Effects of Fineness and Content of Phosphorus Slag on Cement Hydration, Permeability, Pore Structure and Fractal Dimension of Concrete

Abstract

The utilization of phosphorus slag (PHS) to replace the fly ash in the construction of hydraulic projects has attracted a growing attention in China. In this study, the influence of PHS fineness and content on cement hydration, mechanical strength, permeability as well as the pore structure and fractal dimension (Ds) of concrete have been discussed. The results indicate that the PHS addition retards the cement hydration and hence decreases the hydration heat within 3 days. The incorporation of PHS with a Blaine specific surface area of 505 m 2 /kg (PHS) could participate in the early pozzolanic reaction and consequently offsets the retarding effect to some extent. The incorporation of 20-40 w% PHS declines the early strength of concrete, but this reduction effect on strength can be eliminated to some degrees by mechanically grinding the PHS. The compressive strengths of concrete added with PHS with a high fineness of 505 m 2 /kg

Comparative Study on the Mechanical Strength of SAP Internally Cured Concrete

“…After the SAP particles lose water, a large number of honeycomb holes are left in the hardened concrete stones, thus reducing the effective cross-sectional area. The pore structure of SAP concrete has been modified by SAP particles, similar to the effects caused by fly ash, silica fume and other additive admixtures (Wang et al, 2020a;Wang et al, 2020b;Wang et al, 2020c). At the same time, it easily causes stress concentration when the concrete specimen is compressed.…”

Effect of Tuff Powder Mineral Admixture on the Macro-Performance and Micropore Structure of Cement-Based Materials

“…The above MIP results could be used to characterize the porosity distribution and evolution of tuff powder-cement paste, but fail to characterize the complexity of the internal pore structure. For this purpose, the relevant literature applies the fractal theory to analyze the pore structure of cement-based materials (Wang et al, 2020a;Wang et al, 2020b). The fractal dimension of the pore surface (Ds) is introduced to quantitatively characterize the surface characteristics of the irregular pore structure of tuff powder-cement paste.…”

“…The fractal dimension of the pore surface (Ds) is introduced to quantitatively characterize the surface characteristics of the irregular pore structure of tuff powder-cement paste. Studies have (Wang et al, 2020a;Wang et al, 2020b;Wang et al, 2020c;Rahman, 1997) shown that the surface fractal dimension value is primarily related to the pore distribution characteristics. The Ds is within the range of 2-3.…”

Water-to-Cement Ratio of Magnesium Oxychloride Cement Foam Concrete with Caustic Dolomite Powder

“…The strength of MOC can be reduced with the introduction of waste [14]. The MgCl 2 used in the laboratory or small amounts of MgCl 2 used to study MOC material are obtained as high-purity raw materials [23,24], and some errors may be involved in practical industrial applications when an impure raw material is used [25]. Due to the number of raw materials, their relationships with concrete performance have a great impact [26,27].…”