Yan Chen,Jianying Hu,Xiaonan Wu,Shaochan Duan,Hongyu Wang,Tao Ma
Service life of traditional steel bridge deck pavement is significantly shortened due to the failure of waterproof adhesion. To improve the interlayer bonding performance and extend its service life, polyurethane is proposed as a waterproof adhesion layer (WAL) for a steel bridge deck. This study aims to synthesize polyurethane WAL by free radical solution polymerization under different types and dosages of crosslinking agents as well as the mixing ratio of an acrylic co-blend. Tensile properties, water resistance, glass transition temperatures, thermal stability, and adhesive strength of the polyurethane binder are evaluated. The results demonstrate that polyurethane WAL yields desirable performance by using a hydroxyl molar ratio of 1/3 and an acrylic co-blend of 65%. Specifically, the tensile strength and breaking elongation of polyurethane WAL reach the maximum values of 6.466 MPa and 268.4%, respectively. The water absorption rate of polyurethane WAL is less than 4%. Glass transition temperatures of polyurethane WAL are between −80 °C and 60 °C, respectively. Polyurethane WAL features remarkable high- and low-temperature performance and thermal stability. Finally, adhesion strength between polyurethane WAL and the steel plate reaches up to 5.21 MPa. The outcome of this study facilitates the design and application of polyurethane waterproofing adhesion layers for steel bridge decks.
Shaochan Duan,Xiaonan Wu,Hongyu Wang,Jianying Hu,Yingcheng Luan,Tao Ma
To enhance the environmental sustainability and pavement performance of steel bridge deck paving, a novel semi self-compacting cold mix polyurethane mixture (CMPU-10) for steel bridge deck paving was specifically designed and evaluated. Herein, this study presents the first comprehensive documentation of the research process involved in the mix design of CMPU-10. Initially, based on the theory of maximum density curve, a gradation with a Talbot index ( n ) of 0.40 was identified as the preliminary gradation for designing CMPU-10 by void ratio, compressive strength and slump tests. Subsequently, the aggregate grade-by-grade filling test revealed the critical influence of sieve sizes (0.075 mm, 0.6 mm, and 2.36 mm) on the mixture dense degree. From these findings, an in-depth analysis of the effects of aggregate passage under the key sieve on the degree of mixture density, compressive strengths, and flow properties led to the determination of the gradation range of CMPU-10. The optimum binder-aggregate ratio for the median gradation was determined to be 9.2%. Finally, wheel tracking, semi-circular bending (SCB) and freeze-thaw splitting tests showed that the designed CMPU-10 exhibits superior high-temperature stability performance, low-temperature cracking resistance and moisture susceptibility compared to the TAF epoxy asphalt mixture (EA-10). This paper not only provides a new potential low-carbon material for steel bridge deck paving projects, but also establishes a theoretical foundation for the optimization design and promotion polyurethane mixture.
危险品化学品经营许可证（带存储）