Effect of Natural Resin on Strength Parameters of Sandy Soil

Abstract

Nowadays, strength characteristics of soils have more importance due to increasing building loads. In some projects, geotechnical properties of the soils should be improved. Geotechnical engineers generally use waste materials to improve soil properties but most of these materials have toxic substances such as heavy metal slags, fly ash, silica fume and industrial resins. In this study, the effects of the addition of a plant gum, named as astragalus, grown commonly in Central and East Anatolia, Iran, Iraq, Turkmenistan and Transcaucasia, on the stability and strength parameters of cohessionless soil were investigated. Astragalus is a pure natural and environmental friendly material. Ground water directly affected by soil additives which used for soil improvement. In this investigation, properties of a cohessionless soil were stabilized by using astragalus. In order to find out which rate of the additive caused maximum strength parameters of the soil samples which prepared by using four different replacement amounts of 0%, 3%, 5% and 10% by weight of soil. Maximum dry densities and optimum moisture contents were determined for each mixture. Strength parameters of each mixture were also determined. According to experimental study, adding 1% of astragalus content is convenient for sandy soil when considered strength parameters and economical respect of additive material. I. I NTRODUCTION Human beings use soil as building and foundation material to build homes and roads through the ages. Geotechnical properties of an soil can be improved in two ways: compaction and mixing with additive material such as lime, cement, fly ash, natural materials etc. In this paper, geotechnical properties of an embankment soil were improved. The soil was taken from a commercial sand pit in Elazig City. Effects of a plant gum, named as astragalus, on the strength parameters of the sandy soil were studied. Geotechnical properties of the sandy soil were determined. Maximum dry density and optimum moisture content of the sandy soil also found out. Samples were prepared by using four different replacement amounts of 0%, 1%, 3%, 5% and 10% by weight of soil. All samples were prepared at optimum moisture content. Shear box tests were conducted on these samples. The existing soil at a construction site cannot always be totally suitable for supporting structures. For this reason