碱激发复合废渣混凝土在冻融磨耗联合作用下的性能研究

摘要

利用NaOH和Na2SiO3,复合化学激发剂,矿渣、粉煤灰、石粉及其复合渣体,制各了高性能碱激发复合废渣混凝土(ACWC),并通过与硅酸盐混凝土(PC)进行工作性、强度、先冻融后磨耗、先磨耗后冻融和冻磨联合作用对比试验,研究了ACWC的物理力学性能、冻磨联合作用下的耐久性.结果表明,ACWC的工作性较PC大大改善,28 d抗折、抗压强度达8.86、95.6MPa,7 d抗折、抗压强度达7.67、84.7 MPa,较PC具有稳定的强度增长性能和较快的增长速度.ACWC和PC在冻磨频繁交替作用下的质量损失均比先冻后磨及先磨后冻大很多,但ACWC的质量损失均较PC小,在冻磨联合交替作用下,矿渣、粉煤灰、石粉三元复合渣体ACWC的质量损失率较PC降低了55%,大大提高了混凝土在冻磨联合作用下的耐久性.%High performance alkali-activated compound waste concrete(ACW) was prepared by adopting Na2SiO3,NaOH complex activator,slag,fly ash,limestone powder and compound waste residue. Physical,mechanical performance and durability on freeze-thaw and abrasion operation together were studied by workability,strength,abrasion after freeze-thaw,freezc-thaw after abrasion and freeze-thaw and abrasion operation together tests contrasted with Portland concrete(PC). The results revealed that workability of ACWC is superior to PC,28 d flexural strength and compressive strength of ACWC are 8.86 MPa and 95.6 MPa,7 d strength are 7.67 MPa and 84.7 MPa respectively,strength of ACWC increases steadily and quickly contrasted with PC. Mass loss of ACWC and PC on freeze-thaw and abrasion operation together are bigger than what on abrasion after freeze-thaw and freezethaw after abrasion, but mass loss of ACWC is smaller than PC,especially alkali-activated slag,fly ash and limestone powder compound waste residue concrete reduces by 55％ of PC on freeze-thaw and abrssion operation together,which greatly improve the durability of concrete on freeze-thaw and abrasion operation together.