STUDY OF THE HYDRATION PRODUCTS OF MIXTURES OF CEMENT AND ASPHALT EMULSION USED IN RECYCLING WORKS OF FLEXIBLE PAVEMENTS

摘要

The method of recycling of flexible pavements with cement or with bituminous emulsion and cement is finding increase use in cases of rehabilitation of old flexible pavements needing improvement not only of their functional but also of their structural characteristics. These recycling methods are recognized for their contribution to the sustainable development. In this work the results of a study of the hydration products of mixtures of cement and of bituminous emulsion and cement used in recycling works are presented. Mixtures of cement and bituminous emulsion in various percentages as well mixtures of a) aggregates with cement and b) aggregates and combinations of bituminous emulsion and cement are analysed in order to study the hydration products and the cohesion characteristics between ⅰ) cement and aggregates ⅱ) cement and bitumen and ⅲ) cement and aggregates in presence of bitumen. For this purpose X-ray Diffraction, Optical Microscopy and Scanning Electronic Microscopy analysis are used. It is found that the bituminous emulsion is not prohibiting the hydration cement but is delaying it. It seems also that the cohesion characteristics between hydration products and bitumen, and/or aggregates is not impaired by the presence of bitumen.