Conventional pavement materials like SMA and GA do not meet the requirement for steel bridge decks. Epoxy asphalt concrete (EAC) has good performances but also has fatigue problems stemming from their inherent chemical structures, which, in some cases, led to short service life. Herein, we report a polyurethane concrete (PUC) consisting of a one-phase tough polyurethane binder as the matrix and dolerite aggregates as filler. First, PUC samples are prepared by mixing liquid reactants like polycarbonate diol, aliphatic isocyanate and glycerine with dolerite aggregates. The optimum formula of the PUC (binder-aggregate ratio of 8.5%) is determined by the Marshall stability and compressive strength tests. Second, Hamburg wheel tracking, freeze-thaw splitting, low temperature bending and linear contraction coefficient measurements are conducted on the PUC samples. Test results show that PUC composites have strong low-temperature toughness (the flexural strength 24.3 ± 1.3 MPa and flexural strain of 7020*10−6 at −10°C) and high dynamic stability (153,000 cycles/mm, about as 5 times as epoxy asphalt concrete (EAC). The alkaline hydrolysis tests show PUC has excellent durability (remained strong after 24 days of hot alkaline water treatment). These results support PUC is a promising material for bridge deck pavement.
Modified emulsified asphalt is widely applied as a waterproof adhesive layer for bridge decks. However, the increasing prevalence of deck distress indicates that conventional formulations cannot satisfy the stringent durability requirements under complex service conditions. To overcome these limitations, a polymer-composite multi-component modified emulsified asphalt (PCMEA) binder with superior waterproofing and adhesion was developed. The modification mechanism was investigated using scanning electron microscopy (SEM), energy-dispersive spectroscopy (EDS), fluorescence microscopy (FM), and Fourier transform infrared spectroscopy (FTIR), while hydrophobic characteristics were analyzed via 3D confocal imaging, SEM, and contact angle measurements. Results indicate that waterborne epoxy resin (WER) and waterborne polyurethane (WPU) form an interpenetrating polymer network through hydrogen bonding and molecular diffusion, integrating epoxy rigidity with polyurethane flexibility. The synergistic effects of poly(trifluoropropylmethylsiloxane) (PF), silica (SiO₂), and glass fiber (GF) further enhance surface energy regulation, mechanical strength, and toughness. PCMEA exhibits significantly improved hydrophobicity, with no water penetration under 0.3 MPa pressure. Mechanical tests confirm its high bonding strength, thermal stability, frost resistance, and corrosion resistance. This study elucidates the modification mechanism of polymer-composite emulsified asphalt and provides a feasible strategy for developing high-performance waterproof adhesive materials, offering valuable implications for extending bridge deck durability and mitigating pavement distresses.
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）