同步碎石封层桥面防水黏结层温度敏感性研究

On Modified Temperature Model for Synchronous Chip Seal Waterproof Binder Course on the Concrete Bridge

为使水泥混凝土桥面碎石封层防水黏结层在不同温度下的黏结强度和抗剪强度有可比性,首先采用温度模型对气温、桥面及防水黏结层温度差异性进行对比;其次,对该防水黏结层强度最大化配比设计及其黏结、抗剪强度对不同温度条件敏感性进行分析。研究表明:1.2 kg/m2SBS改性沥青与8 kg/m2 7～9.5 mm碎石时防水黏结层强度最大;黏结层、桥面温度分别平均高出气温10℃、17℃,层间强度对温度极为敏感,同一气温对应的黏结层温度以及桥面温度下检测的强度下降38%～80%,应采用防水黏结层温度作为检测温度。最后,回归防水黏结层黏结、直剪、扭转剪切强度的理论模型,提出Ki强度修正系数,并通过建立P25强度修正模型将不同温度下强度换算成25℃标准强度值。

To make bonding and shear resistance strength of synchronous chip seal waterproof binder course under different temperature comparable,the difference of air temperature,deck and waterproof binder course temperature,the design of waterproof binder course and the sensitivity of the strength to the different temperature was studied.It showed that the strength was maximal when asphalt and chip is 1.2 kg/m2 and 8 kg/m2;the strength between courses was sensitive to the temperature and the detected strength under the binder temperature and deck temperature corresponding to the same reduced by 38% to 80%,therefore the strength should be detected under the waterproof binder course temperature.Finally,the correlation coefficient R2 of calculation model of the binder,direct,torsion strength established was above 0.94;After regressing theoretical model of binding,direct shear,and torsion shear intensity of waterproof bingder course,modified coefficient Ki was proposed;the strength under different temperature could be converted to the standard strength below 25℃ by the establishing of P25 modified model of the temperature.