寒区钢桥面超高性能混凝土铺装层层间剪切强度研究

Study on interlayer shear strength of ultra-high performanceconcrete pavement for steel bridge deck in cold region

为了避免发生寒冷地区沥青面层与超高性能混凝土(UHPC)层结合不良导致的沥青面层滑移或脱落现象,对钢桥面UHPC铺装层层间剪切性能进行研究。考察涂布环氧树脂防水粘结层的成型试件分别在不同涂布厚度、不同温度、不同浸泡溶液条件下,经冻融循环后的抗剪强度变化规律,并依托实际工程对层间剪切强度进行数值模拟分析。结果表明:环氧树脂防水粘结层的最佳涂布量为0.4 kg/m^(2);其抗剪强度随着温度的增大而减小,在60℃时抗剪强度能达到1.8 MPa,高温性能良好;盐溶液环境下的冻融循环对强度的损伤大于清水环境下的损伤;数值模拟得到最不利位置剪切应力峰值远小于试验得到的环氧树脂防水粘结层抗剪强度,环氧树脂防水粘结层性能优异。研究得到的UHPC铺装层层间剪切强度规律可为延长钢桥面使用寿命提供理论依据。

In order to avoid the occurrence of slip or detachment of asphalt surface layer caused by poor bonding between asphalt surface layer and UHPC layer in cold regions,the interlayer shear performance of steel bridge deck ultra-high performance concrete(UHPC)pavement was studied.The change rule of the shear strength of the formed specimens coated with epoxy resin waterproof adhesive layer was investigated under different coating thickness,different temperature and different soaking solution conditions after freeze-thaw cycle.Numerical simulation analysis of interlayer shear strength was conducted based on actual engineering.The results show that the optimal coating amount of epoxy resin waterproof bonding layer is 0.4 kg/m^(2);Its shear strength decreases with the increase of temperature,reaching 1.8 MPa at 60℃,indicating good high-temperature performance;The damage to strength caused by freeze-thaw cycles in salt solution environments is greater than that in clear water environments;The peak shear stress at the most unfavorable position obtained from numerical simulation is much smaller than the shear strength of the epoxy resin waterproof bonding layer obtained from the experiment,indicating excellent performance of the epoxy resin waterproof bonding layer.The obtained interlayer shear strength law of UHPC pavement can provide a theoretical basis for extending the service life of steel bridge decks.