Study On Cold Patch Epoxy Emulsified Asphalt Mixtures

In the recent years, the transportation industry has witnessed the rapid development, however at the same time, many constructed roads suffer serious diseases such as cracking, rutting, loose peel and pit before design life ends, as a result, maintenance and repair of the existing road should be paid more attention. Using emulsified asphalt as a binder in road repair technic has great advantages such as mixed at room temperature, easy construction, energy conservation, extensive construction season etc. But on the other hand, the poor adhesion, slow strength molding, early strength and molding strength lower than hot asphalt mix limit the application of emulsified asphalt mixture in large-scale. In order to compensate for the shortcomings of emulsified asphalt, waterborne epoxy resin which has strong bonding, fast forming speed and high forming strength was added to emulsion asphalt, as a result, a fast repair, low-power patching material of the road was obtained.Two waterborne epoxy resins and two curing agents were selected, the theoretical optimal dosages of curing agents were calculated by measuring the epoxy value and solid content of the waterborne epoxy resins; The optimal experimental contents of the curing agents were obtained by measuring the compressive strength of the waterborne epoxy mortar using different curing agent contents at different ages; measuring the strength growing rules varies with temperature of the waterborne epoxy mortar; Under condition of optimal curing agent contents, the developing rule of the waterborne epoxy mortar strength at different temperatures was obtained as a way to assess the effect of temperature to solidifying speed. The difference between the two waterborne epoxy resins was obtained by the flexural strength and stress-strain curves which was measured by flexural test of the waterborne epoxy mortar, that is one of them is a flexible epoxy whereas the other one is a rigid epoxy.Based on the breaking mechanism of emulsified asphalt water-based epoxy resin curing mechanism, and combined with Moore-Coulomb theory of hot mix asphalt mixture, the strength forming mechanism and the characteristics of intensity formation of the epoxy emulsified asphalt has been analyzedThe mixture of the epoxy emulsified asphalt mixture was designed based on the cationic emulsified asphalt mixture ratio design method which was recommended by Ministry of Transportation Cation Topic Collaboration; The evaluation method of initial strength and molding strength of epoxy emulsified asphalt mixture was proposed for road pothole patching by the experimental study of compaction molding method and curing conditions of the mixture.The high temperature performance, low temperature performance and water stability of mixture were verified by the results of rutting test, low temperature bending creep test, residual stability test, freeze-thaw splitting test, adhesion test of the mixture.The study shows that using epoxy emulsified asphalt mixture as a road repair materials has great advantages in excellent pavement performance, energy conservation, and improving road service levels which could lead to greater economic and more social benefits.