北方地区沥青混凝土路面的裂缝与防治

公路在使用过程中,路面会因行车荷载、环境因素等作用逐渐产生破坏,裂缝是最为常见的破损形式之一,尤其北方地区环境恶劣,不同季节温差很大,高速公路的主要病害就是裂缝,目前我国沥青路面裂缝修补技术主要用热沥青以表面填缝为主,抗渗水能力不好,低温抗裂性较差。国外同种裂缝修补材料性能较好,但是施工器械很复杂,需要专用的设备来施工,而且造价高。对裂缝对沥青混凝土路面的影响,北方地区沥青混凝土路面裂缝常见类型、沥青混凝土路面裂缝的表现形式、北方地区沥青混凝土路面裂缝的防治措施等进行了分析探讨。     

潘家口电厂下池大坝混凝土缺陷大修施工技术

文章介绍了潘家口电厂下池大坝混凝土缺陷的施工方案,主要包括混凝土冻融剥蚀破损修补、伸缩缝剥蚀破损修补、混凝土裂缝处理及混凝土表面涂刷SK手刮聚脲施工工艺处理等。     

沥青路面裂缝填封修补的再破损分析及其防治

通过对再破损的产生原因分析能够掌握其防治与改善途径,针对沥青路面裂缝修补的填封修补再破损,根据其内涵确定了三种表现类型,并具体分析了各自可能产生的原因,结合裂缝填封的受力变形分析,提出了室内试验选材控制要求方面及防治裂缝填封再破损的技术措施。     

混凝土结构裂缝、劣伤、缺陷外观检查及应用JVS聚合物水泥结构胶泥修补加固

本文通过对混凝土结构裂缝、缺陷等的检查评估 ,选用适宜的修补加固材料和方法 ,介绍裂缝的分类和产生的原因以及如何诊治 ;并介绍通用修补加固材料的特性以及其适用的修补方法和部位。使其取长补短 ,既达到修补加固的目的 .又经济合理     

混凝土裂缝修补过程中新材料的作用

混凝土裂缝是建筑工程中一种常见的问题,混凝土裂缝直接影响到了工程质量,为此,需要对其进行修补。在混凝土裂缝修补过程中,选择合适的修补材料对提高混凝土性能有着重大作用。本文就混凝土裂缝修补过程中新材料的作用进行了相关的分析。     

混凝土裂缝的处理方法与常用材料

在建筑工程的混凝土施工中,混凝土裂缝是最常见的一个问题,其对工程有着深远的影响。为此,本文通过对施工中混凝土裂缝产生的原因及其分类进行分析,提出在修补混凝土裂缝时,一些常用的材料和具体的处理方法。进一步提出如何预防施工中混凝土裂缝产生的具体措施。     

混凝土裂缝产生的材性分析和修补材料研究

混凝土作为一种多相复合基材料,裂缝产生的原因很多。主要从材性上分析了裂缝产生和发展的原因。并分析了裂缝修补材料的选取原则。结果表明,修补材料的材性和基体材料的材性需要有效协调,以避免产生二次裂缝。     

混凝土裂缝封堵材料的研究

０前言混凝土材料是一种脆性非均质的工程材料 ,其内部存在大量微细裂缝和不同大小的孔隙 ,抗拉强度低 ,抗裂性差 ,混凝土结构物很容易产生裂缝。因此混凝土出现裂缝不但降低了结构的耐久性和防水性 ,而且也给结构整体性和外观造成不良影响。混凝土裂缝如不及时修补 ,将会加剧裂缝的进一步发展 ,以至于使钢筋锈蚀 ,并有可能促使结构的破坏。大部分混凝土裂缝由地基不均匀沉降、混凝土材料收缩、施工温差应力等原因产生的混凝土结构变形所引起 ,如能及时修补 ,将不影响结构原有功能 ,甚至不降低其使用寿命 ,同时也可避免因拆除重建而造成的巨…     

混凝土裂缝及灌浆修补材料的研究与应用

混凝土作为一种多相非均匀复合材料,很多因素都可以引发裂缝的产生。本文探讨了造成混凝土裂缝的主要原因,阐述了化学灌浆材料修补混凝土裂缝应当具有的力学性能、稳定性及耐久性能,并结合实践经验介绍了环氧树脂灌浆修补混凝土裂缝的施工技术。     

压力注浆法修补混凝土裂缝材料试验研究

我国西北地区气候复杂多变,施工过程中混凝土裂缝等质量通病极易产生。本文针对西北地区气候干燥、低温、温差大、日照强、风沙大等自然环境特点,对混凝土裂缝修补材料进行试验研究,确定较能满足西北地区的裂缝修补材料。     

钢纤维混凝土修补机场破损道面的方法研究

改革开放以来,我国的航空事业得到了前所未有的发展.近些年,我国机场建设发生了新的变化,即新建机场逐年减少,老机场的维修和改造、扩建则比较迫切.结合十几年工程实践经验,提出采用钢纤维混凝土修补破损机场道面.用钢纤维混凝土这一新型高强复合材料修补破损的机场水泥混凝土道面,既可提高机场道面的抗裂性、抗弯曲、耐冲击和耐疲劳性,而又改善了机场水泥混凝土道面的使用性能,延长使用寿命,对节工程造价等具有重要的经济效益和社会效益;为提高机场道面补强与改造提供了良好的途径.     

水泥混凝土路面快速修补材料的研制

利于硫铝酸盐水泥和普通硅酸盐水泥及高效减水剂等配制水泥混凝土路面的快速修补料,根据路面修补的要求配制了修补混凝土和修补砂浆,并测定了修补材料的抗压强度,水化放热,磨耗量等指标,分析了修补材料的特点和施工工艺要求,可以应用于水泥混凝土路面的修补。     

Cylindrical specimen for measuring shrinkage in repaired concrete members

This study presents a new method for measuring the shrinkage of repair materials in repaired concrete structures. Three cylindrical models and a half-scale beam were constructed; these included three types of repair materials and three types of interface surfaces between substrate and repair materials. The unrestrained shrinkage of repair materials was measured and compared with that of restrained samples. The proposed cylindrical model with a smooth concrete interface had the best conformity with the beam model for all repair materials. This new model can be considered for prediction of the real shrinkage in repaired structures.     

《混凝土裂缝修补灌浆材料技术条件》编制解读

介绍了建筑工程行业产品标准《混凝土裂缝修补灌浆材料技术条件》的编制背景、编制原则、编制过程和标准的主要内容概述,并重点对混凝土裂缝修补灌浆材料的灌注性能、体积收缩率、与混凝土的相容性进行了说明。标准的编制对规范混凝土裂缝修补灌浆材料的生产和使用,保证混凝土裂缝修补工程质量等方面具有指导意义。     

Concrete bridge deterioration: Research into the problem by the TRRL

Recent research on the problems caused by de-icing salt penetration into concrete bridges is reviewed. The author discusses comparative studies of bridges of different ages, the detection of defects, crack repair, concrete repair materials, bridge deck waterproofing, protective coatings and cathodic protection.     

Field performance evaluations of partial-depth repairs

Before partial-depth repair using proper materials was implemented, Houston District of Texas Department of Transportation had to repair spalls and punchout constantly in the Continuously Reinforced Concrete Pavement (CRCP) pavements on US290 and SH6. The full-depth repair to address the cracking on US75 did not work well. Spalls, wide, cracks and punchouts due to mid-depth horizontal cracks represent functional and structural distresses in Portland cement concrete pavement. Traditionally, these distresses were repaired by partial-depth repair (PDR). The performance of PDR varies substantially. Two types of polymeric patch materials were used to repair the distresses. Material A is polyurethane-based and Material B is epoxy-based. Material A was used to repair spalls in CRCP. It provided quite satisfactory performance for more than 9 years. Material B was used to repair cracks in jointed concrete pavement and CRCP. Its performance was satisfactory when applied to stable slabs and the loose concrete was completely removed. Compared to full-depth repair (FDR), PDRs utilizing polymeric patch materials are much more cost-effective, and PDR takes much less time than FDR. It is believed that both chip-and-patch and saw-and-patch methods would work as long as the delaminated areas are completely removed and the concrete slabs are stable (e.g. no settlement or movement under moving trucks).     

How to make today’s repairs durable for tomorrow — corrosion protection in concrete repair

The future of the concrete repair industry appears to be promising and bright, judging from the projections based on current trends in repair, rehabilitation, restoration and strengthening of existing infrastructure. However, this optimism must be tempered in light of the need to change the image of the industry as one that is often self-serving — the industry that is repairing the repairs. Due to the increasing public concern with durability of concrete structures in general, and repaired concrete structures in particular, the subject of steel corrosion and corrosion protection in repaired concrete structures is discussed with reference to the deficiencies in our knowledge of corrosion and corrosion protection in concrete repair, methods of testing, and in the science of repair durability.     

Schutz und Instandsetzung von Betonbauteilen mit genormten Produkten nach EN 1504

Repair and protection of concrete structures using products according to the standard EN 1504 The European series of standards EN 1504 for protection and repair of concrete structures is actually more or less finished. It consists of 10 main standards and 62 European test standards. The main standards EN 1504‐2 to 7 refer to the product classes surface protection systems, mortars, adhesives for strengthening, materials for filling of cracks and voids, anchoring products as well as protection materials for the steel surface. The principles for the use of the products and systems as well as the application of the products on site including quality assurance are regulated in parts 9 and 10. Furthermore the quality assurance for the products is described in part 8. In this way within the next months an extensive set of standards for protection and repair of concrete structures is available. Actually it is discussed, how this set of standards will be introduced in Germany. Due to different reasons it has been decided, that the parts for design and application will not be introduced in Germany, because the existing standards of the DAfStb “Protection and repair of concrete structures” as well as the ZTV‐ING have been used successfully for several years. To be able to use the European CE‐marked products for protection and repair of concrete structures in future in Germany, for surface protection, mortars, materials for filling of cracks and voids as well as steel coatings in the meantime additional standards (DIN V 18026 to 18028) have been worked out, while the adhesives and anchoring products will be handled via approvals as before. This paper describes, how protection and repair of concrete structures will be carried out in Germany with CE‐marked products according to EN 1504.     

固体废弃物在蒸压加气混凝土中的利用与研究进展

大宗工业固体废物的量在逐年增加,占用环境资源,由于处理不当给社会生产带来了严重的环境问题。相关研究表明,大部分固体废物的成分中含有大量的SiO2和Al2O3等有效成分,可作为硅质材料投入蒸压加气混凝土生产使用。综述搜集了各种固体废物在蒸压加气混凝土中的应用研究,并对各种固体废物进行分类,分析固体废物应用于蒸压加气混凝土生产的可行性,并提出了当下存在的问题以及未来的方向。     

On the effect of time-dependent deformations on the behaviour of patch-repaired reinforced concrete short columns

This paper reports the results of an experimental study of the effect of time-dependent deformations (such as shrinkage and creep) of concrete repair materials on the ability of patch repairs to contribute to the structural function of reinforced concrete short columns. Prior to repair, strain measurements were taken from loaded columns with preformed cavities; cavity depths varied between columns. One polymeric and one polymer-modified concrete repair material were used for repair, all repairs being performed under zero load. After repair, the distribution of strain was measured from columns subjected to axial service load and from similar columns observed under zero load. Test results indicate that in the short term both the repair materials assist the repaired column to carry load, but in the long term the contribution of the polymer-modified material is reduced substantially while that of the polymeric material is sustained. It is observed that shrinkage of the repair material can induce bending in the repaired column and that this bending increases with patch repair cavity depth. Within the repaired zone, bending strain distributions were linear which would suggest that conventional methods of structural analysis are appropriate for such members.