混凝土碳化深度模型及其影响因素研究

发布时间：2018-04-23 02:21

本文选题：混凝土 + 碳化　；参考：《辽宁工程技术大学》2015年硕士论文

【摘要】：混凝土结构的耐久性问题日益凸显,越来越受到重视。混凝土碳化是耐久性研究的一个重要分支,由碳化引起的结构破坏损害不可估量。混凝土碳化指空气中的二氧化碳等酸性气体与混凝土内的可碳化物质发生反应,致使混凝土内的结构组成发生改变的现象。混凝土碳化会影响混凝土保护层的功能,给结构带来严重的安全隐患。因此,混凝土碳化问题始终是重点研究课题。本论文依据《普通混凝土长期性能和耐久性能试验方法标准》(GB/T 50082—2009)进行混凝土快速碳化试验,对混凝土碳化的主要影响因素—水泥用量、水灰比、粉煤灰掺量、环境温度、相对湿度展开研究,对上述影响因素与混凝土碳化的关系进行探讨。结果表明：对于混凝土自身影响因素,水灰比和粉煤灰掺量越大,混凝土越容易碳化,相反地,增加水泥用量会抑制混凝土碳化。研究水灰比和水泥用量的综合影响可知,占主导地位的是水灰比。对于环境影响因素,在本文研究范围内,温度越高,加快混凝土碳化,相对湿度越大,混凝土不易碳化。本文在前人研究的基础上,以混凝土快速碳化试验的试验结果计算出上述因素对混凝土碳化的影响系数,建立考虑水泥用量、水灰比、粉煤灰掺量、环境温度、相对湿度的混凝土碳化深度预测模型。通过参数转换,用大型通用有限元分析软件ANSYS热分析模块建立模型,提出合理的假设条件,对混凝土碳化过程进行数值模拟,用模拟结果和实例对混凝土碳化深度预测模型进行验证。仅由单一因素建立的模型具有局限性,而且现有预测模型对环境影响因素的研究较少。本文建立的碳化模型考虑环境因素的影响,更具实用性。
[Abstract]:The durability of concrete structure is becoming more and more important. Carbonation of concrete is an important branch of durability research, and the damage caused by carbonation is incalculable. Carbonation of concrete refers to the reaction of carbon dioxide and other acidic gases in the air with carbonable substances in concrete, which results in the change of structure composition in concrete. The carbonation of concrete will affect the function of concrete cover and bring serious hidden danger to the structure. Therefore, the carbonation of concrete has always been a key research topic. In this paper, the rapid carbonation test of concrete is carried out according to the standard of test methods for long-term performance and durability of ordinary concrete (GB / T 50082-2009). The main factors affecting the carbonation of concrete are cement dosage, water-cement ratio, fly ash content, ambient temperature, etc. The relationship between the above factors and concrete carbonation is discussed. The results show that the more the ratio of water to cement and the content of fly ash is, the easier carbonation of concrete is. On the contrary, the increase of cement content will inhibit the carbonation of concrete. The comprehensive influence of water cement ratio and cement content shows that water cement ratio dominates. For the environmental factors, the higher the temperature is, the faster the carbonization of concrete is, and the greater the relative humidity is, the harder the carbonation of concrete is. On the basis of previous research, the influence coefficient of the above factors on concrete carbonization is calculated based on the experimental results of concrete rapid carbonization test, and the factors such as cement content, water cement ratio, fly ash content, environment temperature are established. The prediction model of concrete carbonation depth based on relative humidity. Through parameter conversion, the model is established by using the large scale finite element analysis software ANSYS thermal analysis module, and the reasonable assumption condition is put forward, and the carbonation process of concrete is simulated numerically. The prediction model of concrete carbonation depth is verified by simulation results and examples. The model established by single factor is limited, and the existing prediction model has little research on environmental impact factors. The carbonation model established in this paper takes into account the influence of environmental factors and is more practical.
【学位授予单位】：辽宁工程技术大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TU528

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