Pore Structure Fractal Characteristics of PVA Fiber Concrete under Salt Erosion and Freeze-Thaw Cycle

Abstract

Abstract: To study the effect of polyvinyl alcohol (PVA) fibers on pore structure of concrete and its connection with frost resistance performance, the microscopic pore structure of PVA fiber concrete under the action of freeze-thaw cycle was tested by nuclear magnetic resonance (NMR) technology, the NMR T₂ spectrum and the change rule of pore distribution were analysized, and the pore fractal characteristics were explored based on fractal theory to reveal the relationship between the pore structure of PVA fiber concrete under the action of freeze-thaw cycle and fractal dimension. The relationship between pore structure and fractal dimension of PVA fiber concrete under the freeze-thaw cycle was revealed. The results show that PVA fiber concrete shows better frost resistance in the pre-freeze-thaw cycle period. The number and percentage of medium pores (100＜r≤1 000 nm) and large pores (r＞1 000 nm) increase, which weaken the frost resistance of PVA fiber concrete. The PVA fiber concrete has a certain fractal characteristic, and the fractal dimension D_max increases before five times freeze-thaw cycles and decreases with the increase of freeze-thaw cycles times.

Key words: freeze-thaw cycle, PVA fiber concrete, pore structure, nuclear magnetic resonance, fractal dimension, frost resistance

CLC Number:

TB332

WU Hao, XUE Weipei, WANG Zhongjian. Pore Structure Fractal Characteristics of PVA Fiber Concrete under Salt Erosion and Freeze-Thaw Cycle[J]. BULLETIN OF THE CHINESE CERAMIC SOCIETY, 2024, 43(5): 1859-1866.

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