骨料种类与级配对路面混凝土耐磨性能的影响

提高路面混凝土耐磨性能对行车安全和道路服役寿命具有重要意义。本文通过优化普通砂石骨料架构提高道路混凝土的耐磨性能,研究了机制粗骨料级配、细骨料种类与用量、胶凝材料用量及水胶比对路面混凝土力学性能与耐磨性能的影响。结果表明,16~31.5 mm碎石由质量分数25%增加到70%时,混凝土磨损量降低了29%。与河砂混凝土相比,机制砂混凝土磨损量降低58.3%,同时适当增加砂率可提高耐磨性能。降低胶凝材料用量和水胶比可在保证混凝土强度的同时进一步提高耐磨性(磨损量仅为(0.320±0.070) kg/m²)。机制骨料表面粗糙,棱角较多,与水泥浆体机械咬合力增强,有利于骨料嵌锁架构的形成,路面混凝土耐磨性能改善机制的提出为优化设计高耐磨路面混凝土提供了理论依据与技术支撑。

Effects of Type and Gradation of Aggregate on Wear Resistance of Road Concrete

Improving the wear resistance of road concrete is beneficial to driving safety and road service life. In this study, the wear resistance of concrete was improved by optimizing particle packing of aggregate. The effects of coarse aggregate gradation, type of fine aggregate, sand ratio, amount of cementitious material, and water-to-cementitious material ratio on the mechanical properties and wear resistance of road concrete were investigated herein. The results show that the wear loss of concrete reduces by 29% when the mass fraction of coarse aggregate with diameter of 16~31.5 mm increases from 25% to 70%. The wear loss of concrete with manufactured sand reduces by 58.3% compared with that with river sand. Higher wear resistance of concrete is achieved by using higher sand ratio. Moreover, reducing the amount of cementitious material and water-to-cementitious material ratio rationally are effective ways to improve the strength and wear resistance of concrete (the abrasion loss is low as (0.320±0.070) kg/m²). The enhancement of bonding between manufactured aggregates and cement paste, which can be attributed to the rough surface and angular of manufactured aggregates, is beneficial to the formation of stable interlocking skeleton. The present investigation provides theoretical foundation and technical support for design and optimization of high wear resistance road concrete.