Effect of Basalt Fiber on Static and Dynamic Mechanical Properties of Metakaolin-Based Cement Clay

Kun Huang,Dongdong Ma,Qinyong Ma,Melina Bosco

doi:10.1155/2020/1359163

Abstract

To investigate the effects of basalt fiber content on the mechanical properties and microstructure characteristic of metakaolin-based cement clay, the static and dynamic uniaxial compressive and splitting tensile, nuclear magnetic resonance (NMR), and scanning electron microscope (SEM) tests were performed to study the stress-strain curves, static and dynamic peak stress, pore distribution characteristic, and reinforcement mechanism. In this research, the basalt fiber with the length of 12 mm were selected and the ratios between fiber and dry soil were 0%, 0.5%, 1.0%, 1.5%, and 2.0%, respectively. The obtained results showed a noticeable difference of stress-strain curve characteristics in the static and dynamic compressive tests. A positive correlation between deformation modulus and compressive strength was found for both static and dynamic tests. The addition of basalt fiber could efficiently increase the static and dynamic strengths of metakaolin-based cement clay, and the increment 66.15% and 74.63% was observed at 1.0% basalt fiber content for static and dynamic compressive strengths, respectively, while the corresponding increment values were 93.75% and 97.62% for its splitting tensile strengths, respectively. The basalt fiber could decrease the porosity of cement clay; moreover, the reinforcement mechanism of metakaolin and basalt fiber to cement clay was analyzed based on the SEM test results.

Highlights

Fiber reinforced cement soil was a reinforced composite material with high strength and plastic deformation capacity and had been widely used in construction engineering [1,2,3]
Tran et al [7] explored the effect of cornsilk fiber on mechanical properties of cement soil, and the experimental results revealed that the addition of cornsilk fiber improved both the compressive and splitting tensile strengths of cement soil specimens
Chen [10] found that the tensile strength and plastic deformation capacity could be improved by mixing appropriate content of basalt fiber

Summary

Introduction

Fiber reinforced cement soil was a reinforced composite material with high strength and plastic deformation capacity and had been widely used in construction engineering [1,2,3]. Previous investigation results showed that the mechanical properties of cement soil could be effectively enhanced by adding an appropriate amount of fiber [4,5,6]. Chen [10] found that the tensile strength and plastic deformation capacity could be improved by mixing appropriate content of basalt fiber. It was meaningful to research the influence of basalt fiber content on dynamic mechanical properties of cement soil. Ma and Gao [20] carried out a series of dynamic compressive and tensile tests on cement soil with various basalt fiber contents. Microscopic testing methods were adopted to research the variation in the microscopic structure of internal pores and reveal the fiber reinforcement mechanism

Materials and Test Methods

Test Results

Plastic deformation stage

Reinforcement Mechanism

Conclusions