| Cement stabilized gravel material has been widely used in semi-rigid base pavement structure,and its characteristics such as good stability,high strength and strong rigidity are well received.However,due to the characteristics of the graded crushed stone material,the semi-rigid base layer usually presents difficult-to-solve cracking problems under the effect of the external environment and load.The occurrence of cracks in the semi-rigid base layer tends to produce reflective cracking,which affects the overall pavement structure bearing capacity and continuity as well as the service level of the road.In this paper,in order to improve the mechanical properties of the graded aggregates,different materials and different contents of fiber materials are added to the graded aggregates,and the mechanical properties such as shear strength and splitting strength are tested and the performance tests are performed.The construction technology and corresponding economic benefits of fiber grade aggregates were studied and analyzed.The main results are as follows:It was found through the split test that the addition of fibers constitutes an internal network structure to enhance its crack resistance.With the same fiber content,the polypropylene fibers increase the splitting strength up to 44%.(2)Through indoor shear tests,it was found that fibers mixed in the mix can play a reinforcing role similar to reinforcing bars,and can increase the gripping force on the aggregate particles,thereby greatly increasing its shear resistance.strength.(3)Through comparative study and analysis of the effect of the added fiber on the rutting resistance of graded crushed stone and the effect of laying geogrid on the rutting resistance of graded crushed stone,it was found that 1% of polypropylene fiber was added to the graded crushed stone material.It will significantly improve the anti-rutting ability of the road surface;(4)From the control of raw materials to the requirements of on-site construction,the technical requirements and on-site quality control of fiber grade aggregates were proposed,and the important links that need special attention during construction were pointed out,which was a high-quality construction of fiber grade aggregates Provide technical support and basis.(5)Compared with the semi-rigid base layer,the flexible base layer of fiber grade gravel has obvious direct benefits,and the use of a fiber grade gravel flexible base can reduce road maintenance,maintenance costs and user costs,and the number of rebuilds is significantly reduced. |
