Influence of flyash on the strength and swelling characteristics of bentonite

Abstract

Swelling soil like Bentonite causes many problems more for lightly loaded structures than moderately loaded structures. Through consolidation under load and changing volumetrically along with seasonal moisture variation, these problems are proved through swelling, shrinkage
and unequal settlement. It leads to damage of foundations, structural elements and architectural aspects which defeats the purpose for which the structures are erected. So to avoid these types of failures research is done and some methods have been proposed. Pre-stabilization is very
effective method in tackling expansive soil. Therefore a many laboratory experiments are conducted to ascertain host of soil engineering properties of a naturally available expansive soil before and after stabilization. Pre stabilized and post stabilized results are compared to arrive at conclusion that can thwart expansive soil problems. Such structures are requiring renovation of
foundation by under pinning. New structural shall need special techniques for control of swelling and shrinkage.
Index properties of expansive soil like Atterberg limits and shrinkage limit with and without flyash have been compared. Grain size distribution has also been determined by experiments. The swelling potential of this soil has been determined for various percentage of fly-ash. Maximum
dry density (MDD) and optimum moisture contents (OPC) have been found out by the proctor compaction test and the graphs are drawn. The strength of swelling soil is determined for soil specimens with different fly-ash concentrations through Unconfined Compression Test and the
results are compared through the graphs.
The above results of experiments are compared among them to obtain a percentage concentration of fly-ash with swelling soil which gives best results for lower value of swelling potential and higher strength.