Study And Applied On The Early Strength Cement-emulsified Asphalt Concrete

Cement concrete and asphalt mixture, when used as road building and maintainingmaterials, have the problems of complicated construction process, environmental temperature,humidity sensitivity and maintaining difficulties in later stage. For these problems, based onthe correlated domestic and overseas researching results, this paper developed a new kind ofsemi-flexible pavement materials——The early strength cement emulsified asphalt concrete.The material has properties of high early strength, high temperature stability, convenientconstruction and fine durability, which combines the advantages of cement concrete andasphalt mixture.This paper studied the co-adaptation of cementing material, emulsified asphalt, aggregateand admixture, and established the raw materials, quality control index of the early strengthcement emulsified asphalt concrete. By researching the rule of influence of key parameterssuch as composition materials, water-cement ratio and sand ratio on the early strength cementemulsified asphalt concrete’s working and mechanical properties, the paper determined thekey preparation parameters and put forward the mix design method of the early strengthcement emulsified asphalt concrete.The anti-rutting performance, water stability, erosion resistance to chemical medium andfrost resistance of the resistance of early-strength cement emulsified asphalt concrete werestudied systematically. Meanwhile, the influencing factors and affecting law of variousperformances were analysed comprehensively. The results showed that the pavementperformance and durability of early strength cement emulsified asphalt concrete are fine,matching the requirements of the relevant technical specifications and design specifications.The results provide an important reference for the preparation of the early strength cementemulsified asphalt concrete.The studies of mechanism of strength showed that the strength of the early strengthcement emulsified asphalt concrete was formed by the combined effect of cementingmaterials and emulsified asphalt. The cementing material played a major role on the earlystrength, high temperature performance and water stability in the formation of strength, andaccelerated the demulsification of emulsified asphalt. While emulsified asphalt could supply water for cementing materials, hydration after breaking of emulsion, and could formed anetwork-like structure in the early strength cement emulsified asphalt concrete, thus enhancedthe flexibility and toughness of this material.The microscopic structure of the early strength cement emulsified asphalt concrete wasstudied through the SEM modern analysis method. The results showed that there were manyinternal pores in cement emulsified asphalt slurry in early hydrating, and the residual asphalt,aggregate and unhydrated cement involvemented and formed a space network, providingearly strength for the slurry. With the increase of hydration time, the porosity reduced, and thenew hydration products reinforced the skeleton structure. Asphalt content will have an impacton the microstructure of the slurry, thereby affecting the mechanical properties of the slurry.The studies of the mechanism of interfacial bond strength showed that the interfaceenhancement processing could improve the Interface bonding strength of the early strengthcement emulsified asphalt concrete with cement concrete and asphalt mixture.Through applying the research results to the test section, this paper put forward theengineering application technology of the early strength cement emulsified asphalt concrete.