【作者】 刘晓东；

【导师】 李固华；

【作者基本信息】 西南交通大学 ， 结构工程， 2008， 硕士

【摘要】 高性能混凝土是对传统混凝土的重大突破是一种环保型、集约型的新型材料,在节能节料、工程经济、劳动保护以及环保等方面都具有重要意义,它的出现是混凝土发展史上的一个新的里程碑。21世纪,是高性能混凝土的时代。氯离子渗透性能是评定高性能混凝土耐久性的重要指标,也是评定钢筋混凝土结构中钢筋耐锈蚀的重要指标,本文结合国内外矿物掺和料混凝土的发展及成果研究,提出了采用粉煤灰、磨细矿渣以达到提高混凝土耐久性的要求。本课题利用0.36和0.5两种水胶比,通过设计使用不同掺量的粉煤灰、磨细矿渣和双掺粉煤灰和磨细矿渣等量置换水泥的配比方案,再加以硅灰和高效减水剂,目的是提高高性能混凝土的抗氯离子渗透性能。以期望配制出性能优良的高性能混凝土,并对各组混凝土进行了基本力学性能和混凝土氯离子扩散系数两个方面的试验研究。混凝土氯离子扩散系数试验采用混凝土氯离子扩散系数快速检测的NEL法。研究发现,在掺入粉煤灰、磨细矿渣以及双掺两种矿物外加剂后,混凝土具有良好的工作性能和力学性能。对比组混凝土的28天龄期强度值同基准组接近,加入磨细矿渣还略有提高。在抗渗性方面,加入矿物外加剂的混凝土氯离子扩散系数明显优于基准组,能将混凝土抗渗等级提高一到两个等级。而且随着掺量的不同,提高的幅度也有差异。本文根据数据利用数值方法建立了矿物外加剂掺量-氯离子扩散系数方程,提出对于渗透性的矿物外加剂最优掺量。然后通过微观分析,分析了掺入矿物外加剂后混凝土水化产物和孔结构的变化,从物理和化学两个方面阐述了产生该实验结果的原因。本文通过以上的分析,在利用粉煤灰和磨细矿渣在配制高性能混凝土中,提出了相关的建议。并结合实际施工情况,提出了改善混凝土抗渗性的措施。更多还原

【Abstract】 High Performance Concrete （HPC） is a kind of environmental and intensivism material, which is a breakthrough to the traditional concrete. It has significances in saving source and material, engineering Economics, labor force protection, and environment protection etc. It is a new milestone for the development of the concrete history. The 21^st century is the epoch of the HPC.Permeability of chloride ion is an important index to assess both the high durability of concrete, and the corrosion resistance of the steel bar in the structure of the reinforced concrete. Combining with the development and the research fruit of the concrete from home and abroad, this article puts forward to use fly ash and slag powder to improve the durability of concrete. In order to confect the concrete with excellent capability, the course contrasts two kinds of Water-cement ratios, 0.36 and 0.5; permutes cement with the same amount substitution from using different parameter of fly ash, slag powder, concrete mixed with fly ash and slag powder, then add fly ash and high-capability water-reduce dose. the aim is to improve the permeability resistance of chloride ion of the high performance concrete. Moreover, it makes trials for the concrete in the basic mechanical capability and diffusion modulus of chloride ion. It adopts NEL for the trial of the diffusion modulus of chloride ion.From the research, it is found that the concrete will be have excellent working and mechanical capability after being mixed with the coal ash, the slag powder and the admixture of fly ash and slag powder. The 28-day age intensity of the concrete is the quite the same as the benchmark, and it will be better after put into slag powder. In the aspect of permeability resistance, diffusion modulus of chloride ion mixed with admixture is more excellent than the benchmark. It can improve one or two levels for the permeability resistance of the concrete. The level will be different as per the parameter.The article has set up the equation of the mineral admixture and the parameter of the diffusion of the chloride ion according to the numerical analysis of the experiment data. Through microcosmic analysis, it analyses the change of the hydration products and the pore-structure after the concrete intermingled with mineral admixture and expounds the reason of the trial result from physics and chemistry.After above analysis, it gives the suggestion on utilizing the fly ash the slag powder in confecting the excellent capability of the concrete and gives the measures to improve the permeability resistance of the concrete.更多还原