Improving the performance of ground-supported slabs subjected to extreme environmental conditions using rigid high strength fiberglass geogrids

一个日益令人担忧的问题是，直接放置在地面上的结构构件在恶劣的室外环境条件下迅速退化。例如，人行道通常由混凝土板组成，通常暴露在极端天气和腐蚀性条件下(例如冬天的除冰盐)。加拿大大约有10万公里的人行道，每年约有20%的人行道需要更换，估计成本超过10亿美元。市政财政资源有限，没有足够的资金来跟上日益恶化的基础设施的步伐。标准做法是使用未加固或名义上钢筋加固的混凝土人行道来控制裂缝宽度。然而，在除冰盐、海水、海洋空气等中发现的含有氯化物的化学物质的存在，可能会破坏将混凝土结合在一起的粘结剂，并导致钢筋腐蚀。过去有人尝试使用传统的聚合物土工格栅作为混凝土加筋材料，但聚合物土工格栅的延性导致变形过大，整体性能较差。泰坦环境保护有限公司正与麦吉尔大学合作，研究使用高强玻璃纤维(Conforce)土工格栅材料加固地面支撑混凝土结构的效率。在联盟拨款的支持下，该项目将为其他土工格栅的应用铺平道路，并促进更多的大学合作。在麦吉尔大学进行的初步指数测试表明，破坏时的诱导应变约为1%，约为聚合物土工格栅的七分之一。此外，泰坦在艾伯塔省新人行道上进行的试点现场测试结果显示，结果令人振奋。预计这项研究的结果将有助于工程师设计更可持续的地面支撑结构。这项研究对加拿大很重要，因为建议的建造方法可以显著延长这些结构的使用寿命。这项研究拨款将有助于培养一名博士、一名硕士和两名本科生。

A problem of growing concern is the fast deterioration of structural elements placed directly on the ground and subjected to harsh outdoor environmental conditions. For example, sidewalks are typically made out of concrete slabs that are usually exposed to extreme weather and corrosive conditions (e.g. de-icing salts in winter). There are about 100,000 km of sidewalks in Canada with about 20 percent in need of replacement in a given year at an estimated cost of more than $1 billion. Municipal financial resources are limited and there are insufficient funds to keep pace with the deteriorating infrastructure. The standard practice is to build most concrete sidewalks using unreinforced or nominally steel-reinforced for crack-width control. However, the presence of chemicals containing chlorides, found in de-icing salt, ocean water, marine air, etc., can attack the bonds that hold concrete together and contribute to steel corrosion. Attempts have been made in the past to use conventional polymeric geogrid as concrete reinforcement material, however, the ductile nature of polymeric geogrid resulted in excessive deformation and overall poor performance.Titan Environmental Containment Ltd. is teaming up with McGill University to investigate the efficiency of using high strength fiberglass (ConForce) geogrid material to reinforce ground-supported concrete structures. Supported by Alliance grant, this project will pave the way for other geogrid-reinforced applications and promote more university collaboration. Preliminary index tests performed at McGill University indicated that the induced strain at failure is about 1%, which is about one-seventh of that of polymeric geogrid. In addition, the results of pilot field tests done by Titan on new sidewalks in Alberta showed promising results. It is expected that the results of this study will help engineers in designing more sustainable ground supported structures. This study is of importance to Canada as the proposed construction approach could significantly enhance the service life of these structures.This research grant will contribute to the training of one PhD, one MSc, and two undergraduate students.