粉煤灰混凝土路面工作性能的纳米改性试验研究

Experimental study on nano-modified pavement performance of fly ash concrete

为了研究纳米材料对粉煤灰混凝土工作性能的改性效果,对不同纳米氧化硅掺量下的混凝土开展强度、表面耐磨性、抗冻融耐久性、干缩性及扫描电镜的测试,同时根据微观形态对改性机理进行了探究。试验结果发现纳米氧化硅掺入率为2%可使混凝土具有较高的强度、表面耐磨度、抗冻融耐久性和较低的干缩性等优良性能,建议该配合比为路面混凝土的设计配合比;混凝土抗折强度与表面磨损率呈负相关的线性关系;在微观层面上,纳米氧化硅颗粒的改性作用可以降低混凝土的孔隙率,形成屏障阻止裂纹扩展,从而达到改善水泥砂浆密实度结构的目的。

In order to study the modification effect of nanomaterials on the working performance of fly ash concrete,tests were carried out on the mechanical properties,freeze-thaw resistance durability,dry-shrinkage and wear resistance of concrete with different dosage of nano silica.Meanwhile,the modification mechanism was explored based on the observation results of microstructure.Through the performance evaluation of concrete with different mix ratio,it is found that the mix ratio of 2%nano silicon oxide makes the concrete have high strength,high frost resistance,low dry shrinkage,high wear resistance and other excellent properties,and it is suggested that the mix ratio should be the design mix ratio of pavement concrete.At the micro level,the modification of nano silica particles can reduce the porosity of concrete and form a barrier to prevent crack propagation,so as to achieve the purpose of improving the compactness structure of cement mortar.