纳米颗粒对井壁混凝土耐久性能的影响

为了改善矿山井壁混凝土的耐久性能,利用2种纳米颗粒作为外掺材料制备混凝土试件,并开展强度、耐磨性和干缩性试验。结果表明,纳米材料在提高井壁混凝土抗压和抗弯强度的同时,也改善了耐磨性能和干缩性能;双掺NS和NC颗粒的含量为3%和2%的水工混凝土具有最优的耐冲磨性能,耐磨测试的磨损量仅为0.64 kg/m^2,比参照组磨损量降低了85%;与普通水泥砂浆相比,双掺2%NS和3%NC的水泥砂浆干缩率提高了128%,此配比为改性的最优组合;从改性前后的混凝土微观形貌发现纳米颗粒的填充效应和火山灰反应是混凝土耐磨性能提升的主要原因,黏结作用和表面反应是干缩性能提高的主要原因。

Influence of Nano-particles on Durability of Shaft Concrete

To improve the abrasion resistance and dry shrinkage resistance of concrete for shaft lining,nano-particles were used as admixtures in the modification of concrete.The results show that NS and carbon fiber not only improve the compressive strength and flexural strength of concrete,but also improve the wear resistance and dry shrinkage performance of the material.The concrete with double NS and NC content of 3%and 2%has the best impact wear resistance.The impact wear test wear is only 0.64 kg/m^2,which is 85%lower than that of the reference group.Compared with common cement,the dry yield of cement mortar mixed with2%silica powder and 3%carbon fiber is increased by 128%.It is found from the microstructure of concrete before and after modification that the main reasons for the improvement of the abrasion resistance of the filler material of NS powder particles are as follows:the adhesion of NC and the reaction are the main reasons for the improvement of the dry shrinkage performance.