A numerical and experimental study of aggregate-induced shrinkage cracking in cementitious composites
A numerical and experimental study of aggregate-induced shrinkage cracking in cementitious composites
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DOI：
10.1016/j.cemconres.2011.09.013
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发表时间：
2012-02-01
影响因子：
11.4
通讯作者：
Lura, Pietro
中科院分区：
文献类型：
--
作者：
Idiart, Andres;Bisschop, Jan;Lura, Pietro
水泥基复合材料中的骨料在干燥过程中会对基体收缩产生机械约束，在一定条件下会导致内部微裂纹的产生。在目前的工作中，这种现象是使用一个二维（2D）的数值模型和近似2D的实验方法进行研究。实验和模拟样本的简化和匹配的空间聚集体分布，使实验和模型预测之间的定量比较。特别是，骨料的尺寸和体积分数的内部微裂纹的程度的影响进行了评估。进行定量比较的主要挑战突出和讨论。这些问题涉及：（i）设计没有湿度梯度效应的实验的困难;（ii）实验裂纹检测极限;和（iii）模型中基质相的蠕变响应的作用。结果表明，存在一个临界骨料的大小，低于该骨料约束不会引起可检测的微裂纹。(C)2011爱思唯尔有限公司保留所有权利。
Aggregates in cementitious composites subject to drying lead to mechanical restraint of the matrix shrinkage, which under certain conditions may lead to internal microcracking. In the present work this phenomenon is investigated using a two-dimensional (2D) numerical model and an approximate 2D experimental approach. Experimental and simulated samples with simplified and matching spatial aggregate distributions were produced to make a quantitative comparison between experiments and model predictions. In particular, the effects of aggregate size and volume fraction on the degree of internal microcracking are assessed. The main challenges of performing a quantitative comparison are highlighted and discussed. These are related to: (i) the difficulty of designing experiments without moisture gradient effects; (ii) the experimental crack detection limit; and (iii) the role of the creep response of the matrix phase in the model. The results suggest the existence of a critical aggregate size below which aggregate-restraint does not cause detectable microcracking. (C) 2011 Elsevier Ltd. All rights reserved.