Performance of Ultra High Performance Fiber Reinforced Concrete Elements Subjected to Extreme Blast Loads

由于威胁的增加，确保加拿大城市的战略建筑具有抗爆能力变得越来越重要。有必要开发创新和成本效益高的方法，以确保爆炸事件期间可接受的性能。 材料科学的最新发展催生了新一代超高性能纤维增强混凝土(UHP-FRC)。与传统混凝土相比，UHP-FRC具有非常高的抗压强度、提高的抗拉强度、抗裂后抗裂性和韧性，使UHP-FRC成为用于抗爆结构设计的理想材料。在底层柱中，可以使用UHP-FRC来提高性能和防止连续倒塌。此外，UHP-FRC性能的改进可以放松细节，从而改善可施工性。超高韧性和抗碎裂性能还可用于设计优化的防爆墙体，可作为重要建筑物的有效防爆系统的一部分。 拟议研究的总体目标是减少与使用超高压-FRC结构系统的建筑结构上的爆炸荷载相关的危险。长期目标还包括开发在结构抗爆炸设计中使用超高强度纤维混凝土的设计和详细程序。短期内，该计划将重点关注UHP-FRC建筑柱和墙体构件的爆炸性能。为了评估柱子的爆炸性能，将使用渥太华大学最先进的激波管设备对半尺度试件进行模拟爆炸加载。柱子将受到各种爆炸压力组合的影响，目的是测试柱子在弹性、屈服和极限条件下的性能。同样，激波管测试也将在超高压纤维混凝土墙板上进行。试验变量将包括UHP-FRC材料特性、抗弯和横向钢筋特性(比率和强度)。作为分析程序的一部分，将基于在可变应变率下测试的小规模试件的大量材料试验，开发考虑动力效应的超高强度纤维混凝土的材料模型，并将评估和验证超高强度纤维混凝土柱和墙体在爆炸作用下的动力分析程序。 该研究项目将对UHP-FRC组件的爆炸性能进行创新性的实验和分析研究，并将为工程和研究界提供重要的数据和研究成果。六名研究生将接受培训，在该项目中接受培训的HQP将满足加拿大对精通建筑防爆设计的工程师日益增长的需求。该计划将是为UHP-FRC制定CSA S850爆炸设计指南的第一步，从而提高加拿大人的安全和保障。

Due to increased threats it is becoming important to ensure that strategic buildings in Canadian cities are blast resistant. There is a need to develop innovative and cost-effective methods that can ensure acceptable performance during blast events. Recent developments in material science have led to a new generation of Ultra High Performance Fibre Reinforced Concretes (UHP-FRC). When compared to conventional concrete UHP-FRC shows very high compressive strength, improved tensile strength, post-cracking resistance and toughness, making UHP-FRC an ideal material for use in the design of blast resistant structures. In ground-story columns, UHP-FRC can be used to improve performance and prevent progressive collapse. Moreover the improved properties of UHP-FRC can allow for relaxed detailing leading to improved constructability. Superior toughness and fragmentation resistance can also allow for the use of UHP-FRC in the design of optimized blast-resistant walls that can be used as part of an effective blast protection system for buildings of critical importance. The overarching aim of the proposed research is to mitigate hazards associated with blast loads on building structures using UHP-FRC structural systems. The long-term aims also include the development of design and detailing procedures for the use of UHP-FRC in the blast-resistant design of structures. Short-term the program will focus on the blast performance of UHP-FRC building columns and wall components. To assess blast performance of columns half-scale specimens will be subjected to simulated blast loading using the state-of-art shock-tube facility at the University of Ottawa. The columns will be subjected to a variety of blast pressure combinations aimed at testing the columns at elastic, yield and ultimate conditions. Similarly, shock-tube testing will also be conducted on UHP-FRC wall panels. Test variables will include UHP-FRC material properties, flexural and transverse steel reinforcement properties (ratio and strength) . As part of the analytical program, material models for UHP-FRC which incorporate dynamic effects will be developed based on extensive material testing on small-scale specimens tested under variable strain-rates, and procedures for the dynamic analysis of UHP-FRC columns and walls subjected to blast will be assessed and validated. This research program will result in innovative experimental and analytical research on the blast performance of UHP-FRC components and will provide the engineering and research community with important data and research findings. Six graduate students will be training and HQP trained in this program will meet increased demand for engineers that are well-versed in blast resistant design of buildings in Canada. The program will be a first step towards development of CSA S850 blast design guidelines for UHP-FRC, leading to improved safety and security for Canadians.