【作者】 彭波；

【导师】 胡曙光； 丁庆军；

【作者基本信息】 武汉理工大学 ， 材料学， 2002， 硕士

【摘要】 随着建筑物对混凝土性能的要求越来越高，高强混凝土已成为近代混凝土技术发展的主要方向。但是，其存在自收缩开裂、湿涨开裂以及脆性等缺点大大影响了高强混凝土的工作及使用性能。因此，提高高强混凝土的抗裂功能，意义十分重大。 本文研究了在低水胶比、大掺量高效减水剂、掺有一种或多种掺合料条件下，高强混凝土不同龄期水化产物的组成、结构与性能以及高强混凝土中水泥石与粗集料之间的界面过渡区的组成与结构。研究了不同水胶比、复合缓凝成分高效减水剂及矿物掺合料的掺加方式、掺量对高强混凝土水泥浆体水化放热过程和水泥浆体的水化热、水化放热速率以及最高温升的影响规律。探明了高强混凝土中水泥浆体的水化硬化过程、矿物掺合料之间的相互作用机理。研究结果表明，采取大掺量高效减水剂、低水胶比和掺加矿物掺合料的技术措施能够改善界面过渡区微观结构。 在此基础上，研究了高强混凝土在不同龄期的收缩规律，发现高强混凝土的收缩特性与普通混凝土存在显著不同。其早期收缩主要是塑性收缩，而后是冷缩和自收缩，长期收缩以干燥收缩为主。针对高强混凝土的收缩特性以及性能特点，本文提出将膨胀剂引入高强混凝土内进行补偿收缩，研究了粉煤灰、矿渣、硅灰等掺和料对混凝土工作、力学耐久性能的影响和C50～C80高强微膨胀补偿收缩混凝土的力学与工作性能，配制出具有很好的可泵性能和耐久性能的混凝土。 通过大量工程的调查分析，提出并讨论高强混凝土应按照工程类别进行抗裂性能进行设计以及混凝土工程应该从多方面采取综合性措施进行裂缝控制的观点。认为只有从工程设计、混凝土配合比优化、生产、运输、浇筑以及养护等施工环节都加强质量管理与控制，才能有效抑制裂缝的产生。 针对剪力墙等重要工程结构易开裂问题，配制了纤维增强微膨胀混凝土，并对其工作性能、体积稳定性以及力学性能进行了研究。研究成果应用 武汉理工大学硕士学位论文于工程实践，解决了超长剪力墙易开裂问题，取得了显著的经济效益。更多还原

【Abstract】 With many good properties, high strength concrete (HSC) is becoming the developing direction of modern concrete technology and extensively applied in many fields. But the questions of buildings cracking of HSC are very serious. It brings people a lot of trouble and unnecessary loss. So, to buildings, it is very important to enhance the quality of HSC anti-cracking property. Aiming at the main problems of HSC, we put forward that using expansive agent and fiber in HSC to compensate and limit the shrinkage. These measures can conquer the defects of HSC and make HSC possess excellent performances, such as the good workability and high flow ability.Based on above, the characteristics of hydration hardening process and microstructure of HSC as well as the interfacial layer between cement paste and coarse aggregate are investigated under low water cement ratio, high content superplasticiser and with one kind or more than one kind of mineral materials condition, the reaction mechanisms of different mineral materials are also discussed. The influence of mineral materials such as fly ash, blast furnace slag and silica fume on expansion performance of the common concrete and compensating-shrinkage concrete was researched. To the common concrete, adding fly ash or blast furnace slag can decrease the shrinkage rate, but adding silica fume deteriorate the shrinkage rate. To compensating-shrinkage concrete, mineral materials added cause its expansion rate decrease. Furthermore, the reasons of crack generating from the point of material and structure are analysis. The shrinkage characteristics of HSC and normal concrete at short term and long term are researched. Based on the above research, high performance expansive C50-C80 concrete, which posses good expansive properties, excellent flow ability, low slump loss and hydration heat.In order to improve the anti-cracking of some important projects, such as Cutting Wall, the workability and bulk stability of fiber-reinforced micro expensive concrete are researched. At last, this kind of material with high anti-cracking property is applied to actual project and the effect is exciting. We find that crackingcontrol is a synthetically project. The project design condition, produce, transport, pouring and curing, all of them are very important to the project quality. Because construction and curing quality is more important to anti-cracking performance of HSC and fatal to the compensating-shrinkage concrete than anything else, we should pay attention to them. So we think that anti-cracking of HSC should be designed according to project sorts. At last, we apply our achievement to actual project and get good effects.更多还原