基于混凝土绝热温升新模型分析大体积高强混凝土水化热效应

Analysis of Hydration Heat Effect of Large Volume High-Strength Concrete Based on a New Model of Concrete Adiabatic Temperature Rise

绝热温升模型是大体积混凝土水化热效应分析的最重要参数之一。本文根据混凝土所用水泥以C3S、C2S两种水化活性组分为主的特点,提出了考虑C3S与C2S水化反应速率差异的混凝土双项线性叠加多参数指数函数绝热温升模型。开展了一种普通高强C50混凝土和另一种高性能C60混凝土的绝热温升试验,将双项叠加式新模型、传统单项指数函数模型与试验结果对比,结果表明新模型与试验结果拟合更好。将新旧模型用于某桥墩身大体积混凝土水化热有限元建模分析中,并与实测温度变化过程进行比较。对比结果显示,运算分析所得的温度变化趋势与实测所得温度变化趋势吻合度较好,整体误差值控制在0.1℃~2.97℃之间,在快速放热阶段能较好地反应拱脚结构的实际升温情况。

The adiabatic temperature rise model is one of the most important parameters for analyzing the hydration heat effect of large volume concrete. This article proposes a concrete binomial linear superposition multi parameter exponential function adiabatic temperature rise model that takes into account the difference in hydration reaction rates between C3S and C2S, based on the characteristics of C3S and C2S as the main hydration active components in cement used in concrete. We conducted adiabatic temperature rise tests on one type of ordinary high-strength C50 concrete and another type of high-performance C60 concrete. The new dual term superposition model and the traditional single exponential function model were compared with the test results, and the results showed that the new model fits better with the test results. We apply the new and old models to the finite element modeling and analysis of the hydration heat of large volume concrete in a certain bridge pier body, and compare it with the measured temperature change process. The comparison results show that the temperature change trend obtained from the calculation analysis is in good agreement with the measured temperature change trend, and the overall error value is controlled between 0.1˚C and 2.97˚C. It can better reflect the actual heating situation of the arch foot structure in the rapid heat release stage.