【作者】 陈寒斌；

【导师】 陈剑雄；

【作者基本信息】 重庆大学 ， 材料学， 2006， 博士

【摘要】 酸沉降、酸雨是人类活动引起的严重环境污染。对生态环境和建筑带来极大危害,也加速混凝土结构的腐蚀,已列为世界严重公害前三位。我国酸雨地区达30%,酸雨pH值在5.6以下。而快速发展的水泥行业给环境带来严重的破坏。有效利用工业废渣、减小环境污染,配制严酷环境下高耐久混凝土是可持续循环经济的一个重要环节,也是建设节约型经济社会与可持续发展的必要保证。本文针对上述问题,结合国家西部十大重点工程之一的重庆轻轨主体结构混凝土百年耐久性研究项目,对严重酸雨环境下的混凝土进行了研究,并对混凝土的环境性进行了评价,得出的研究结论和成果如下:(1)高性能混凝土的可持续发展,应在其定义中增加环境协调性的新内容及评价方法,即对其使用的组分结合环境进行选择,要求生产过程、最终产品和再循环应用都应与环境相协调,加入新组分,进行环境修复,以实现与生态环境的良性循环与协调。并对发展高性能混凝土环境协调性的途径进行了分类。(2)重庆是世界酸雨污染代表地区之一,重庆空气污染特点主要表现为高浓度的二氧化硫污染,降水的pH最小值为2.85,降水的年平均值为4.14～4.76,酸雨pH平均值为4.14～4.55,酸雨频率范围为93.7%～34.7%。常年降雨水的pH值属于对混凝土强侵蚀及特强侵蚀作用范围。对象重庆轻轨这样的重要结构工程就必须进行酸雨对其耐久性的影响研究。(3)本文运用生命周期评价方法(LCA)进行了对掺加钛渣、锂渣与煅烧磨细煤矸石混掺以及掺复合TG粉的新型混凝土研究,并与同强度等级的混凝土的环境性进行了评价,由于这几种渣体的填充效应与增强效应,在相同强度等级时,水泥用量大幅度降低,未资源化的渣体大量使用,从而有效地改善了混凝土的环境性能。提高了混凝土的耐久性,延长了混凝土的使用年限,实现了混凝土与环境的协调。(4)结合严重酸雨地区的实际情况,采用周期浸泡和喷淋方法对混凝土进行耐酸性实验,根据混凝土的强度损失、重量损失与中性化深度,定性地评价混凝土的耐酸性。(5)由于钛渣、锂渣、TG复合渣矿物掺合料的火山灰效应、填充效应、强度效应与超叠加效应,掺加有钛渣、锂渣及TG粉的水泥,水化产物的火山灰反应,形成具有网络结构致密的C-S-H凝胶,改善了水泥石的孔结构,使水泥浆与集料界面变得密实。水泥石的总孔隙(孔径37.5 ? -75000 ?)与有害孔明显减少,毛细孔半径变小,凝胶孔增加。随着水化硬化时间的延长,水泥石的孔隙率、孔径分布及其物理状态也相应改善。(6)碱钛渣-矿渣混凝土90天强度达到88MPa,120天强度超过90MPa。用更多还原

【Abstract】 Acid precipitation and acid rain are severe environmental pollution caused by human activities, which bring great damage to the ecological environment and buildings and accelerate corrosion of the concrete structures, they are considered as one of the first three severe public hazards in the world. In China, the regions with acid rain occupy up to 30 % and the pH value of the acid rain is less than 5.6. Rapid developed cement industry caused a great damage to the environment. Effective utilization of industrial solid wastes to reduce environmental pollution and preparation of high durable concrete under severe condition is an important link in sustainable recirculation economy and a necessary guarantee for establishing a society with resource saving and sustainable development.In this paper, aiming at above-mentioned problems in combination with the research project on centennial durability of concrete for the main structure of Chongqing Light Rail, which is one of the ten key construction projects in West China, the concrete working in the environment with severe acid rain has been studied and the environmental effect of the concrete has been evaluated, the conclusions and results of the study are as follows:(1) For sustainable development of high performance concrete, in its definition, a new content, namely, the environmental coordination and evaluation method should be added, that is, the component used should be chosen with considering its relation with the environment and the manufacture process, final product and its recirculation all should be in coordination with the environment, the environment will be restored by adding new component to realize the positive circulation and coordination with ecological environment. The ways for developing environmental coordination of high performance concrete are classified.(2) Chongqing is one of the typical regions with acid rain pollution in the world, the character of air pollution in Chongqing is expressed in pollution of high concentrated sulfur dioxide, the minimum pH value of precipitation is 2.85 and the annual average of precipitation is 4.14 ~ 4.76, the mean pH value of acid rain is 4.14 ~ 4.55, the frequency of acid rain ranges 93.7%～34.7%. The pH value of precipitation is in the range of strong corrosion and extra strong corrosion to the concrete. In respect to the key construction project such as the Chongqing Light Rail, it is necessary to study更多还原