Research On Laboratory Test Of Pavement Performance On Micro-surfacing Mixture

Now the society requires the road condition to be high quality considering the increase of traffic volume and heavy vehicles, the fact of over-loading and heavy-loading, and vehicles channelized. However, asphalt pavements are considerably sensitive to temperature, rainfalls and sunlight. Its comparatively low bearing capacity, anti-disease and anti-water disaster capacity is critical towards the serviceability and durability. Currently the most frequently used idea in China to solve this problem is to first miling-planing the asphalt surface and further cover it with the hot-mix bituminous concretes. While in developed countries in Europe and US, micro-surfacing is widely used as preventive maintenance, this in our country is mostly used for maintaining the traditional overlays. As a new technique, micro-surfacing is definitely in demand of far more research in China.Firstly, the preparation mechanism of modified emulsified bitumen and process and tips for preparing modified emulsified bitumen in laboratory is introduced.Secondly, experimental investigations are proceeded towards raw materials of micro-surfacing and the effects of emulsifier, asphalt products,asphalt-aggregate ratio towards the performance and storage stability of evaporation residue of modified emulsified asphalt. With increase of modified emulsified asphalt, the low and high temperature function ability is effectively improved, however, the improving margin is diversified based on the difference of base asphalts.Thirdly, we studied the mixture design and the pavement performance in which we analyzed technical requirements of raw micro surfacing materials of the ISSA, relevant performance test and the mixture design process. The main problem of traditional design and evaluation method of ISSA is that the asphalt aggregate ratio is too large determined by the wet track abrasion and loading wheel test. In this paper, we applied the"mass loss"of raveling test and the improving adhesion amount of sand to determine the optimal asphalt content. Aiming at anti-slide performance and anti-seepage performance in pavement performance we measured the texture depth and water permeability coefficient.Finally, we researched on interlaminar shear strength between the micro surfacing and pavement using the determined gradation and the optimum emulsified asphalt content. These studies contain the situation and the gradation of substratum, the usage of penetrtion-grade bitumen, thickness of micro surfacing and the key aspects obtained by with the gray entropy method.