly ash on the consistency, compactness, acidic properties, and strength of organic soil. The presence of organic content in the soil has detrimental impacts on the physical and strength behavior of soil. To investigate the effectiveness of fly ash in the stabilization of organic soil, two types of fly ashes (Type I and Type II) at different percentages were used. It is found that fly ash significantly reduces the plasticity index of the organic soil, whereas the liquid and plastic limits increase. The dry density of the fly ash-soil mixture increases significantly, while the water requirement reduces due to the addition of fly ash. The increase of dry density compromises higher strength. The increase of qu with the increase of fly ash content is mainly due to the pozzolanic reaction of fly ash, although the reduction in water content results from the addition of dry fly ash solid. Moreover, Type I fly ash contributes a higher value of qu compared to Type II fly ash. This is attributed to the characteristics of fly ash including CaO and CaO/SiO2 ratio.

Highlights

Soil is one of the most important and primary media for any construction work
It is clear from the figure that the final qu achieved varies depending on the organic soil and the fly ash. This is in contrast to the findings reported for inorganic soils stabilized with different fly ashes by Edil et al [29], for which final strengths were comparable, strength factors varied
(ii) Both values of liquid limit and plastic limit increase and the plasticity index decreases with increasing percentages of both types of fly ash content

Summary

Introduction

The strength and durability of any structure depends on the strength properties of soil It has been found from several studies that, due to the detrimental characteristics of organic soil, the shear strength and bearing capacity of this soil are very low, while the compressibility is very high. Subgrades of roadways are generally constructed by replacing the underneath organic soil with granular soil named “cut and replace” or preloading to improve the engineering properties of soil, which requires a huge investment cost and effort. This cost of using granular soil can be minimized by blending and mixing the existing soil with a cementing admixture, known as chemical stabilization process. Lime, rice husk ash, and fly ash are widely used and have attracted the attention of researchers because of their low cost and high pozzolanic action [2,3,4,5,6,7]

Objectives

Methods

Conclusion