| As a kind of by-products by yellow phosphorus industry through electric furnace process, large amounts of phosphorous slag are produced every year in our country. Phosphorous slag is piled as waste residue in most yellow phosphorus company in our country, which is harmful to the sustainable development of society and environment. Phosphorous slag can be used as mineral admixture because of its hydraulic potential, which is a good way to reusing it largely. At the same time, there are high environment, society and economic benefit if the phosphorous slag is reused recycling.Phosphorus slag has certain influence on the performance as a kind of mineral admixtures. At present, there are very few researches on the influence of phosphorous slag on hydration of cement and durability of concrete, especially on the properties of chloride ion penetration. In this paper, the effect of phosphorous slag produced in Sichuan ChuanFu New Building Materials Co., Ltd on hydration of cement, mechanics properties, properties of chloride ion penetration and pore structure of concrete are studied. The main results show that:①The hydration of cement was delayed as mixing with phosphorous slag. The hydration heat and the non-evaporable water are decreased; meanwhile, the exothermic rate of hydration is been slower when mixing with phosphorous slag. After mixing with phosphorus slag, the hydration products are similar with the hydration products of cement, but the Ca (OH)2 decreased.②Phosphorus slag is a good kind of mineral admixture of concrete. As a mineral admixture to increase the 56d compressive strength of concrete, the effect of phosphorus slag is lower than blast furnace slag, better than fly ash.③The permeability resistance of concrete against chloride ion penetration increases significantly by adding phosphorus slag. When the water to binder ratio of the mixes are 0.55, 0.45, 0.37 and the content of phosphorus slag within 40%, the permeability resistance of concrete against chloride ion penetration increase as the content of phosphorus slag increase. The resistance to chloride ion penetration of concrete increases with the fineness of phosphorus slag increases after 56d ages when the surface area of phosphorus slag is in the range of 274453m2/kg.④The resistance to chloride ion penetration of concrete increases by mixing phosphorus slag with fly ash or blast furnace slag according to 1:1. ⑤The pore structure of concrete has been improved by mixing phosphorus slag.The average pore diameter decreases and the percentage of the pores with diameter less than 20nm in concrete increases. |
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