铁尾矿球替代粗骨料的新型混凝土力学性能试验研究

Experimental study on mechanical properties of new concrete with the coarse aggregate replaced by iron tailing powder bonded balls

通过试验研究了使用铁尾矿粉制作成的尾矿球的物理性能,并使用尾矿球作为粗骨料配制不同强度配合比的混凝土。通过系统试验研究了骨料强度、水胶比等因素对混凝土的强度、弹性模量等物理力学性能的影响。研究表明:尾矿球较大的空隙率和较小的比表面积使得在进行配合比设计时,砂率要比同水胶比下的普通混凝土增加5%~7%左右;由于尾矿球本身密度大但强度较低,因此尾矿球混凝土的强度整体较低但弹性模量较大。使用鲍罗米公式拟合后得到的回归系数为αa=0.23、αb=-1.16与现有规范中给出的普通卵石骨料的参考回归系数有较大差异。尾矿球混凝土的破坏形态也随着水胶比降低从以骨料剥落破坏为主过渡为以骨料破坏为主。

Through experiments,the physical properties of tailing balls made of iron tailings powder were studied,and the tailing balls was used as coarse aggregate to configure concrete with different strength mixture ratio.The effects of aggregate strength,water-binder ratio,etc on the strength and elastic modulus of tailing balls concrete were studied by systematic tests.The results show that,the larger air voids and the smaller specific surface area of tailing balls make the sand ratio increase by 5% to 7% than that of ordinary concrete under the same water-binder ratio.Because of the high density and low strength of tailing balls,the overall strength of tailing balls concrete is low but its elastic modulus is high.The regression coefficients αa=0.23,αb=-1.16 obtained by using the bowromi formula are quite different from the regression coefficients of common pebble aggregates given in the existing standard.With the decrease of water-binder ratio,the failure modes of tailing balls concrete changes from mostly aggregate peeling to mainly split aggregate.