Study On Synthetically Anti-cracking Technique Of Semi-rigid Base In High-grad Highway

The semi-rigid base asphalt pavement has excellent mechanical characteristics andpavement performances, which has become the main pavement structure in expresshighways in China. However, there are sill exist many questions for semi-rigid base asphalt pavement, mainly presented as pavement cracking. The serious base cracks reducethe road capacity and lead to the destruction of asphalt pavement layers. But up to now,effective method has not been found to prevent cracks growing in semi-rigid base as phaltpavement based on present investigation.In order to reduce the shrinkage of semi-rigid materials and enhance its ability tocrack, this paper develops low-cost and micro-expansion anti-cracking agent, which ismade from chemical waste pozzolanic reaction. By mixing the semi-tigid materials withanti-cracking agent, the basic mechanical properties such as and shringkage properties hadbeen studied; the micro formation of ettringite in cement system had been observed by thescanning electronic microscope (SEM) and ANSYS analysis.The results show that semi-rigid base added anti-cracking agent has a goodmicro-expansion and intensity, and the shrinkage space of the semi-rigid materials as aresult of changes of temperature and humidity can be greatly reduced. The anti-crackingagent can reduce pavement cracks greatly and extend the road service life.