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通过铺筑足尺水泥混凝土路面,在连续观测混凝土板不同深度早龄期温度场的同时,基于自主开发的竖向变形观测装置观测了端部自由板和内部约束板在整个早龄期的竖向翘曲变形历史。在此基础上推导了基于五测点的等效线性温度梯度计算公式,提出了基于板的翘曲变形时程和温、湿度时程的水泥混凝土路面板硬化翘曲直接量测方法,为硬化翘曲存在形态的试验量测提供了一种新的分析方法。分析表明:端部自由板翘曲变形幅值(-0.3~1 mm)远高于内侧完全约束板的相应位置(-0.2~0.3 mm)。受约束程度、湿度梯度、温度梯度等因素的影响,板的翘曲呈现显著的非对称性。约束稳定区域等效线性温度梯度随龄期逐渐衰减和稳定至1℃/m,自由板边与自由板角等效内嵌温度梯度时变规律多样。水泥混凝土路面板等效内嵌温度梯度主要集中在-25~25℃/m范围内,约占水泥混凝土路面设计所采用温度梯度的25%,不可忽略,但具体幅值需依据具体路面结构、板块尺寸、早龄期温湿度历史以及混凝土材料性能等因素通过计算或现场实测进行评估。
By paving full-scale cement concrete pavement, while continuously observing the temperature field of early age at different depths of concrete slab, vertical self-developed deformation observation device was used to observe the vertical freeboard and internal restraint plate at the early age Warp deformation history. On this basis, the calculation formula of equivalent linear temperature gradient based on five measuring points is deduced, and the direct measurement method of the hardening and warping of cement concrete pavement slab based on warping deformation time history, temperature and humidity time history is proposed. Existence of morphometric test provides a new analytical method. The analysis shows that the warp deformation amplitude (-0.3 ~ 1 mm) of the end free plate is much higher than the corresponding position (-0.2 ~ 0.3 mm) of the fully restrained plate inside. Due to the restraint degree, humidity gradient, temperature gradient and other factors, the warpage of the panel shows significant asymmetry. The equivalent linear temperature gradient in the stable region of constraint is gradually decayed and stable to 1 ℃ / m with age, and the equivalent temperature gradient of the free plate and the free slab angle are various. The equivalent embedded temperature gradient of cement concrete pavement is mainly concentrated in the range of -25 ~ 25 ℃ / m, accounting for about 25% of the temperature gradient used in cement concrete pavement design. The specific amplitude should be based on the concrete pavement structure, Plate size, temperature and humidity history of early age and concrete material properties and other factors by calculating or field measurement to assess.