Pore structure characteristics and performance of construction waste composite powder-modified concrete

A Study on Chloride Corrosion Resistance of Reactive Powder Concrete (RPC) with Copper Slag Replacing Quartz Sand under Freeze–Thaw Conditions

“…Pores with sizes of 0.01~2 µm are used to calculate the fractal dimension D l of the pore throat, and the pores with sizes of 2~1000 µm are used to calculate the fractal dimension D S of the pore surface [ 26 ].…”

“…Zhu et al [ 25 ] found that the pore size distribution of recycled aggregate concrete under chloride ion corrosion has similar fractal characteristics, and the fractal dimension increases first and then decreases with the increase in pore size. Guo et al [ 26 ] studied the effect of construction waste composite powder materials as supplementary cementitious materials on the performance of concrete and found that the pore size fractal dimension can characterize the pore structure of concrete, which has a significant correlation with compressive strength and the chloride ion diffusion coefficient. Jin et al [ 27 ] thought that the fractal dimension could quantitatively characterize pore structure and established a freeze–thaw damage model with fractal dimension.…”

Study of Concrete Strength and Pore Structure Model Based on Grey Relation Entropy

“…Of note, Equation (8) proposed in this paper firstly performs GRE analysis to find the sensitive pore size, which leads to certain limitations in the use of Equation (8). The use of Equation (8) requires that the pore structure data must meet conditions that the pore radius range is consistent and the concrete strength grade and age should also be consistent.…”

“…It should be noted that Equations ( 9)-( 12), which consider only the impact of porosity on the concrete's strength, the correlation coefficient reaches 0.535 on average; Equation (13), considering the factors of average pore radius and porosity, has a correlation coefficient of 0.578; Equation (6), taking into account the average pore radius, porosity, and cement content, has a correlation coefficient of 0.780; Equation (8) has the largest fitting accuracy, reaching 0.850, and the concrete's strength is related not only to porosity, but also to average pore radius, cement content and sensitive pore radius. Considering the influence of the sensitive pore radius on the strength of concrete, it is more reasonable to predict the strength of concrete with Equation (8) proposed in this paper.…”

“…Back in 1960, Powers [ 3 ] presented the theory of gel-to-air ratio, which linked the strength of concrete with the volume of capillary pores and concluded that the number of pores in concrete and the pore size range are related to the initial water–cement ratio and the hydration degree of the cement. Based on that strength theory, Balshin [ 4 ], Schiller [ 5 ], Hansen [ 6 ], Ryshkewitch [ 7 ], Guo and Wu [ 8 ], as well as Jons and Osbaeck [ 9 ], proposed different formulas that related the concrete’s strength to porosity. However, these formulas consider only the influence of porosity on the concrete’s strength, neglecting all other influencing factors.…”