金尾矿复合砂对不同强度等级混凝土性能的影响

Influence of Gold Tailing Composite Sand on Properties of Different Strength Grade Concrete

将金尾矿复合砂作为细集料替代天然砂,研究了金尾矿复合砂替代率对C30~C50混凝土和易性、抗压强度及耐久性的影响,并对力学性能较优组进行了微观结构分析。结果表明:当金尾矿复合砂替代率低于50%(质量分数)时,混合砂具有较优级配;当金尾矿复合砂替代率由0%增加至50%时,需通过调整外加剂掺量来保证金尾矿复合砂混凝土良好的工作性;当金尾矿复合砂替代率为20%~30%时,C30~C50混凝土不同龄期抗压强度、抗碳化性能和抗冻性能较未掺金尾矿复合砂基准组均有较大提升,微观水化产物相互交织增强了结构密实性。

The gold tailing composite sand was used as fine aggregate to replace natural sand,the effect of gold tailing composite sand replacement rate on workability,compressive strength and durability of C30~C50 concrete were studied,and the microstructure of group with better mechanical properties was analyzed.The results show that when the replacement rate of gold tailing composite sand is lower than 50%(mass fraction),the composite sand has better gradation.When the replacement rate of gold tailing composite sand increases from 0%to 50%(mass fraction),it is necessary to adjust admixture amount to ensure the good workability of gold tailing composite sand concrete.When the replacement rate of gold tailing composite sand is 20%~30%(mass fraction),the compressive strength,carbonization resistance and freezing resistance of C30~C50 concrete at different ages are significantly improved compared with the reference group without gold tailing composite sand,and the interweaving microstructure hydration products enhances the structural compactness.