【作者】 刘腾飞；

【导师】 胡昱；

【作者基本信息】 清华大学 ， 水利工程， 2011， 硕士

【摘要】 水泥基渗透结晶型防水材料（CCCW）作为绿色环保的防渗堵漏新材料，不仅具有防水抗渗功能，还具有裂缝修复、抗冻、抗碳化等多种优良特性，被广泛应用于地下洞室、水库大坝、道路桥梁的防水抗渗和裂缝修补。本文通过实验验证了XYPEX渗透结晶型防水材料对混凝土的自愈性、抗冻性和抗压强度三方面性能的影响，并利用扫描电镜和能谱仪分析XYPEX水化产物，结合其组成成分，分析组分所发挥的作用。实验结果显示：（1）外涂XYPEX浓缩剂对提高混凝土抗冻性有明显效果，混凝土本体龄期和XYPEX的养护方式对其抗冻效果有影响。XYPEX对提高早龄期混凝土的抗冻性的帮助效果更大，且泡水养护比洒水养护对提高混凝土抗冻性更有利。（2）混凝土本身具有自愈性，缝宽、养护条件等对自愈合产物大小和数量有影响。使用XYPEX时，在水分充足条件下，水化产物中出现大量针状、棒状、纤维状晶体错综交织，呈空间网状分布，有利于堵塞、密实孔隙和裂缝。（3）混凝土的自愈性使其受到破坏产生裂缝后强度能够有所恢复。受压破坏龄期、预压应力水平及养护方式对养护后的最终强度都有一定程度的影响。表面使用XYPEX处理时没有体现出XYPEX对混凝土力学性能的修复作用，可能是由于本文实验中XYPEX是在表面使用而不是内部掺和缘故所致，致使短期内无法渗透到内部对微裂纹产生修复作用。（4）提出了一种利用能谱仪检测经过XYPEX处理的砂浆试件中Na元素强度的方式来评价XYPEX渗透深度的新方法，实验结果发现，XYPEX的渗透深度随基层砂浆龄期的增大而增大，随基层砂浆内部含水量的增大而增大。（5）水的存在是CCCW是发挥作用的必备条件。XYPEX防水材料的主要成分具有较高的膨胀性和碱性，自身组分间或与混凝土中未水化水泥发生碱-硅酸反应生成凝胶体或晶体，可迅速填充孔隙或裂缝。通过扫描电镜观测到多种Mg、Na等元素的晶体，如水化硅酸钠。此外，碱性氧化物溶于水后创造出的较高碱性环境也为各种膨胀结晶反应的发生创造了有利条件。更多还原

【Abstract】 As a kind of green and enviromental materials used for anti-seepage andplugging, Cementitious Capillary Crystalline Waterproofing Materials(CCCW)was widely used in underground structure, reservior, dam, road and bridgeengineering with not only waterproof and permeability resistance, but alsoexcellent performance of crack repair, frost resistance, carbonation resistance.This paper presents the effect of XYPEX on self-healing, frost resistance andcompressive strengh of concrete through experiments and analyzes thefunction of components of XYPEX(a kind of CCCW) through the observedhydration products with SEM and EDS. The result suggests:(1)Surface treatment of concrete with XYPEX is helpful of improvingconcrete’s frost resistance. It has been found that the age of concrete andcuring way of XYPEX would impact the antifreeze effect. XYPEX providesmore help for early aged concrete and the immersion way is better thanaspersion on improving frost resistance(2)Concrete with cracks has self-healing property while the crackwidth and curing way has effect on the size and amount of self-healingproducts. There are many needle-shape, rod-shape and fibre-shape crystalsinterweaving together with sufficient water forming a space net structurewhen XYPEX is used. These products as mentioned would effectively fill andcompact the pores and cracks.(3)The self-healing property would make concrete’s strength recoverafter it was destroyed. The age of concrete when compressed and curingway after destroyed have effect on the final compressive strength. XYPEX hasno effect on the recovery of mechanical performance of concrete. It ispossibly resulted by the position of XYPEX. The position is not internal buton the surface of concrete specimens so that XYPEX cannot permeate intoconcrete in a short period of time. (4)A new method is proposed for evaluating the penetration depth ofXYPEX through detecting the sodium’s intensity of mortar specimens treatedwith XYPEX. It has been found that the penetration depth would increase withthe age and internal water content of mortar specimens.(5)The presence of water is a necessary condition for applications ofCCCW. The main composites of XYPEX have high expansibility andalkalinity. It may occur alkali-silicate reaction in XYPEX itself or betweenXYPEX and unhydrated cement of concrete and the formation of gel andcrystalline, such as NaSiO3·nH2O has been observed by SEM, can fill poresand cracks rapidly. Additional, alkaline oxide dissolved in water can create abasic environment and make a favorable condition for various expansioncrystallization reactions.更多还原