Semi-flexible material: The sustainable alternative for the use of conventional road materials in heavy-duty pavement

Abstract

Semi-flexible material is a composite pavement surfacing that uses both asphalt concrete (AC) with a unique structure and Portland cement concrete (PCC) in the same layers. The AC introduced in this kind of pavement is initially designed with the air-void content in the range of 25–35%, while the grout of Portland cement is the mixture of Portland cement, silica fume, silica sand, water and a suitable amount of plasticity additive. The process of producing and pouring cement grout into AC layers is conducted when AC layers are totally cool down, which is estimated at least 24 h after finishing the last rolling. Semi-flexible material is believed to have a better rutting resistance compared to that of the conventional AC, this is resulted from the appearance of cement grout. Furthermore, joints are not required in this kind of pavement. As the results, the significant advantages of the material are the combinations of those of AC and PCC. In this paper, the authors intend to access the rutting and indirect tensile strength of this material. The applications of semi-flexible material in the pavements of airport, airfield, port, warehouse and other high traffic areas are feasible.