National Key Research and Development Program of China (No. 2021YFB2601000), National Natural Science Foundation of China (NSFC) (No. 52078048), Fundamental Research Funds for the Central Universities, CHD (300102212708)
The effect of aggregate shape on the embedding structure and spalling resistance of chip seals was investigated using self-developed algorithms and a wheeled accelerated loading wear tester. The results show that the negative effect of elongated aggregates on the percentage of aggregate embedding is insignificant. In order to ensure good spalling resistance, the content of elongated aggregate should not be higher than 16%. The flat aggregate is mostly distributed tiled or vertically, resulting in displacement or spalling of adjacent aggregates, which is detrimental to the aggregate embedment and retention of chip seals. It is recommended that the flat aggregate content be kept below 10%. In addition, the mass loss of the chip seal after abrasion increases by approximately 2% when flat aggregate and elongated aggregate are both present. The percentage of aggregate embedding area PEA is an ideal indicator for evaluating the performance of chip seals, as it combines good stability and sensitivity.