基于半绝热法的现场大体积混凝土水化热预测方法研究

Research on the Prediction Method of Hydration Heat of Mass Concrete On-Site Based on the Semi-Adiabatic Method

摘要: 在大体积混凝土施工过程中，控制浇筑时的水化热是确保施工质量的关键步骤。目前，主要通过有限元仿真计算来模拟浇筑过程中体系温度的变化。然而，有限元分析得到的模拟数据与实测数据存在较大差距，只能通过后期调整有限元模型的参数来逼近实测数据，无法有效指导施工。为了解决这一问题，本文提出了一种基于半绝热法的现场大体积混凝土水化热预测方法。利用自制的简易水化热测试装置测定实际配合比下混凝土的绝热温升曲线，通过推导得到修正的热源函数模型，并结合实验室标定的水泥水化过程中导热系数函数的时变模型，对有限元分析模型进行修正，使其更加符合实际情况，更贴近实测水化热数据。通过实际工程案例的实测数据与有限元模拟结果的分析，发现此方法可以有效减少有限元模拟结果与实测数据的误差，更有效地指导现场施工，对于控制大体积混凝土水化热引起的温度应力裂缝具有重要意义。

Abstract: Controlling the hydration heat during the pouring of mass concrete is a crucial step to ensure construction quality. Currently, finite element simulation is primarily used to model the temperature variations during the pouring process. However, significant discrepancies often exist between the simulated data from finite element analysis and the actual measured data. These discrepancies can only be minimized by post-adjustment of the finite element model parameters, which is insufficient for effective construction guidance. To address this issue, this paper proposes an on-site prediction method for the hydration heat of mass concrete based on the semi-adiabatic method. A self-made, simple hydration heat testing device is used to determine the adiabatic temperature rise curve of concrete with the actual mix proportions. By deriving a corrected heat source function model and integrating a time-varying thermal conductivity function model calibrated in the laboratory during the cement hydration process, the finite element analysis model is adjusted to better align with real conditions and closely match the measured hydration heat data. Analysis of measured data from practical engineering cases and finite element simulation results demonstrates that this method effectively reduces the error between simulated and measured data. It provides more reliable guidance for on-site construction and is significant for controlling temperature-induced stress cracks in mass concrete due to hydration heat.