Characterization of DURA-preblended UHPC for bridge construction according to the CHBDC standards

根据 CHBDC 标准表征用于桥梁施工的 DURA 预混 UHPC

• 批准号: 540548-2019
• 负责人: Pantazopoulou, Stavroula
• 金额: $ 1.82万
• 依托单位: York University
• 依托单位国家: 加拿大
• 项目类别: Engage Grants Program
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=680349
• 关键词: Characterization; DURA; preblended; UHPC; bridge

Ultra High Performance Concrete (UHPC) is an emerging class of very resilient fiber reinforced cementitious materials that can be used to mitigate the durability and limited-service life issues faced by Canadian Bridges and other infrastructure exposed to aggressive environments. Due to dense packing, UHPC has very few connected capillary pores so that ingress and diffusion of water and chlorides is much slower than in conventional concrete; distributed steel fibers with a high aspect ratio delay the occurrence of crack localization enabling spectacular tensile strain capacity without strength loss. In the Canadian Market there are only few available UHPC products whereas the Canadian Highway Bridge Design Code Committees are engaged in establishing procedures for quality control of UHPC materials for implementation in bridge construction- the draft document, known as Annex S(A23.1) is about to be enforced. Facca is a Canadian Company that produces a unique material, DURA-UHPC, produced entirely with raw materials quarried in Canada. The challenge faced by the industrial partner in order to use DURA-UHPC in bridge construction is to demonstrate through physical modeling of mechanical and aggressive exposure conditions in the lab, that the material can stand the test of time and meet the objectives of 100-year long service life of bridge construction. But the testing procedures are not fully understood in terms of sensitivity and relevance to the true field performance of UHPC, so this is a field of ongoing research. Some of the required tests are challenging to conduct or require special expertise and testing facilities. As the official introduction of UHPC in the Code Standard is very new, it is challenging to find organizations that have the resources needed to conduct and assess the accuracy and relevance of the entire collection of prescribed mechanical and durability tests. The research challenge targeted by the PI is to proof test and if necessary, fine-tune, through calibration with DURA-UHPC, the draft testing procedures for UHPC materials that are about to be introduced in the Code. The research will meet the objectives of both partners, and will provide insights for optimizing the material and testing protocols.

超高性能混凝土 (UHPC) 是一种新兴的高弹性纤维增强水泥材料，可用于缓解加拿大桥梁和暴露在恶劣环境中的其他基础设施所面临的耐久性和有限使用寿命问题。由于UHPC的堆积致密，连通的毛细孔很少，因此水和氯化物的进入和扩散比传统混凝土慢得多；具有高纵横比的分布式钢纤维延迟了裂纹局部化的发生，从而在不损失强度的情况下实现了惊人的拉伸应变能力。在加拿大市场上，可用的 UHPC 产品很少，而加拿大公路桥梁设计规范委员会正在制定用于桥梁施工的 UHPC 材料质量控制程序 - 名为附件 S(A23.1) 的文件草案即将实施。 Facca 是一家加拿大公司，生产独特的材料 DURA-UHPC，完全采用加拿大开采的原材料生产。工业合作伙伴在桥梁施工中使用 DURA-UHPC 时面临的挑战是，通过实验室中机械和侵蚀性暴露条件的物理建模来证明该材料能够经受住时间的考验，并满足桥梁施工 100 年长使用寿命的目标。但测试程序在灵敏度和与 UHPC 真实现场性能的相关性方面尚未完全了解，因此这是一个正在进行的研究领域。一些所需的测试很难进行，或者需要特殊的专业知识和测试设施。由于规范标准中对 UHPC 的官方介绍非常新，因此找到拥有进行和评估整个规定机械和耐久性测试集合的准确性和相关性所需资源的组织具有挑战性。 PI 面临的研究挑战是验证测试，并在必要时通过 DURA-UHPC 校准对即将在规范中引入的 UHPC 材料测试程序草案进行微调。该研究将实现合作双方的目标，并将为优化材料和测试方案提供见解。