【作者】 李宇；

【导师】 何忠茂； 乔宏霞；

【作者基本信息】 兰州理工大学 ， 结构工程， 2014， 硕士

【摘要】 西部盐渍土地区混凝土受到干湿循环、冻融循环以及盐卤侵蚀等多重因素影响,其耐久性问题特别严重。中卫地区也不例外,该区域具有光照充足,太阳辐射较强,温差较大,气候干燥等特点,处在中卫盐渍土地区的建筑物,不仅受到冷热交替、干湿循环或者冻融交替的恶劣环境因素的影响,而且该地区的有害盐对混凝土的侵蚀也较大。所以研究当地混凝土的耐久性问题,并将之推广到中卫地区以及西部地区显得尤为重要。在混凝土耐久性寿命预测方面,国内外研究者基于氯盐腐蚀、碳化腐蚀、混凝土原材料影响等方面做了大量的工作,研究成果较集中,但是基于硫酸盐侵蚀的耐久性寿命预测成果很少,而针对中卫地区硫酸盐侵蚀的情况进行的研究很少,更未见到中卫典型盐渍土地区基于硫酸盐腐蚀的混凝土材料耐久性寿命预测的研究。本文通过室内试验和现场埋设试验对比,进行的中卫典型盐渍土地区基于硫酸盐腐蚀的混凝土材料耐久性寿命预测的试验,分析中卫地区室外暴露的混凝土数据,并结合室内试验数据,寻求能够相对较客观的评价中卫地区的混凝土的评价参数,进而对中卫地区的混凝土的寿命进行预测。本文的主要研究内容如下：1、试验方案的设计：针对中卫地区的实际情况,模拟混凝土在干湿循环,冻融循环和硫酸盐侵蚀等条件下的腐蚀,设计室内加速试验方案。2、耐久性评价参数的选取：选取试件的相对动弹性模量评价参数和相对质量评价参数,比较各评价参数优劣,结合中卫地区的实际情况,得出一个更符合实际的评价参数。3、影响因素的选取：为了得到更好更全面的耐久预测模型,试验主要分成四组,一组主要考虑冻融循环单因素作用下的混凝土耐久性；一组主要考虑硫酸盐和干湿循环耦合作用下的混凝土耐久性；第三组则为室外暴露试验,把试件埋在室外的相应地点进行耐久性研究,第四组为室内标准养护室对比试验组。4、耐久性寿命预测：根据目前国内外对混凝土耐久性及其寿命预测的研究方法,结合本实验的特殊性,设计耐久性评价参数,确定混凝土寿命预测的参数及其方法,比较本文三种不同实验条件下的混凝土耐久性损伤程度,为以后中卫地区及其西北地区的混凝土的耐久性寿命预测提供一点参考。更多还原

【Abstract】 The concrete of salty soil region in northwestern areas is suffering from drying-wetting cycle, freezing-thawing cycle and bittern erosion, so the durability of this concrete is confront with growing damage. ZhongWei region is no exception, the region has the sufficient sunshine, strong solar radiation, temperature difference is bigger, dry climate, etc. The buildings in salty soil region in ZhongWei area are not only influenced by alternating hot and cold, dry and wet cycle or alternate freezing and thawing environment factors, but also suffer from the harmful salts. So study the problem of the durability of the concrete and promotion to the ZhongWei region and northwestern region seems particularly important.In terms of concrete durability life prediction, the researchers at home and abroad based on chlorine salt corrosion, carbonation corrosion, concrete raw materials affect aspects have done a lot of work, research results are relatively concentrated, but very few durability life prediction results based on sulfate attack.However, research about sulfate salty soil in ZhongWei is very few, let alone ZhongWei typical salty soil region based on the sulfate corrosion of concrete durability life prediction research. In this article, by contrast the indoor experiment and the embedding test, the experiment of ZhongWei salty soil region based on the sulfate corrosion of concrete durability life prediction is carried out. Analysis of outdoor exposure test data in ZhongWei and look to relatively objective evaluation parameters for the assessment of concrete in ZhongWei are on the way, addition to make predictions about the life of the concrete in ZhongWei.This article main research content is as follows:The first, design test plan:in view of the actual situation in ZhongWei, we will simulate the concrete in the dry-wet circulation, the freeze-thaw cycle conditions of corrosion and design indoor accelerated test plan.The second,selection the parameters of the durability evaluation:in addition to using the relative quality loss evaluation parameters and the relative dynamic elastic modulus evaluation parameters to reflect the durability, comparing various evaluation parameters and looking for more realistic evaluation parameters.The third, selection of influencing factors:in order to get better and more comprehensive durability prediction model, mainly divided into three groups, a set of single factor under the action of freezing-thawing cycle of concrete durability, a set of main consideration under the coupled action of sulfate and the dry-wet cycle concrete durability, the third group is outdoor exposure test, which buried the block in the corresponding outdoor location for durability research.The last, thedurability life prediction:according to the current domestic and international research on concrete durability and the life prediction method, designing the durability evaluation parameters and determining the parameters and the method to estimate service life of concrete. Compared in this paper, there are three kinds of damage degree of the durability of the concrete under different experimental conditions, in order to provide a little reference for Concrete durability life prediction in ZhongWei and the northwestern region.更多还原