Mechanical Properties and Microstructure of CaSO4 Whisker Reinforced Cement Mortar
来源期刊：Journal Of Wuhan University Of Technology Materials Science Edition2019年第5期
论文作者：万连建 潘锐之 XU Jun
文章页码：1170 - 1176
摘 要：Calcium sulfate whisker（CaSO4 whiskers）, a new type of microfiber material, was used in cement matrix to increase the strength of the cement based composites. Effect of CaSO4 whiskers on the mechanical properties of the resulting cement mortar was also studied. The results showed that the flexural strength and compressive strength of the mortar specimen was improved as high as 28.3% and 8.5% by incorporating 5 wt% CaSO4 whiskers. Also, the chemical composition and structural transformation of the hardened cement matrix with CaSO4 whiskers were identified by X-ray diffraction（XRD） and scanning electron microscope（SEM）. Conclusion can be drawn that CaSO4 whiskers can effectively retard the formation and restrict the coalescence of micro-crack expansion. The interaction mechanism of CaSO4 whisker on the reinforcement is mainly on three aspects: whisker pullout, crack deflection, and crack bridging. Mercury intrusion porosimetry（MIP） tests have confirmed that for 28 d cement mortar, the harmless pores increased from 9.33% to 10.62%, and the harmful pores decreased from 2.08% to 1.90%. Therefore, the whisker can optimize the pore size distribution of the resulting cement mortar.
万连建1，潘锐之2，XU Jun3
1. Department of Civil Engineering, Jianghai Polytechnic College2. Department of Civil Engineering,Yangzhou Polytechnic College3. College of Civil Engineering and Architecture, Jiangsu University of Science and Technology
摘 要：Calcium sulfate whisker（CaSO4 whiskers）, a new type of microfiber material, was used in cement matrix to increase the strength of the cement based composites. Effect of CaSO4 whiskers on the mechanical properties of the resulting cement mortar was also studied. The results showed that the flexural strength and compressive strength of the mortar specimen was improved as high as 28.3% and 8.5% by incorporating 5 wt% CaSO4 whiskers. Also, the chemical composition and structural transformation of the hardened cement matrix with CaSO4 whiskers were identified by X-ray diffraction（XRD） and scanning electron microscope（SEM）. Conclusion can be drawn that CaSO4 whiskers can effectively retard the formation and restrict the coalescence of micro-crack expansion. The interaction mechanism of CaSO4 whisker on the reinforcement is mainly on three aspects: whisker pullout, crack deflection, and crack bridging. Mercury intrusion porosimetry（MIP） tests have confirmed that for 28 d cement mortar, the harmless pores increased from 9.33% to 10.62%, and the harmful pores decreased from 2.08% to 1.90%. Therefore, the whisker can optimize the pore size distribution of the resulting cement mortar.
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