【作者】 王亮；

【导师】 李鹏飞；

【作者基本信息】 重庆交通大学 ， 水利工程（专业学位）， 2024， 硕士

【摘要】 混凝土在诸多因素的作用下往往会发生开裂,裂缝的产生势必会导致混凝土力学性能、耐久性能的下降。因此,保证混凝土的性能和减少修补裂缝所带来的人力物力具有非常重要的意义。研究水泥基渗透结晶型防水材料在提高混凝土裂缝自愈合性能方面的效果以及对混凝土性能的影响和作用机理具有重要意义。本文选取了三种不同掺配方式的水泥基渗透结晶型防水材料,通过宏观和微观试验,探究了渗透结晶材料对无损伤混凝土、裂缝自愈合性能以及不同损伤类型下混凝土自修复性能的影响,并深入分析了渗透结晶材料提升混凝土性能的自修复机理。本文主要研究成果如下:(1)添加渗透结晶材料对无损伤混凝土的改性效果显著,相较于空白组试件,渗透结晶材料的掺入使得试件的抗压强度和劈裂抗拉强度均得到了明显提升。同时,掺入渗透结晶材料的试件也表现出更高的抗碳化性能和早期开裂性能,特别是初始内掺液体型混凝土试件E2-N2表面基本看不见清晰的裂缝,说明了内掺液体型混凝土的早期抗裂性能最好,掺入渗透结晶材料能够显著的降低单位面积的总开裂面积。(2)无论是标准养护还是水浸养护,随着时间的增加,各组预制裂缝试件的渗水率均有所下降,掺入水泥基渗透结晶型防水材料的试件在经过28d养护后有着更小的渗水率,表明渗透结晶材料有助于提升混凝土的裂缝自愈合能力。对比两种养护条件,发现在水浸养护下,渗水率表现出更大的下降幅度,说明浸水养护的自愈合性能要优于标准养护,具有更好的修复效果。(3)通过水压力损伤、冻融损伤、荷载损伤自修复性能试验,表明渗透结晶材料的掺入增强了混凝土试件的自修复能力。对于不同类型的损伤,经过养护后,掺入渗透结晶材料的试件有着较高的修复性能,具有较强的水压力、冻融、荷载损伤自修复能力比,降低了这些损伤类型对混凝土的损害,同时,提高了其对混凝土的自修复性能,使得性能得以修复。(4)微观试验表明,混凝土自修复性能的提升是由于渗透结晶材料中的活性物质促进了水化反应,生成了大量的愈合产物,使得混凝土内部结构存在较多的水化硅酸钙和碳酸钙晶体,这些愈合产物不断填充了混凝土的孔隙和裂缝,使其内部结构更加致密,有着较优的混凝土性能以及裂缝自修复性能。更多还原

【Abstract】 Concrete is often cracked under the action of many factors,the cracks will inevitably lead to the mechanical properties of concrete,durability decline.Therefore,it is of great importance to ensure the performance of concrete and reduce the human and material resources brought about by the repair of cracks.It is of great significance to study the effect of Cementitious Capillary Crystalline Waterproofing Materials(CCCW)in improving the self-healing performance of concrete cracks,as well as the influence and mechanism of action on the performance of concrete.In this thesis,three kinds of cementitious osmotic crystalline waterproofing materials with different mixing methods were selected,and the effects of osmotic crystalline materials on undamaged concrete,crack self-healing performance,and self-healing performance of concrete under different types of damages were investigated through macroscopic and microscopic experiments,and the self-healing mechanism of osmotic crystalline materials for enhancing the performance of concrete was analyzed in depth.The main research results of this paper are as follows:(1)The addition of osmotic crystalline material had a significant effect on the modification of undamaged concrete,and compared with the specimens of the blank group,the incorporation of osmotic crystalline material led to a significant increase in the compressive strength and splitting tensile strength of the specimens.At the same time,the specimens mixed with osmocrystalline materials also showed higher carbonation resistance and early cracking performance,especially the initial liquid-type concrete specimen E2-N2 surface basically could not see clear cracks,which indicated that the liquid-type concrete mixed with the best early cracking resistance,and the mixing of osmocrystalline materials could significantly reduce the total cracking area per unit area.(2)Whether it was standard curing or water immersion curing,with the increase of time,the water penetration rate of each group of prefabricated crack specimens decreased,and the specimens mixed with cementitious osmotic crystalline waterproofing materials had a smaller water penetration rate after 28 d curing,which indicated that the osmotic crystalline materials could help to improve the self-healing capacity of cracks in concrete.Comparing the two curing conditions,it was found that the water penetration rate showed a greater decrease under the water immersion curing,indicating that the self-healing performance of the water immersion curing was better than that of the standard curing,and had a better repair effect.(3)Through the water pressure damage,freezing and thawing damage,and load damage self-healing performance test,it showed that the incorporation of osmotic crystalline materials enhanced the self-healing ability of concrete specimens.For different types of damage,after curing,the specimens mixed with osmocrystalline materials had high repair performance with strong water pressure,freeze-thaw and load damage selfhealing ability ratio,which reduced the damage of these damage types to the concrete,and,at the same time,improved its self-healing performance to the concrete,which enabled the performance to be repaired.(4)Microscopic tests showed that the improvement of concrete self-healing performance was due to the active substances in the osmotic crystalline materials to promote the hydration reaction,generating a large number of healing products,so that the internal structure of the concrete existed more hydrated calcium silicate and calcium carbonate crystals,and these healing products continue to fill up the pores and cracks in the concrete,so that the internal structure of the concrete was more dense,and it had better concrete performance and crack self-healing performance.更多还原