| 摘要: |
| 针对海洋环境条件，重点研究了粉煤灰混凝土的抗冻性和氯离子渗透性能的相互关系。试验分别研究了水胶比、粉煤灰等量取代水泥掺量大小、引气剂掺量等因素对抗冻性和抗氯离子渗透性能的影响，并与普通混凝土进行了对比。结果表明,粉煤灰不增加混凝土的抗海水冻融耐久性；粉煤灰增加混凝土的抗氯离子渗透性能，但是掺量超过30%，抗氯离子渗透性能下降；粉煤灰对混凝土抗冻性和抗氯离子渗透性的耦合影响在30%左右存在一个最佳掺量。为评估混凝土的抗冻性和氯离子扩散性的耦合性能，提出了新的评价方法——冻渗比(R值方法)，并进行了试验验证。SEM和MIP微观分析与R值方法评价的结果是吻合的。
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| 关键词: 粉煤灰 海工混凝土 抗冻性 氯离子渗透 评价方法 |
| DOI： |
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| 基金项目:国家自然科学基金项目(50702080) |
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| Characteristics of frost resistance and resistance to chloride-ion penetration of fly ash concrete in a marine environment |
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YANG Wen-wu,HUANG Yu-bin,GUO Li-jie
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| Abstract: |
| The properties of fly ash (FA) concrete used at a marine environment were studied, especially the correlation between freeze-thaw durability and chloride-ion penetration properties. The factors such as water-cement ratio, FA alternative cement content equivalent, and air-entraining agent were experimentally studied and compared with the ordinary concrete (OPC). The results show that adding FA did not increase freeze-thaw durability of concrete; but increases its chloride ion impermeability when the content was less than 30% by mass, which is the best one of coupling properties of both frost-resistance and impermeability. While decreasing its impermeability more than 30%. the both properties were improved only in combination with FA and air entraining agent in concrete at sea water conditions. Furthermore, a new assessment method (R-value method) was brought forward to evaluate the performance of both freeze-thaw durability and chloride ions diffusion of various concretes in a marine environment and verified by an experimental study. SEM micrographs and MIP analyses coincided considerably with R-value method’s conclusions.
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| Key words: fly ash marine concrete freeze-thaw durability chloride-ion penetration assessment method |
