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Pore Structure Evolution and Resistance to Water Penetration of Slag RAC Based on Grey Correlation Analysis
SHI Wen, XIAO Jian, DU Ting, GAN Yi-dong
Journal of Changjiang River Scientific Research Institute ›› 2026, Vol. 43 ›› Issue (4) : 196-200.
PDF(865 KB)
PDF(865 KB)
Pore Structure Evolution and Resistance to Water Penetration of Slag RAC Based on Grey Correlation Analysis
[Objective] This paper aims to investigate the influence of slag content on the resistance to water penetration and pore structure of recycled aggregate concrete(RAC), to reveal the relationship between resistance to water penetration and pore structure, and to provide a reference for its durability research and engineering application. [Methods] The slag content was designed to replace cement at proportions of 0%, 10%, 15%, 20%, 25%, and 30%, respectively. Six groups of C30 RAC with slag were prepared according to these proportions. Tests on water absorption and water penetration height with different slag contents were conducted, as well as microscopic pore structure tests using low-field nuclear magnetic resonance. Based on the results of the water penetration tests and microscopic tests on RAC, the relative permeability coefficient was taken as the reference sequence, and the proportions of different pore types as the comparison sequence, Then,the grey correlation analysis method was used to analyze the relationship between the resistance to water penetration and the pore structure of RAC. [Results] The results showed that with increasing slag content, the water penetration height and relative permeability coefficient of RAC both decreased. Compared with the test group without slag, the water penetration height and relative permeability coefficient of RAC test group with 30% slag content decreased by 26.01% and 61.12%, respectively, indicating that the resistance to water penetration of RAC was significantly enhanced. Based on the experimental data, a relationship model between the relative permeability coefficient of RAC and the slag content was constructed, and the fitting degree of the model reached 98.97%. Furthermore, the results of microscopic pore structure tests using low-field nuclear magnetic resonance showed that the porosity of RAC also decreased with increasing slag content. This indicated that slag could refine and reduce the internal pores of RAC, increase its compactness, and thereby enhance its resistance to water penetration. Grey relational analysis showed that incorporating slag led to significant changes in the pore structure of RAC. Specifically, slag reduced the proportion of intermediate pores and large pores in RAC, leading to a decrease in overall porosity and a more compact microstructure, which in turn enhanced its resistance to water penetration. [Conclusion] Incorporating an appropriate amount of slag can improve the resistance to water penetration of RAC, providing a reference for its engineering application.
RAC with slag / resistance to water penetration / pore structure / relative permeability coefficient / grey correlation analysis method
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