全尾矿废石骨料高强混凝土的试验研究

从资源再生、生态环境保护和循环经济的角度出发,以重新级配后的密云地区铁矿废石为粗骨料、密云地区铁尾矿为细骨料,将铁尾矿与矿渣、水泥熟料、脱硫石膏通过梯级混磨得到混合料,与单独磨细的钢渣粉混合为胶凝材料,加入减水剂和水后制备成高强混凝土材料,并采用X射线衍射(XRD)、扫描电子显微镜(SEM)、能谱分析(EDS)等手段进行微观结构与物相组成的变化研究,进而分析反应机理。所制备的混凝土的固废总比例达到91%,使用废石代替天然石子,铁尾矿代替天然砂子,其天然砂石替代率达到100%,制得的混凝土试块28 d抗压强度达到75.92 MPa。

Experimental Study of High-strength Concrete with Waste Rocks and Iron Tailings as Aggregates

From viewpoints of resources regeneration，environmental protection and circular economy，the re-graded waste rocks in Miyun area were prepared as coarse aggregate，and iron tailings were prepared as fine aggregate.Then，iron tailings，blast furnace slag，cement clinker and FGD gypsum were mixed and ground to produce the mixture.Steel slag that was ground alone are together with the mixture to prepare cementitious materials.The high-strength concrete materials were produced with the cementitious materials and aggregates，by adding water- reducing agent and water.The changes of microstructure and phase composition of the high- strength concrete were studied by XRD，SEM，EDS，et al.Based on this，its reaction mechanism is analyzed.The produced concrete materials obtained the compressive strength as high as 75.92 MPa at 28 d and the content of wastes in products reached 91%.The replacement ratio of natural sands and rocks was 100% while natural sands were replaced by Miyun iron tailings and natural rocks were replaced by Miyun waste rocks.