Comparison between the effects of superfine steel slag and superfine phosphorus slag on the long-term performances and durability of concrete

Superfine particles have been used as mineral admixtures to enhance physical properties, mechanical properties, and durability of concrete in a lot of research. In this study, superfine steel slag (FSS) and superfine phosphorus slag (FPS) were ground to 643 and 657 m(2) kg(-1), respectively. The water-to-binder (W/B) ratios were set as 0.45 as well as 0.35, and the cement replacements adopted were 15 and 30%. The effects of FSS and FPS on long-term performance and durability of concrete were investigated. The results show that the increase amplitude of reaction degree of FPS is higher than that of FSS at late age (after 90 days). FPS can improve the pore structure of concrete which is beneficial to the resistance to carbonation and chloride ion penetration for concrete at late age while FSS cannot. FPS is also more advantageous to the development of compressive strength and splitting tensile strength of concrete when compared to FSS at late age. FPS is much more beneficial to the resistance to sulfate attack of concrete while FSS is more disadvantageous to the resistance to sulfate attack of concrete as the replacement ratio increases.