黏土基铸造废旧砂特性及其对砂浆性能的影响

Characteristics of Clay-based Foundry Waste Sand and Its Influence on Properties of Cement Mortar

分析了黏土基铸造废旧砂的特性,研究了黏土基铸造废旧砂对砂浆性能的影响。结果表明:黏土基铸造废旧砂中含有微量重金属,但在相关环境标准许可范围内;与河砂相比,黏土基铸造废旧砂的颗粒形貌不规则、细颗粒较多;黏土基铸造废旧砂的表观密度与河砂接近,但堆积密度显著低于河砂,吸水率、亚甲蓝值和氯离子含量显著大于河砂;该黏土基铸造废旧砂的细度模数为1.76,属于Ⅲ区砂;当黏土基铸造废旧砂的替代率小于20%时,对砂浆的流动度和减水剂用量影响不大;当黏土基铸造废旧砂的替代率为40%时,砂浆的强度达到最高。

The characteristics of clay-based foundry waste sand were analyzed,and the influence of clay-based foundry waste sand on the properties of cement mortar was studied.The results show that the clay-based foundry waste sand contains trace heavy metals,but it is within the allowable range of relevant environmental standards.Compared with river sand,the clay-based foundry waste sand has irregular particle morphology and more fine particles.The apparent density of the clay-based foundry waste sand is close to that of river sand,but the bulk density is significantly lower than that of river sand,and the water absorption,methylene blue value and chloride ion content are significantly higher than those of river sand.The fineness modulus of the clay-based foundry waste sand is 1.76,which belongs to the zoneⅢsand.When the replacement rate of clay-based foundry waste sand is less than 20%,it has little effect on the fluidity and the water reducing agent amount of the cement mortar.When the replacement rate of the clay-based foundry waste sand is 40%,the strength of the cement mortar is the highest.