水硬性石灰的设计制备与性能研究

发布时间：2018-05-02 16:12

本文选题：古城墙 + 石灰　；参考：《东南大学》2015年硕士论文

【摘要】：建筑遗产的保护和适应性利用是我国城市发展的重要课题。我国古城墙历史悠久且数量众多,但由于自然灾害及人为破坏,许多古城墙已经濒临毁灭,迫切需要人们合理的修复加固。在对破损的古城墙进行修复加固时,当前一般简单地采用现代水泥材料进行处理,但实践表明,现代水泥基材料与古代以木材、砖石为主要的建筑材料在物理化学上适应性不良。中国古城墙使用的胶凝材料主要是石灰,当前欧美国家几乎所有的砖石古迹均采用石灰材料为基料的修复材料。基于这种现状,水硬性石灰作为一种文物建筑保护的新型材料日益受到重视。本研究根据欧洲标准EN-459,采用各原材料复配的方式制备得到水硬性石灰。首先系统研究了石灰-白水泥-重钙微粉-活性微粉复合胶凝材料质量比、水灰比对胶凝体系物理力学性能的影响规律,包括吸水率、软化系数和抗压、抗折强度,以及干燥收缩性能等,确定最佳基准配比L1：石灰：白水泥：重钙微粉：活性微粉=27：36：27：10,试验砂浆胶砂流动度为185mm,28d抗压强度达到7.3IMPa,软化系数达到0.66。并以此为基础,研究了不同掺量的铝制添加剂、聚丙烯纤维及石绒三种添加剂对水硬性石灰基准配比L1物理力学性能、早期干燥收缩(28d)的影响规律,试验结果表明：1%铝制添加剂的掺入使砂浆强度较基准配比砂浆提高了19.4%,早期干燥收缩降低33%；聚丙烯纤维掺入对砂浆早期干燥收缩影响不大,1‰、2%0、3960掺量砂浆的强度分别提高了20%、21.9%、25.3‰而石绒的加入使28d干燥收缩增加16%～32%,抗压强度较基准配比呈先降低后提高趋势。其次,通过加速碳化试验对水硬性石灰的碳化过程进行了研究；本文还分别对水硬性石灰材料的剪切粘结强度和拉伸粘结强度进行研究。其中,基准配比试样的剪切粘结强度为0.186MPa,高于传统水泥砂浆和石灰砂浆的0.069MPa、0.022MPa,拉伸粘结强度为0.114MPa,试验满足古城墙修复砂浆的“可逆性”要求。另外,本文基于混凝土耐久性试验方法,研究了水硬性石灰砂浆在冻融环境、硫酸盐全浸泡及硫酸盐-干湿循环耦合作用下的耐久性能。结果表明,相比于传统石灰砂浆(碳化后),水硬性石灰的耐久性能更好,其中,聚丙烯纤维的掺入显著调高了抗冻性能{铝制添加剂的掺入则提高了抗硫酸盐侵蚀性能,但抗冻性不佳。最后,本文利用扫描电镜(SEM)、XRD、MIP技术测试了水硬性石灰的微观结构与组织形貌、水化产物及砂浆的孔结构；并利用水化热方法分析了水硬性石灰早期水化进程及微结构形成过程。
[Abstract]:The protection and adaptive utilization of architectural heritage is an important subject of urban development in China. The ancient city walls of our country have a long history and a large number, but due to natural disasters and man-made destruction, many ancient walls have been on the verge of destruction, so it is urgent for people to repair and strengthen them reasonably. In the course of repairing and strengthening the damaged ancient walls, the modern cement materials are generally used to deal with them, but the practice shows that the modern cement base materials and the ancient wood, Masonry is the main building material with poor physical and chemical adaptability. The cement material used in ancient Chinese city walls is mainly lime. At present almost all masonry monuments in Europe and America use lime as the base material for restoration. Based on this situation, hydrated lime has been paid more and more attention as a new material for the protection of cultural relic buildings. According to the European standard EN-459, hydrated lime was prepared by blending each raw material. Firstly, the effects of mass ratio of lime-white cement, heavy calcium micro-powder and active micro-powder on the physical and mechanical properties of the cementing system were systematically studied, including water absorption, softening coefficient, compressive strength and flexural strength. The optimum ratio L1: lime: White cement: bicalcium micropowder: active micropowder 27: 36: 27: 10 was determined. The flowability of mortar was 185mm / 28d and the compressive strength was 7.3IMPa0.The softening coefficient was 0.66. On the basis of this, the effects of three additives, such as aluminum additive, polypropylene fiber and stone pile, on physical and mechanical properties of hydraulic lime reference ratio L1 and early drying shrinkage of 28d were studied. The results showed that the strength of mortar increased by 19.4% compared with the reference mortar, and the early drying shrinkage decreased by 33% with the addition of 1% 1% aluminum additive, and the strength of mortar added with polypropylene fiber had little effect on the early drying shrinkage of mortar. The addition of stone velvet increased the drying shrinkage by 16 / 32 and the compressive strength decreased first and then increased. Secondly, the carbonation process of hydrated lime was studied by accelerated carbonization test, and the shear bond strength and tensile bond strength of hydrated lime were also studied in this paper. The shear bond strength of the standard proportioning sample is 0.186 MPA, which is higher than that of the traditional cement mortar and lime mortar (0.069 MPA / 0.022 MPA), and the tensile bond strength is 0.114 MPA / a. The test meets the "reversibility" requirement of the ancient wall restoration mortar. In addition, based on the durability test method of concrete, the durability of hydrated lime mortar under freeze-thaw environment, total soaking of sulfate and coupling of sulphate-dry and wet cycle is studied. The results show that the durability of hydrated lime is better than that of traditional lime mortar (after carbonization). But the frost resistance is not good. Finally, the microstructure and microstructure of hydrated lime, hydration products and pore structure of mortar were measured by scanning electron microscopy (SEM) and XRD- MIP technique, and the early hydration process and microstructure formation process of hydrated lime were analyzed by hydration heat method.
【学位授予单位】：东南大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TQ177.27

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