Research And Application On High-performance Pouring Semi-flexible Pavement Material

Semi-flexible pavement is a new kind of rigid and flexible pavement,which is formed by filling the special cement slurry into the big-interspaced asphalt mixture.The semi-flexible pavement has the higher character of flexibility than the cement concret pavement and the higher character of rigidity than bituminous concrete pavement,absorbs advantages of the two tranditional pavements.The semi-flexible pavement has been widely used in Japan,America and Europe,but still in experimental stage in our country.There are many reasons such as,pouring cement slurry can not be meeted the requirements for permeability and shrinkage,compatibility is not good on the interface of asphalt and cement slurry.Thereupon semi-flexible pavement is not adequately researched and of extensive application.So futher study on the semi-flexible pavement is necessary.Against these problems,this paper does the following works and has obtain many important results.The paper studies and reveales the interactivity among components by analysing composition of structure,explaining the mechanism of strength formation on semi-flexible pavement material and its controlling factors,which can provide theoretical basis for design and preparation of the semi-flexible pavement material.A master factor to performance of the semi-flexible material is the performance of the cement slurry.The paper discusses the rheologic behavior of the cement slurry on the interface of asphalt,and raising a method that adding a little matter which can increase the permeability of the cement slurry and another proper matter which can offset shrinkage of the cement slurry can prepare the cement slurry with higher permeability and lower shrinkage.The paper reseaches the basic asphalt mixture's charactics of the volume parameter which how to influence the performance of the semi-flexible pavement material.Numerous experiment show that the smaller void of the basic asphalt mixture,the better low-temperature resistance,the bigger void of the basic asphalt mixture,the better high-temperature stability and water stability.With the same void,continuous- apertura structure'smi-flexible pavement material has more better mechanical property and pavement performance,the reason is that the interlocking force between cement-stone and basic asphalt mixture of continuous- apertura structure'semi-flexible pavement material is bigger than umiform-aperura structure'semi-flexible pavement material.On accoant of the easy cracking of the semi-flexible pavement,by studing the mechanism of the cracking on the semi-flexible pavement,the result shows most crackings firstly create at the interface between the basic-asphalt mixture and cement-stone,expanding among the interface.In order to decrease the generation of crackings or release expanding of the cracking,the paper proposes a improving measure which is to use modified asphalt binder with high viscosity.Based on the previous research on the relertionship of proportioning,structure and performances,the paper gives the construction method of semi-flexible pavement and quality controling standards according the practical experience.Finally,the trail pavement had be successfully constructed based on the trail project in Wuhan to Yingshan expressway.