The built-in temperature difference (BITD), defined as the temperature difference between the top and bottom of a slab at the final setting time, is an important parameter for analysing curling stress and slab deformation in concrete pavements. However, the available methods for estimating this parameter are very limited. A method to predict the BITD in a concrete pavement was therefore developed. To do this, a numerical model was developed to predict the temperature distribution in a concrete slab at early age using a transient one-dimensional finite-difference method. A mathematical equation for predicting concrete final setting time presented in the literature was used and incorporated in the numerical model to predict the BITD. The results of the numerical model showed good agreement with field data. Using the proposed model, the effects of climatic conditions, placement time, pavement thickness and concrete mix proportion on the BITD were also evaluated. The results showed that climatic conditions, placement time and concrete mix proportion have substantial effects on the BITD, whereas pavement thickness has only a slight effect. The proposed model can be used to predict the BITD in concrete slabs for given concrete mix design, placement time, pavement thickness and environmental conditions.

中文翻译：

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一种预测混凝土路面内置温度的机械方法

内建温差 (BITD)，定义为终凝时板坯顶部和底部之间的温差，是分析混凝土路面卷曲应力和板坯变形的重要参数。但是，用于估计此参数的可用方法非常有限。因此开发了一种预测混凝土路面 BITD 的方法。为此，开发了一个数值模型来使用瞬态一维有限差分方法预测早期混凝土板中的温度分布。文献中用于预测混凝土最终凝结时间的数学方程被使用并结合到数值模型中以预测 BITD。数值模型的结果与现场数据显示出良好的一致性。使用建议的模型，还评估了气候条件、铺设时间、路面厚度和混凝土配合比对 BITD 的影响。结果表明，气候条件、浇筑时间和混凝土配合比对BITD有显着影响，而路面厚度的影响很小。所提出的模型可用于在给定的混凝土配合比设计、浇筑时间、路面厚度和环境条件下预测混凝土板的 BITD。