Characteristics of polyester

The objective of the present study was to investigate the engineering characteristics of polyester-reinforced cement-stabilized macadam (PETCSM). Shrinkage and mechanical tests were performed to analyze the water loss rate, shrinkage coefficient, compressive strength, cleavage strength, and compression rebound modulus of PETCSM as functions of the age and fiber content of the material. An optimum fiber content of PET was proposed. The effects of PET were compared with those of polypropylene (PP) fibers. As the fiber content increased, the water loss rate of PETCSM decreased and then increased, with the minimum water loss occurring at a fiber content of 0.7‰. The shrinkage coefficient of the PETCSM gradually decreased as the fiber content increased, with the critical point of zero shrinkage appearing when the fiber content reached 0.7‰. The PET fibers had a greater effect on enhancing the mechanical performance of the CSM than did the PP fibers. The strength of the PETCSM was primarily affected by the maturity of the hydration reaction, by active enhancement effects, and by the passive blocking effects of the fibers. The strength was also affected by the fiber age and fiber content. The cleavage strength was more sensitive to the fiber content than was the compressive strength. The addition of PET altered the elastoplastic behavior of the PETCSM and significantly decreased shrinkage in the CSM. The optimum fiber content in the PETCSM is 0.7‰. The PETCSM has better engineering properties than CSM without fiber. This paper may provide a solid theoretical foundation for the widespread use of PETCSM in engineering applications.