应力和氯盐环境下海工混凝土的碳化性能

Carbonation Performance of Marine Concrete under Stress and Chloride Environment

浏览量:

关键词:

应力;氯盐环境;海工混凝土;碳化

Key words:

Stress; Chloride environment; Marine concrete; Carbonation

刊期:

2018 No.5

DOI:

文章编号:

1000-4637(2018)05-01-05

基金项目:

国家重点研发计划资助(2016YFC0401610);中央级公益性科研院所基本科研业务费专项资金(Y416018)。

作者:

钱文勋1,2,3,陈迅捷1,2,3,蔡跃波1,2,3,庄华夏1,2,3

单位:

1.南京水利科学研究院,210029;2.水利部水工新材料工程技术研究中心,南京 210029; 3.水文水资源与水利工程科学国家重点实验室,南京 210029

摘要

摘   要:配制两种水胶比的海工高性能混凝土试件,开展了氯盐-碳化干湿循环试验以及拉应力-氯盐-碳化干湿循环试验,通过测试分析混凝土抗压强度和碳化深度,研究了应力和氯盐环境下海工混凝土的碳化性能。试验结果表明:氯盐-碳化干湿循环条件下,混凝土抗压强度呈现先增大后降低的现象,长期的碳化作用会引起抗压强度的降低;存在一个与抗压强度有关的临界碳化深度,碳化作用在达到临界碳化深度之前可以提高抗压强度,达到临界碳化深度之后则会降低抗压强度。在拉应力-氯盐-碳化干湿循环条件下,拉应力和氯离子侵蚀均会增大混凝土的碳化速度,两者同时作用时,对碳化速度的增大作用会相互叠加。

Abstract: Two groups marine engineering high-performance concrete samples with different W/B ratio were prepared. Two dry-wet cycling tests about the interactive environment with chloride ion and carbonation and the multiple environment with tensile stress, chloride ion and carbonation were designed. The compression strength and the carbonation depth were analyzed to research the carbonation performance of marine concrete under the chloride environment and stress. The results show that the compression strength is increased at early period and then decreased gradually under the dry-wet cycling condition about chloride and carbonation; a critical carbonation depth related to the compression strength is existed, carbonation can improve the compression strength before the critical carbonation depth and reduce the compression strength after the critical carbonation depth. Under the dry-wet cycling condition about tensile stress, chloride and carbonation, both tensile stress and chloride ion can increase the carbonation speed, these promotion can overlay each other.

结论

(1)在氯盐-碳化干湿循环条件下,混凝土抗压强度呈现先增大后降低的现象,碳化作用并不能持续地增加混凝土抗压强度,长期的碳化作用反而会引起抗压强度的降低。
(2)在拉应力-氯盐-碳化干湿循环条件下,拉应力和氯离子均会增大混凝土的碳化速度,两者同时作用时,对碳化速度的增大作用会相互叠加。相对于高水胶比混凝土,拉应力作用和氯离子侵蚀对低水胶比混凝土碳化性能的影响更加显著。
(3)在氯盐-碳化干湿循环条件下,碳化作用存在一个与抗压强度有关的临界碳化深度。碳化作用在达到临界碳化深度之前可以提高抗压强度,达到临界碳化深度之后作用则会降低抗压强度。

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引用本文

钱文勋,陈迅捷,蔡跃波,等.应力和氯盐环境下海工混凝土的碳化性能[J].混凝土与水泥制品,2018(5):1-5.

QIAN W X,CHEN X J,CAI Y B,et al.Carbonation Performance of Marine Concrete under Stress and Chloride Environment[J].China Concrete and Cement Products,2018(5):1-5.


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