Preparation of Ultra-High Performance Concrete Using Phosphorous Slag Powder

Abstract

Reactive powder concrete (RPC) is an ultra-high performance concrete (UHPC). Cement and silica fume content of RPC are generally rather high compared to the conventional concrete. The aim of this paper is to decrease the cement content of RPC by using phosphorous slag powder. Firstly the effect of grinding time on the activity index of phosphorous slag was investigated. And then, the mix proportion design of this UHPC containing phosphorous slag powder and silica fume was done through orthogonal design. The results indicate that the utilization of phosphorous slag powder in RPC is feasible when the dosage of phosphorous slag powder is about 35% (by weight of the binder) and the water-binder ratio is less than 0.18. By substituting phosphorous slag powder for a part of cement and keeping the water-binder ratio at about 0.14, UHPC specimens whose content of mineral admixtures, including phosphorous slag powder and silica fume, was about 40%~50% (by weight of the binder) were obtained after they had been cured in 80 °C water for 72 hours. The compressive and flexural strength of those specimens was more than 150 MPa and 20 MPa respectively.

The Role of Supplementary Cementitious Materials (SCMs) in Ultra High Performance Concrete (UHPC): A Review

“…The fineness of LTS is between those of cement and SF, which can improve the packing density of UHPC and the pozzolanic reaction of LTS also contributes to the late age compressive strength development. Peng et al used PS that has a similar glass structure to GGBS [ 48 ]. When PS content increased from 30% to 35%, the compressive strength increased by 3.7% because the addition of PS increased both the degree and speed of the pozzolanic reaction, which results in more hydration products in the paste and low porosity.…”

Optimization for Mix Proportion of Reactive Powder Concrete Containing Phosphorous Slag by Using Packing Model

“…For RPC, its cement consumption is very high, generally 400 -900 kg/m 3 and the content of silica fume is often over 25% of the cement mass. Moreover, previous studies (Peng et al 2013;Sun et al 2013) have demonstrated that the amount of water used in RPC containing phosphorus slag (PS) had better be less than 200 kg/m 3 and the water-binder ratio could be less than 0.20, and phosphorus slag should be less than 40% of the mass of binder. Therefore, the technical restrictive conditions are:…”

“…Replacing cement with mineral admixtures, including granulated blast furnace slag, fly ash, steel slag, rice husk ash, and decreasing SF content seemed to be a possible solution to these problems (Liu et al 2003;Nguyen et al 2011;Peng et al 2010;Xiao et al 2013;Yazıcı et al 2008Yazıcı et al , 2009Yiğiter et al 2012). Previous studies suggested that incorporation of phosphorous slag powder (PS) in RPC was feasible (Peng et al 2013(Peng et al , 2015.…”

Modeling the Effect of Alternative Cementitious Binders in Ultra-High-Performance Concrete

“…The effect of blast furnace slag (BFS) incorporation in UHPC can vary depending on the curing age. The incorporation of BFS in UHPC is generally known to decrease the compressive strength at early age (1–3 days) by 18–39% [ 18 ], while the strength can be higher in the BFS-containing UHPC in comparison with the plain one after 28 days [ 19 , 20 ]. The effect of BFS on the properties of UHPC can also vary depending on its replacement ratios.…”