混凝土的化腐蚀过程,在可变温度干湿循环下具有不同的水结合比率
Lei Wang1, Chunhong Chen1,2, Ronggui Liu2
1School of Urban Construction, Changzhou University, Changzhou 213164, China.
Materials (Basel, Switzerland)
|May 25, 2024
概括
这项研究表明,较高的水结合比率 (w/b) 和可变温度的干湿周期显著降低了混凝土的质量.
科学领域:
- 土木工程 土木工程是指土木工程.
- 材料科学 材料科学 材料科学
- 材料的耐用性 材料的耐用性
背景情况:
- 混凝土结构面临着温度波动和化物进入等环境因素的退化.
- 了解干湿周期和可变温度对混凝土性能的综合影响,对于基础设施的寿命至关重要.
研究的目的:
- 调查不同水结合比 (w/b) 在循环干湿条件下对混凝土的机械性能和化物耐受性的影响.
- 为了评估与恒定温度相比,可变测试温度对混凝土恶化的影响.
- 分析影响混凝土性能的微观结构变化和损坏机制.
主要方法:
- 具有四个w/b比率 (0.29,0.33,0.39,0.46) 的混凝土样本经过了干湿循环.
- 在可变和恒定温度条件下进行测试,以模拟服务环境.
- 测量了机械性能 (压力强度,分裂抗拉强度),质量损失,相对动态弹性模量,孔隙性,化物扩散深度和化物含量.
主要成果:
- 机械性能最初增加,然后随着干湿周期下降;化物耐受性持续下降.
- 较高的w/b比率加剧了性能恶化,增加了多孔性和化物入.
- 可变的温度周期比恒定温度造成的累积损伤更大,加快了化物扩散和结合.
结论:
- 更高的w/b比率和可变温度周期加快了混凝土的降解,降低了机械性能和化物耐腐蚀性.
- 满足机械和耐腐蚀性要求的最佳w/b比值在0.29和0.39之间.
- 可变温度的干湿循环比恒温循环对混凝土的耐用性构成更大的风险.
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