Influence of the aggregate on the electrical conductivity of Portland cement concretes
Influence of the aggregate on the electrical conductivity of Portland cement concretes
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DOI：
10.1016/s0008-8846(03)00166-2
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发表时间：
2003-11-01
影响因子：
11.4
通讯作者：
Levita, G
中科院分区：
文献类型：
--
作者：
Princigallo, A;van Breugel, K;Levita, G
几个高性能的波特兰混凝土的导电性和抗压强度与不同数量的碎骨料和砂已被测量在早期的等温条件下（20 degreesC）。总骨料体积分数从0（普通膏）到0.75不等，并使用破碎骨料和砂之间的恒定重量比（1.2）。w/c比为0.37，并且使用微粉二氧化硅（浆料形式）和水溶液中的超增塑剂。在电导率开始下降之前所花费的时间与诱导期非常好地相关。电导率的下降被骨料稍微延迟。通过不同的数值和分析模型[硬核软壳模型（HCSS），微分有效介质理论（DEMT），Lu-Torquato，麦克斯韦]的电气数据的分析，允许的界面过渡区（ITZ）的属性的估计。特别是，约9微米的ITZ厚度和ITZ体电导率比类似于2.5被发现。存在一个通过界面区域的电测量和建模时，发现骨料体积分数超过60%的膨胀路径。最后，导出了导电率、抗压强度和骨料量之间的新关系。(C)2003 Elsevier Ltd.保留所有权利。
The electrical conductivity and compressive strength of several high-performance Portland concretes with different amounts of crushed aggregate and sand have been measured at early age in isothermal conditions (20 degreesC). The total aggregate volume fraction varied from 0 (plain paste) to 0.75 and a constant weight ratio (1.2) between crushed aggregate and sand was used. The w/c ratio was 0.37 and microsilica (in slurry form) and a superplasticizer in water solution were used. The time taken before the electrical conductivity began to drop correlated very well with the induction period. The drop of conductivity was slightly delayed by the aggregate. The analysis of the electrical data, by means of different numerical and analytical models [hard core soft shell model (HCSS), differential effective medium theory (DEMT), Lu-Torquato, Maxwell], allowed an estimate of the properties of the interfacial transition zone (ITZ). In particular, an ITZ thickness of about 9 mum and an ITZ to bulk conductivity ratio of similar to 2.5 were found. The existence of a percolating pathway through the interfacial regions was found by both electrical measurement and modeling when the aggregate volume fractions exceeded 60%. Finally, a new relationship among electrical conductivity, compressive strength, and aggregate amount was derived. (C) 2003 Elsevier Ltd. All rights reserved.