Study On Additives And Methods Of Recycling Old Flexible Pavements

Since the 1990s, lots of high-grade pavements, especially flexible pavements, have been constructed in our country, which results in lake of bitumen and aggregate. Meanwhile, many flexible pavements have become old and need repair. Old asphalt mixtures need large field for piling and are disposed hardly. If disposed incorrectly, they will pollute soil and water source. So, in order to save the sources and protect environment, it is important to develop recycling old flexible pavements in our country now.This thesis involves two parts of research contents. One is research of additives; another is research of recycling approaches and equipments.Research institute of road of Dalian University of Technology attempts to use one sort of industry material as additive (named TY-X additives).compared with another two additives A and B respectively provided by two research institutes of south and north china, by test of regenerating old asphalt, TY-X additive is the best one among them. Tests of Marshall stability, immersion Marshall and track about TY-X additive regenerating old asphalt mixture under the 30, 40 and 50 ratios of old asphalt mixture indicate technical parameters of its reclaimed asphalt mixture all satisfy technical standard of highway hot-mixed asphalt mixture. Test of immersion Marshal indicates TY-X additive has the good performance of resisting damage of water. Splitting test of reclaimed asphalt mixture at the low temperature is also done.By compare of approaches and equipments of in-factory and in-place hot recycling, a new approach and equipment of in-place hot recycling is put forward by us.