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Deterioration of concrete due to ASR: Experiments and multiscale modeling
Cement and Concrete Research ( IF 11.4 ) Pub Date : 2021-08-24 , DOI: 10.1016/j.cemconres.2021.106575
Tagir Iskhakov 1 , Colin Giebson 2 , Jithender J. Timothy 1 , Horst M. Ludwig 2 , Günther Meschke 1
Affiliation  

The process of ASR (Alkali-Silica Reaction) induced expansion and damage in pavement concrete specimens is investigated using laboratory experiments and computational modeling. In the experimental program, the concrete specimens are subject to CS-CPT (climate simulation concrete prism test) to obtain ASR induced expansion with and without external supply of alkali. The dissolution rates of the granodiorite used in the concrete mix and the gel formation rates are determined under concrete-like conditions (pH 13.8, with/without Ca(OH)2 and NaCl) at different temperatures. A micromechanics based computational model with aggregate-scale diffusion and reaction kinetics coupled to an Eigenstrain based micromechanics damage model is developed for the simulation of ASR induced expansion and damage. Data from the experimental program are used to calibrate and validate the computational model. Model predictions show that for the given concrete mixture, ASR induced expansion in the specimen exposed to water is predominantly governed by microcracking in the aggregate, while the expansion in the specimen subjected to external alkali supply is governed by microcracking in both the aggregates and the cement paste.



中文翻译:

ASR 引起的混凝土劣化:实验和多尺度建模

使用实验室实验和计算模型研究了 ASR(碱-二氧化硅反应)引起的路面混凝土试样膨胀和损坏的过程。在实验程序中,混凝土试件进行 CS-CPT(气候模拟混凝土棱柱试验)以获得有和没有外部碱供应的 ASR 诱导膨胀。混凝土混合物中使用的花岗闪长岩的溶解速率和凝胶形成速率是在类似混凝土的条件下确定的(pH 13.8,有/没有 Ca(OH) 2和 NaCl) 在不同温度下。开发了一种基于微观力学的计算模型,该模型具有与基于特征应变的微观力学损伤模型耦合的聚集体尺度扩散和反应动力学,用于模拟 ASR 引起的膨胀和损伤。来自实验程序的数据用于校准和验证计算模型。模型预测表明,对于给定的混凝土混合物,暴露于水的试样中 ASR 引起的膨胀主要受集料中的微裂纹控制,而受到外部碱供应的试样的膨胀受集料和水泥中的微裂纹控制粘贴。

更新日期:2021-08-24
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