Preparation and thermal cross-linking mechanism of co-polyester fiber with flame retardancy and anti-dripping by in situ polymerization

Scheme of proposed thermal cross-linking mechanism.

Effect of aging on low-temperature crack resistance and water stability of polyester fiber asphalt mixture

In order to study the influence of different aging conditions on the low-temperature crack resistance and water stability of polyester fiber asphalt mixture. Prepare standard Marshall specimens of asphalt mixture with 0.4 % polyester fiber doping, and carry out water immersion Marshall test and low temperature splitting test through indoor asphalt mortar aging, asphalt mixture short-term aging and long-term aging. The results show that: under the three aging conditions, when the water immersion and low temperature time are fixed, with the increase of the aging degree, the water stability and low temperature crack resistance of the asphalt mixture decrease. When the immersion time is 2 h, the stability of asphalt mortar aging and short-term aging decreases by 6.0% and 11.8%, respectively, compared with unaging, but the long-term aging is only 3.6% lower than the short-term aging. When the temperature is -5℃, the split tensile strength of asphalt mortar aged and short-term aged increases by 4.24% and 14.35%, respectively, compared with unaging, while long-term aging only increases 4.18% compared with short-term aging. This indicates that the short-term aging condition has the most significant effect on the water stability and low-temperature crack resistance of polyester fiber asphalt mixes. At the same time, this study established a regression equation between the test temperature and the low temperature evaluation index through quadratic fitting (the correlation coefficient is 0.960-0.998), and the regression relationship can be used to estimate the low temperature evaluation index at different test temperatures.

Viscoelastic Mechanical Model of Asphalt Concrete Considering the Influence of Characteristic Parameter of Fiber Content

This paper carries out bending creep tests on polyester fiber-reinforced asphalt concrete beams, and investigates how the volume ratio and aspect ratio of the fibers influence the parameters of viscoelastic mechanical model and the viscoelastic performance of the asphalt concrete. The results show that: with the growing volume ratio and aspect ratio of the fibers, the midspan deflection and bottom flexural-tensile strain of asphalt concrete beams first dropped and then rose over time; the characteristic parameter of fiber content (FCCP) could reflect the overall effects of the volume ratio and aspect ratio of the fibers. On this basis, a viscoelastic mechanical model was established for the asphalt concrete in the light of the influence of FCCP. The test and theoretical results show that, in our tests, the optimal volume ratio of fibers, optimal aspect ratio of fibers, and optimal FCCP are 0.348, 324, and 1.128 for polyester fiber-reinforced asphalt concrete.

Experimental Performance of Polyester-Fiber-Based Soil Geogrids against Reflective Cracks

Road pavements may be subjected to deterioration problems caused by excessive traffic loads, thousands of load repetitions, environmental and climatic conditions, freeze-thaw effects, and insufficient design of mixtures. The formation of reflective cracks is the most common structural problem that occurs on a road’s superstructure over time. Special applications requiring expensive geosynthetics, such as glass-fiber-based geogrids (GG) or carbon-fiber-based geogrids, are generally used to solve this problem. Therefore, in this study, the utility of polyester-fiber-based soil geogrid (PG) is investigated as an alternative solution in relation to experimental performance analysis. Three-point bending tests are realized to custom-engineered hot mix asphalt plate specimens, with and without geogrids, under full-capacity static loading, cyclic loading, and dynamic fatigue loading conditions. Although the same bending strength levels are seen for plate specimens, including GG and PG reinforcements with a 100 kN/m tensile strength, PG-containing specimens show a 42% greater performance in the case of cyclic loading. Moreover, PG-reinforced plates have greater elastic behavior than GG plates, up to 49.4% within a dynamic fatigue test at the end of 15,000 cycles. As a result, it is shown that reflective cracks can be more effectively delayed by the use of soil PGs, rather than GGs, in relation to overall performance and service life.