Prediction of durability was carried out according to pavements renewed using technology proposed by Road and Bridge Research Institute (IBDiM). Technology of reconstruction consisted of old asphalt pavement milling and replacing it with two high quality layers. First layer, binder course, was made of high stiffness modulus asphalt concrete and second, wearing course, was made of SMA. In both mixes, the traditional bitumen was replaced by polymer modified bitumen. This technology was applied on several Warsaw streets, however prediction is based upon five of them. First part of paper was formed on basis of conclusions made during the technological supervision. It consists in assessment of correctness of repair as regards workmanship and quality of used materials. In IBDiM, at recipe designing stage, basic physical characteristics and mechanical characteristics of bituminous mixtures (visco-plastic deformation resistance, fatigue resistance and complex stiffness modulus) were examined. During paving, control testing of composition of bituminous mixes was carried out. In second part of paper, deflections before and after renewal, measured by Falling Weight Deflectometer FWD, were compared. Next, construction durability was calculated by using mechanistic designing method and fatigue criteria, as well. Modulus of the layers was obtained from field and laboratory measurement. Another stage of the thesis was to predict heavy vehicle traffic intensity in future time on the chosen streets. Finally, calculated pavements bearing capacity and predicted heavy traffic intensity were equated. In this way, durability of reconstructed pavements was obtained. On the basis of all laboratory tests and calculations, it was affirmed, that pavement renewal assure better predicted durability then traditional pavement repair. In spite of less work expenditure, less cost and time, obtained predicted durability was similar to durability of overhaul. (Author/publisher)
Abstract