Abstract: In order to analyze the crack resistance performance of cement-soil stabilized RAP mixture, specimens with different proportions were molded with the optimum moisture content and maximum dry density to undergo shrinkage test and fracture toughness test. The test results show that, with the increase of lime soil and cement content, the dry shrinkage coefficient and temperature shrinkage coefficient of the mixture show an overall growth trend. When the mixture is in the temperature range of 5~-5 ℃, the temperature shrinkage coefficient has a peak value, and the peak value increases with the increase of cement dosage. The fracture toughness test results of the mixture show that the fracture toughness of cement-soil stabilized RAP mixture increases with the increase of cement dosage or the decrease of lime soil dosage, indicating that the anti-crack propagation ability of the mixture also increases. And the fitting results show that the flexibility and the shrinkage coefficient have a high correlation, which means that the flexibility can accurately reflect the shrinkage resistance of the mixture. Based on this, the comprehensive consideration of fracture toughness and flexibility is proposed as the evaluation index of crack resistance of cold recycled mixture.

Key words: road engineering; crack resistance performance; pre-slit three-point beam bending; semi-rigid base course; flexibility; RAP

摘要： 为分析水泥土稳定RAP混合料的抗裂性能，在最佳含水率和最大干密度下成型不同配比的试件，并对其进行收缩试验和断裂韧度试验。试验结果表明：随着灰土掺量和水泥剂量增加，混合料干缩系数和温缩系数整体上呈现增长趋势，当混合料处于5~-5 ℃的温度区间时，温缩系数出现峰值，且峰值大小随水泥剂量的增加而增大。混合料断裂韧度试验结果表明：水泥土稳定RAP混合料的断裂韧度随水泥剂量增加或灰土掺量减少而增大，表明混合料抗裂纹扩展能力也随着增强。拟合结果表明：柔度和收缩系数之间具有较高的相关性，说明柔度能准确地反映混合料的抗收缩性能。基于此，可以将断裂韧度和柔度作为冷再生混合料抗裂性能的评价指标。

关键词: 道路工程；抗裂性能；预割缝三点梁弯曲；半刚性基层；柔度；再生沥青混合料