黄金尾矿掺量对冻融循环和硫酸盐侵蚀作用下混凝土抗劣化性能的影响

Effect of Gold Tailings Content on the Deterioration Resistance of Concrete under the Combined Effect of Freeze-thaw Cycle and Sulfate Attack

为探究黄金尾矿掺量对混凝土力学性能及在冻融循环和硫酸盐侵蚀联合作用下的抗劣化性,利用电液伺服压力机对细黄金尾矿机制砂掺量为0%、5%、10%、15%、20%、25%、30%的试件静态力学性能进行了测试分析,并研究了素混凝土及细黄金尾矿机制砂混凝土在冻融循环及硫酸盐侵蚀联合作用下的抗压强度劣化规律。试验结果表明:①黄金尾矿机制砂的掺入能够极大改善混凝土材料的延展性,对提升建筑物的安全性具有重要意义;②相较于未掺尾矿机制砂试件,掺量为5%、10%、15%、20%、25%、30%时试件抗压强度增幅为8.04%、10.87%、21.04%、17.73%、3.31%、-9.22%,抗拉强度增幅为15.04%、20.70%、31.25%、36.72%、29.10%、14.06%,适量黄金尾矿的掺入能够有效提高混凝土材料的力学性能,且最佳掺为20%;③冻融循环及硫酸盐侵蚀联合作用对2种混凝土试件均存在劣化作用,且随着冻融循环次数增加及硫酸盐浓度增大试件劣化程度不断增加;④黄金尾矿机制砂混凝土试件在浓度为0%的硫酸盐溶液下冻融循环50、100、150、200、250次时,试件抗压强度降幅仅为素混凝土的43%、44%、47%、45%、47%,尾矿在试件内部与骨料间良好的黏结作用提高了试件抗外荷载能力以及抗盐侵蚀、抗冻融能力。

In order to investigate the mechanical properties of concrete and the resistance to deterioration under the combined effect of freeze-thaw cycle and sulfate attack,the static mechanical properties of fine gold tailing mechanism sand with 0%,5%,10%,15%,20%,25%,30% specimens were measured by electro-hydraulic servo press,and the deterioration of compressive strength of plain concrete and fine gold tailing mechanism sand concrete under the combined effect of freeze-thaw cycle and sulfate attack were studied.The results show that:①The incorporation of gold tailing mechanism sand can greatly improve the ductility of concrete materials,which is important to enhance the safety of buildings.②Compared with the specimens without tailing,the increase of compressive strength was 8.04%,10.87%,21.04%,17.73%,3.31%,-9.22% and tensile strength was 15.04%,20.70%,31.25%,36.72%,29.10%,14.06% for 5%,10%,15%,20%,25% and 30% of the specimens,the appropriate amount of gold tailing can effectively improve the mechanical properties of concrete materials,and the best blend of 20%.③The combined effect of freeze-thaw cycles and sulfate erosion on both concrete specimens have deterioration effect,and with the increase in the number of freeze-thaw cycles and sulfate concentration increases the degree of deterioration of the specimens.④The compressive strength of the concrete specimens with gold tailing in 0% sulfate solution was only 43%、44%、47%、45%、47% of plain concrete when the specimens were subjected to freeze-thaw cycles of 50,100,150,200 and 250 times,and the good adhesion between the tailing and the aggregates inside the specimens improved the resistance of the speci-mens to external loading as well as the resistance to salt erosion and resistance to freeze-thaw resistance.