温升抑制剂对施工期渡槽温控防裂影响的有限元分析

Finite element analysis of the influence of temperature rise inhibitor on temperature control and crack prevention of aqueduct during construction

由水化反应导致的非均匀温度场,在受到结构自身约束时,将会产生较大的温度应力和温度裂缝。本文主要研究水化热温升抑制剂作为一种潜在的、便捷的、经济的渡槽温控外加剂的可行性。通过拟合不同温升抑制剂掺量的混凝土热力学试验数据,建立渡槽有限元模型,模拟施工期渡槽温度场和应力场。研究发现,当温升抑制剂掺量为胶凝材料质量的0.6%时,渡槽的温度和应力峰值明显降低,降低幅度分别25.3%和26.0%,具有很好的温度控制防裂效果。而当温升抑制剂掺量较少时,温控防裂效果较差。随着结构厚度的增加,温升抑制剂降低温度峰值的效果逐渐降低,但仍超过20.0%,应力峰值降低幅度均超过26.0%。随着结构长度的增加,温升抑制剂降低应力峰值的效果有逐渐增加的趋势。

The non-uniform temperature field caused by the hydration reaction will generate significant temperature stresses and temperature cracks when subjected to structural constraints.This paper primarily investigates the feasibility of using a hydration heat temperature rise inhibitor as a potential,convenient,and cost-effective additive for temperature control in aqueduct construction.By fitting thermodynamic test data of concrete with different proportions of the temperature rise inhibitor,a finite element model of the aqueduct is established to simulate the temperature and stress fields during the construction period.The study finds that when the proportion of the temperature rise inhibitor is 0.6% of the mass of cementitious materials,the peak temperature and stress of the aqueduct are significantly reduced by 25.3%and 26.0%,respectively,demonstrating a good temperature control and crack prevention effect.However,when the proportion of the temperature rise inhibitor is lower,the effect of temperature control and crack prevention is not as significant.With an increase in structural thickness,the temperature rise inhibitor’s ability to reduce the peak temperature gradually decreases but remains above 20.0%,and the reduction in stress peak is still over 26.0%.With an increase in structural length,the effect of the temperature rise inhibitor in reducing the stress peak tends to increase.