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Full thickness cold recycling subgrade materials were prepared by cement-emulsified asphalt solidified RAP and stabilized soil.The effect of adding amount of emulsified asphalts change on unconfined compressive strength, indirect tensile strength and water stability of cold recycled mixtures with different ratios was studied,and the mechanism of action of cement and emulsified asphalt in the mixtures was analysised via microscopic test. The results show that a proper addition of emulsified asphalt can improve the performance of cold recycled mixtures and the best emulsified asphalt mixing content is 3%. Microscopic test indicate that the cement hydration products space network structure interfinger with the emulsified asphalt network structure, so the cold recycled mixture tightly coupled to a semi-rigid whole, and the mixtures strength can form and develop.

Compressive strength, setting time, hydration heat and hydration product were investigated to evaluate the effects of Zn2+ ion concentrations and the anion of zinc salts on the hydration characteristics of Portland cement paste. The results show that the hydration characteristics of zinc-doped cement pastes depend on Zn2+ ion concentrations and the anion of salts. With the incorporation of ZnCl2, the hydration heat, exothermic rate and the early-age strength of cement pastes were reduced, the arrival time of the highest temperature was delayed, and little negative influences on the compressive strength at 28 days were observed. The total hydration did not decrease incorporating ZnSO4; the hydration exothermic process was delayed. There were little negative influences on the compressive strength of the samples at 3 days and 28 days. Moreover, for the samples with the same Zn concentration, the retardation effect of ZnCl2 samples was stronger than that of ZnSO4 samples.

According to the system of asphalt pavement cold in-place recycling(APCIR), added proper Na2SO4 into different designed reclaimed asphalt pavement(RAP), the mechanical property effect of Na2SO4 on cement-reclaimed asphalt pavement mixture was studied. It showed that early strength of RAP rose with adding more Na2SO4. After adding Na2SO4, the strength of RAP in 5d would increase 12% than that RAP without adding Na2SO4, this technology will play the important role in asphalt pavement repairment.