The Gradation Design Of Lime-fly Ash Stabilized Aggregates And Studying Of Pavement Performance

With the rapid development of highway transportation in our country lime-fly ash stabilized aggregates mixtures have been applied widely for its excellent pavement performance.The aggregates gradation of lime-fly ash stabilized aggregates which is recommended by Design Specification of Highway Asphalt Pavement is finer, so that the anti-brushing performance and the anti-crack performance of lime-fly ash stabilized aggregates are worse.In this paper, based on the practical use of the asphalt concrete pavement on Semi-rigid base, the performance of Lime-fly ash Concrete base is profoundly researched. So we know Semi-rigid mixture should be of logical combination rate to make a asphalt concrete pavement on Semi-rigid base obtain excellent performance.In order to improve the pavement performance of lime-fly ash stabilized aggregates and make coarse aggregates form skeleton, the paper confirm the rate of voids of the mixed aggregates by the method of vibrating test. On the basis of which, the grade of coarse aggregates is confirmed. The experimental results are validated through the theory calculation.Firstly, the ratio of lime to fly-ash is confirmed by the unconfined strength index. Secondly the grade of fine aggregates is calculated by the k method. Thirdly the ratio of fine aggregates to the lime-fly ash is confirmed by the test of unconfined strength.Fourthly, the suited ratio of coarse aggregates to ash-fly ash mortar is confirmed by the volume method. At last, the proportion of lime-fly ash stabilized aggregates mixture is confirmed.On the basis of single factor test, the orthogonal experimental study is presented on the suited composing of lime-fly ash mortar. The best experimental project is selected in the experiment. Simultaneously, the distinct effect of every factor is studied in the paper.In this text, based on the lime-fly ash stabilized aggregates mixture design, the pavement behavior and performance of designed mixture is studied and contrasted with the mixture which is recommended by the Design Specification of Highway Asphalt Pavement, including mechanical performance, stableness, anti-brushing performance, the anti-crack performance and fatigue performance.The laboratorial test confirms the time of pre-brushing. The value index of brushing of lime ash-flying stabilized aggregates is confirmed by the laboratorial test.