Using case study on the performance of rural cement stabilizing construction waste recycling road base

Abstract

In order to solve the problem of resource utilization of construction waste (C&W) recycled aggregate (RA) in rural road grassroots, natural aggregate (NA) was replaced by RA with 0%, 20%, 40%, 60%, 80% and 100% in the test. The unconfined compressive strength, splitting strength, compressive resilience modulus, dry shrinkage test, and frost resistance test were used to test the road performance of the recycled mixture. In order to improve the strength and crack resistance of cement stabilized regenerated mixture, three different admixtures (polypropylene fiber, expansion agent, and curing agent) were considered based on the orthogonal test to improve the crack resistance of the regenerated mixture, and their influence weights were analyzed. Relying on the Gaobeidian rural road network reconstruction project, the construction waste recycling test road was laid, and the construction quality of compaction, bending, and flatness was tested. The results show that the strength of cement-stabilized recycled mixture peaks when RA content is 20%. When RA content is 0% to 100%, the compressive strength decreases by 22.6%, compressive resilience modulus decreases by 18.7%, and tensile strength decreases by 33.2%. Adding 0.8‰ polypropylene fiber, 0.4% expansion agent, and 1.5% curing agent increased 21.2% 7d unconfined compressive strength, 7.8% in 7d splitting strength, and 43.2% in 14d drying shrinkage coefficient. The construction test results show that adding fiber and low-content construction waste increases the base load capacity, increases the compressive strength by 34.5%, reduces the base deflection by 10.5%, and has good road performance. Finally, considering the test results comprehensively, when the RA content is below 20%, and the polypropylene fiber content is between 0.6‰ and 0.8‰, it can meet the basic construction requirements of secondary and sub-secondary rural regeneration roads in China.