Splitting Tensile Strength of Cement Soil Reinforced with Basalt Fibers.

Shengnian Wang,Qinpei Xue,Peng Zhang,Fangyuan Chen

doi:10.3390/ma13143110

Abstract

Due to low splitting tensile strength, cement soil is more likely to experience dry shrinkage and cracking in practical engineering. In this study, the mixing procedure of the cement soil reinforced with basalt fibers was investigated; the influences of cement content, curing time, basalt fiber content and length on the splitting tensile strength of the cement soil reinforced with basalt fibers were studied; and the correlation of the splitting tensile strength vs. the compressive strength of the cement soil reinforced with basalt fibers was discussed. The contribution of basalt fibers on performance improvement of the cement soil was also addressed based on the microstructural analysis and the toughening mechanism exposition. Results indicate that the best mixing method for the cement soil reinforced with basalt fibers is to mix the muddy silty clay with basalt fibers first, then with cement slurry. The increase of cement content and curing time can improve the splitting tensile strength of the cement soil effectively. The splitting tensile strength of the cement soil increases first and then decreases with the content and length of basalt fibers. The optimal content and length of basalt fibers for the cement soil are 0.4% and 12 mm, respectively. The relationship between the splitting tensile strength and the compressive strength of the cement soil reinforced with basalt fibers can be described as a linear relationship with the correlation coefficient of 0.245 and the determination coefficient of 0.990. The contribution of basalt fibers on the toughening mechanisms of cement soil shows that the fiber-matrix interaction would be the dominant effect to control the tensile strength of the soil-cement-fiber composites. The results of this study can provide a reference for the design and application of cement soil reinforced with basalt fibers in actual engineering.

Highlights

Due to its flexible reinforcement style, great water-sealing effect, little construction disturbance, and low cost, cement soil has been widely used in the reinforcement of soft soil foundations, core walls of earth-rockfill dams, and other projects [1]
The splitting tensile strength of the samples obtained from the peak load of the diametric
The splitting tensile strength of the samples obtained from the peak load of the diametric compression test are shown in Table 4, in which Cv is the variation coefficient

Summary

Introduction

Due to its flexible reinforcement style, great water-sealing effect, little construction disturbance, and low cost, cement soil has been widely used in the reinforcement of soft soil foundations, core walls of earth-rockfill dams, and other projects [1]. The low tensile strength of the cement soil always leads to the cracking of the supporting structure, and hydraulic fracturing failure in the core wall of the earth-rockfill dam. The ultimate bearing capacity and the strain corresponding to the failure load of the cement soil would be much higher than the plain soil when the cement content continued to increase. It is not the case that greater cement content will lead to better ultimate bearing capacity of the cement soil. When the cement content is exorbitantly high, the excessive volume shrinkage caused by evaporation of water during the hardening process

Methods

Discussion

Conclusion