【作者】 金少春；

【导师】 高培伟；

【作者基本信息】 南京航空航天大学 ， 道路与铁道工程， 2009， 硕士

【摘要】 混凝土道面经受长期自然环境及荷载作用,会出现大量宽度小于0.2mm的微细裂缝,如不及时修补,外部侵蚀介质易进入混凝土内部,加剧道面破坏,影响耐久性和安全性。本文针对混凝土道面微细裂缝的高强、固化快、低收缩及稳定性的修补要求,根据可灌性、固化时间、收缩变形、粘结强度及稳定性指标,对新型微细裂缝修补材料进行改性研究,同时对其性能和改性机理进行了探讨,研究结果表明:(1)根据固化时间、收缩变形、粘结强度、可灌性研究最佳改性材料种类和掺量。研究表明:使用有机材料Ya,82min时完成固化;使用有机材料Yb、Yc,固化时间较长,粘结强度大小关系是:Yc(D)<Yb(D)<Ya(D);Wa、Wb、Wc的加入,修补材料固化时间基本保持不变;在修补材料中加入Wa的粘结强度优于Wb和Wc;修补材料添加25%Ya和10%Wa的体积收缩不大于1.85%,且趋于恒定值1.80%;添加有机改性材料Ya后,渗入深度为17.1~21.5cm,添加无机改性材料Wa后,渗入深度范围是14.0~19.5cm,最佳的改性材料掺量是25%Ya和10%Wa。(2)通过对比修补材料改性前后的拉伸、弯曲强度和变形量,对其力学性能进行了研究。研究表明:添加25%Ya的修补材料强度基本不变,抗拉和抗弯曲变形能力提高了4.99倍和0.77倍;添加25%Ya和10%Wa的修补材料强度有所提高(拉伸2.29%,弯曲5.29%),同时抗拉和抗弯曲变形能力提高了4.85倍和0.90倍。(3)通过抗老化、抗冻性、抗腐蚀试验,研究其稳定性能。研究表明:修补材料改性后的拉伸和弯曲强度保持率均高于修补材料,保持率不小于95.10%,抗拉和抗弯曲变形能力提高了4.44倍和0.96倍,说明修补材料改性后具有较好稳定性能。(4)通过对修补材料改性机理简单探讨,发现修补材料加入Ya,形成Ya/修补材料IPN网络贯穿结构,这种结构增强修补材料聚合物分子链的活动性能,增强了键的联接,改善了界面结构,提高了修补材料的力学性能和耐久性能、增强了稳定性能。更多还原

【Abstract】 Many micro-cracks, e.g. less than 0.2mm in width occurred on surface of concrete pavement after long term exposure to natural environment and load. These cracks, if not mended in time, would form passes for external corrosives to the concrete, which would accelerate the breakage, and threaten the durability and safety of concrete pavement.In this paper, a new modified repair material for micro-cracks of concrete pavement was studied to meet the requirements such as high strength, rapid cure, low shrinkage and good stability. The performance and modification mechanism of the material were discussed. The main findings are as follows:(1) The type and content of modifier for the repair material based on curing time, shrinkage, bond strength and pouring. The results showed that: when an organic material Ya was used as modifier, curing process was completed in 82 min, and for Ya or Yc, longer curing time were required. The bond strength order is Yc(D)<Yb(D)<Ya(D). The addition of Wa, Wb, Wc can not chang the curing time significantly, and the bond strength of the repair material with Wa is better than the others. The shrinkage of the repair material with 25%Ya and 10%Wa is not more than 1.85%, tending to 1.80%. The penetration depth of the repair material with Ya is 17.1~21.5cm, and with Ya and Wa is 14.0~19.5cm. The optimal organic and inorganic type and content is 25% of Ya and 10% of Wa.(2) The mechanical performance of the material by comparing tensile and bending strengths before and after modification. The results showed that: there is little variation in strength after the addition of 25% Ya, but 4.99 and 0.77 times more than the repair material in anti-deformation capacity. There is an increment of strength (tensile 2.29%- bending 5.29%)of the repair material with 25%Ya and 10%Wa, 4.85 and 0.90 times more than the repair material in anti-deformation capacity.(3) The stabilities of the repair material have been investigated by aging, freezing-thawing durability and corrosion resistance. The results showed that: the tensile and bending strength of the repair material with modifier are more than the repair material, retention percentage not less than 95.10%, anti-deformation capacity of the repair material with modifier keep more than 4.44 and 0.96 times. The repair material with modifier could make the good stability performance.(4) The modification mechanism of the repair material has been discussed simply. The results showed that: the repair material after the addition of Ya forms interpenetrating polymer networks structure which enhances activity for the polymer molecular chains and coupling of bond, improves interface structure, improving mechanical performance and durability of the repair material, to enhance stability performance.更多还原