沥青路面路表弯沉温度及湿度修正系数的定量化探讨

Quantitative Discussion of Temperature and Humidity Correction Factors for Surface Deflection of Asphalt Pavements

路表弯沉值是反映路面整体承载能力的关键指标,温、湿度系数的合理修正是准确评定路表弯沉的重要保障。针对现有规范《公路工程质量检验评定标准第一册土建工程》(JTG F80/1—2017)和《公路沥青路面设计规范》(JTG D50—2017)在评定沥青路面弯沉时,对温、湿度修正系数的确定存在主观性及指导性不足的问题,通过借鉴贝克曼梁法温度修正模型、调查路基平衡湿度状况以及利用路基回弹模量值与路基饱和度关系模型,提出了沥青面层中点温度、平衡湿度状态下路基回弹模量和检测时路基回弹模量的取值方法,并进一步计算出温、湿度修正系数。结果表明:1)通过调查路基填料和路基干湿状态,并利用相关模型,可实现沥青路面路表弯沉温、湿度修正系数的定量化确定;2)计算出的修正系数可消除温、湿度对实测路表弯沉值的影响,可用于实际沥青路面弯沉的验收评定。

Road surface deflection is the key index to reflect the overall bearing capacity of the pavement,temperature and humidity coefficient of reasonable correction is an important guarantee for accurate assessment of road surface deflection.When assessing the surface deflection of asphalt pavement in the existing Inspection and Evaluation Quality Standards for Highway Engineering Section 1 Civil Engineering(JTG F80/1-2017)and Specifications for Design of Highway Asphalt Pavement(JTG D50-2017),the determination of temperature and humidity correction coefficients is subjective and lacks guidance.By learning from the temperature correction model of the Beckman beam method,investigating the equilibrium humidity condition of the roadbed and utilizing the relationship model of the roadbed resilience modulus value and the saturation of roadbed,a reasonable correction model is proposed,the method of taking the value of roadbed resilience modulus under the mid-point temperature of the asphalt surface layer,equilibrium humidity condition and roadbed resilience modulus at the time of testing is proposed,and the correction coefficients of temperature and humidity are further calculated.The results show that:1)The quantitative determination of temperature and humidity correction coefficient of the deflection of asphalt pavement surface can be realized by investigating the roadbed filler and the dry and wet state of the roadbed and through relevant model;2)The calculated correction coefficient can eliminate the influence of temperature and humidity on the measured deflection value of the roadbed surface,which is of great significance in accurately evaluating the surface deflection of asphalt pavement.