Prediction of Unconfined Compression Strength for Saline-Alkaline Soils Mixed with Cement and Wheat Straw

Guoqi Xing,Wei Xuan,Bing Zhang,Changjiang Liu,Yue Zhao,Yueyue Pan

doi:10.1155/2020/2765145

Guoqi Xing, Wei Xuan + Show 4 more

Open Access

https://doi.org/10.1155/2020/2765145

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Abstract

A series of unconfined compression tests were performed to investigate the influence of wheat straws on the unconfined compression strength for saline-alkaline soils and saline-alkaline soils mixed with cement. In unconfined compression tests, 20 groups of soil specimens were prepared at five different percentages of wheat straws content (i.e., 0.0%, 0.1%, 0.15%, 0.2%, and 0.25% by weight of saline-alkaline soils) and four different percentages of cement content (i.e., 0%, 3%, 6%, and 9% by weight of saline-alkaline soils), and unconfined compression tests were carried out after 3-, 7-, 14-, 28-, and 56-day curing periods. Test results indicated that the inclusion of wheat straws within saline-alkaline soils and saline-alkaline soils mixed with cement leads to an increase in the unconfined compressive strength of specimens and also changed the brittle behavior to a more ductile one for specimens. In addition, based on the results from unconfined compression tests, a formula for predicting the unconfined compression strength of specimens related to cement content, wheat straw content, curing periods, etc., was determined, and comparing with the results from unconfined compression tests, it had higher precision in predicting the unconfined compression strength of specimens.

Highlights

Due to many advantages of synthetic fibre, such as high strength and fairly good corrosion resistance, it is widely used in the reinforcement of weak or soft soil, and some researchers had studied the mechanical properties of the soil mixed with synthetic fibre [1,2,3,4,5]
Based on the data obtained from unconfined compression tests, a formula for predicting the unconfined compression strength of salinealkaline soils mixed with cement and wheat straws is derived accurately
20 groups of specimens mixed with different cement content and wheat straw content are prepared for the unconfined compression tests (GB/T 50123-1999 [25], which is the national criterion for geotechnical tests in China)

Summary

Introduction

Due to many advantages of synthetic fibre, such as high strength and fairly good corrosion resistance, it is widely used in the reinforcement of weak or soft soil, and some researchers had studied the mechanical properties of the soil mixed with synthetic fibre [1,2,3,4,5]. In order to apply saline-alkaline soils to the geotechnical engineering, some researchers had already investigated the mechanical property of saline-alkaline soils reinforced with cement or lime [13,14,15]. Erefore, in this paper, the effect of wheat straws on the saline-alkaline soils is further studied, supplementing the data available in the literature on the behavior of fibrereinforced soil. Based on the data obtained from unconfined compression tests, a formula for predicting the unconfined compression strength of salinealkaline soils mixed with cement and wheat straws is derived accurately

Materials and Experimental Program

Results and Discussions

Conclusions