Deformation and Compressive Strength of Steel Fiber Reinforced MgO Concrete

Feifei Jiang; Zhongyang Mao; Min Deng; Dawang Li

doi:10.3390/ma12213617

Deformation and Compressive Strength of Steel Fiber Reinforced MgO Concrete

Materials (Basel). 2019 Nov 4;12(21):3617. doi: 10.3390/ma12213617.

Authors

Feifei Jiang^{1

2}, Zhongyang Mao³, Min Deng⁴, Dawang Li⁵

Affiliations

¹ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211800, China. 999620140019@just.edu.cn.
² College of Naval Architecture Civil Engineering, Jiangsu University of Science and Technology, Zhangjiagang Campus, Suzhou 215600, China. 999620140019@just.edu.cn.
³ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211800, China. mzy@njtech.edu.cn.
⁴ State Key Laboratory of Materials-Oriented Chemical Engineering, College of Materials Science and Engineering, Nanjing Tech University, Nanjing 211800, China. dengmin@njtech.edu.cn.
⁵ College of Naval Architecture Civil Engineering, Jiangsu University of Science and Technology, Zhangjiagang Campus, Suzhou 215600, China. zhjie@just.edu.cn.

Abstract

To reduce the cracking caused by shrinkage and avoid the brittle behavior of concrete, MgO expansion agent and steel fibers were used in this paper. Firstly, the effect of MgO and steel fibers on the compressive strength of concrete was compared. The results showed that the compressive strength of steel fibers reinforced concrete (SC) and steel fiber reinforced MgO concrete (SMC) was significantly improved. Compared with ordinary concrete (OC), SMC's 28 days compressive strength increased by 19.8%. Secondly, the influence of MgO and steel fibers with different contents on the self-volumetric deformation of concrete was compared through the experiment. The results showed that as a result of the hydration expansion of MgO, MC and SMC both showed obvious expansion, and their 190 days expansion was 335 μ ε and 288 μ ε , respectively. Lastly, through a scanning electron microscope (SEM) test, it was found that the constraint effect of steel fibers changed the expansion mode of MgO from outward expansion to inward extrusion, thus improving the interfacial bond strength of concrete.

Keywords: MgO expansion agent; compressive strength; concrete shrinkage; interface structure; self-volumetric deformation; steel fiber.

Abstract

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