Improvement of Soft Clay Soil Using Different Types of Additives

Abstract

This study deals with the evaluation of the stabilization of several samples of soft soil with some chemical and physical additives. The intention is to amend the weak properties of these soils summarized in low bearing capacity and high settlement. The used stabilizers are quicklime, class F fly ash activated by cement, rock powder, crushed waste concrete, and tire crumb rubber. The paper investigated the effects of these stabilizers by unconfined compression test that considers very effective geotechnical test for measuring the ability of soils to bear structures constructed on them especially when used additives. This test was carried out on three samples of soils. They were classified by (UCSC) as (CL) soft soils. They were also classified by (AASHTO) as (A-7-6), (A-6), and (A-6) are rated as fair to poor subgrades in (AASHTO). The results of (UCS) test for each of the five additives used were compared according to the responding of each soil samples used. The (UCS) test was conducted in this study on sixty samples of soils before and after treatment and under the basics of the Proctor compaction test at optimum moisture content and maximum dry density. The results showed that the rock powder was the most suitable stabilizer that gave best results of improvement reached to 900% at 25% percent by dry weight of soil, crushed waste concrete came after it that gave treatment 683% at 15%, class F fly ash activated by cement followed the two formers which increased strength 533% at 15%, quicklime after that in an amendment 517% at 9% and finally tire crumb rubber that stabilized the soil 500% at 4%. In the literature, these materials founded to be very efficient in the stabilization of soils in their physical and chemical properties like increasing bearing capacity and reducing settlement of soil.