无砂混凝土基层配合比的优化与抗冲刷性能

Mix Proportion Optimization and Anti-scouring Performance of No-Fines Concrete Base

摘要:

为了提升无砂混凝土基层材料的抗冲刷特性，以7 d无侧限抗压强度、渗透系数和抗压回弹模量为评价指标，采用响应面法确定了无砂混凝土的最优配合比，开展了冲刷试验，分析了冲刷时间、冲刷频率和冲击强度对无砂混凝土抗冲刷性能的影响，揭示了无砂混凝土经过不同冲刷条件后强度和模量的衰减规律。结果表明：无砂混凝土的最优配合比为级配Ⅰ、水灰比0.35和目标孔隙率18%；相较于水泥稳定碎石而言，无砂混凝土具有更好的力学特性和抗冲刷性能。

Abstract:

To improve the anti-scouring performance of no-fines concrete base material， the optimal mix proportion of no-fines concrete was determined by the response surface method， using 7-day unconfined compressive strength， permeability coefficient， and compressive resilient modulus as the evaluation indices. The scouring test of no-fines concrete was carried out to analyze the effects of scouring time， scouring frequency， and impact strength on anti-scouring performance and to reveal the attenuation law of strength and modulus of no-fines concrete after different scouring conditions. The results show that the optimal mix ratio of no-fines concrete is gradation Ⅰ， with a water-cement ratio of 0.35 and a target porosity of 18%. Compared to cement-stabilized gravel， no-fines concrete exhibits better mechanical properties and anti-scouring performance.