Warm Mix Asphalt Optimal Design Based On Marshall Test

At the moment, global energy shortages and deteriorating trend of environmental pollution,domestic highway construction face new challenges. Bituminous pavement as the main type ofpavement, besides satisfies the technical requirements, it should develop in the direction ofgreen、energy conservation and environmental protection. Technology of warm mix asphaltoriginated in Europe, it can dramatically reduce asphalt mixing temperature. In addition, thetechnical index of warm mix asphalt is as good as hot mix asphalt, WMA is widely used inabroad. On account of inexperience, technology of warm mix asphalt is still at the research ofstage, WMA is not applied widely in domestic. Reasons for this situation are complex, the mainexistence question are imperfections of WMA design method、question WMA pavementperformance and economic benefits are not obvious, etc.For the sake of promote WMA application, content of the thesis is based on relativeresearch results, major research content is optimal design method for WMA. Influence of thewarm agents on the basis asphalt as a reference, analyze domestic organic additive warm agentsimpact on the performance of asphalt mixture. Learn from design method for HMA, tryapplying multilevel dense built-in gradation in WMA, attempt to optimal WMA performance ingradation. In the light of design principle of Superpave, apply its asphalt content formula inmarshall design method, and experiments are done to prove feasibility of this method. Adoptnew asphalt immersion test method to measure asphalt mixture theoretical maximum densityand aggregate effective density, sum up measure asphalt mixture and aggregate density skills.In terms of equal volume parameter design theory, research warm asphalt mixing temperaturereduce degree, sum up specific deterministic approach for warm asphalt mixing temperature. Interms of Marshall test、wheel tracking test、low temperature splitting test verify asphalt mixturepavement performance, advance specific deterministic approach for warm agents content.Adopting discrete element software establish the model of skeleton-density gradation. Thevirtual tests on the mixture structure stability were done. Use existing research results asreference, sum up WMA target gradation optimal design method based on Marshall test,advance points for attention between WMA design and HMA design.The research results show that compared with HMA, WMA design and performance hasits own characteristics. KSH-D warm agent can dramatically reduce asphalt mixing temperatureand the technical index of warm mix asphalt is as good as hot mix asphalt, it play an importantrole in energy conservation and environmental protection. Aggregate gradation have an effecton WMA pavement performance, it is reasonable to design specialized gradation for specificaggregate. Both warm agent and mixing temperature have an great effect on WMA volumefeature and pavement performance. WMA design based on Marshall test is different form HMA,it is reasonable to adopt optimal design method on warm mix asphalt.