2019 CSCE Annual Conference - Laval (Greater Montreal)

2019 CSCE Annual Conference - Laval (Greater Montreal) Conference


Title
Preliminary Design Guidelines and Optimization of UHPC Blast Walls for Different Scaled Distances

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Author(s)
Mr. Mohtady Sherif, Ryerson University (Presenter)
Ms. Hesham Othman, Ryerson University
Dr. Hesham Marzouk, Ryerson University
Abstract

Ultra High Performance Fiber Reinforced Concrete UHPFRC, is the latest generation of structural concrete, having an outstanding fresh and hardened concrete properties, this includes the ease of placement and consolidation with ultra-high early and long term mechanical properties, as well as toughness volume stability, durability, higher flexural and tensile strength and ductility. The research demand on the special applications of the UHPFRC is growing higher, the material behavior, characteristics are getting more understood as more research is being focused on it. One special application that UHPFRC is thought to have an outstanding performance at is in the field of defensive structures, and protective shields, specifically against blast loads.

 This paper presents part of a study that is concerned with the behavior and response of UHPFRC wall panels under blast load, where a parametric study on the response of a 200MPa UHPFRC under blast loads was conducted using finite element modelling, the parameters being tested were the thickness ranging from 100 mm to 300 mm at 25mm increments, in addition to the reinforcement ratio of 0%, , 0.2%, 1%, 3%, the aspect ratio of 1, 1.5 and 2, and the boundary condition from 4 edges restrained once fixed, once pinned, and 4 edges restrained once fixed, once pinned, and one edge fixed restrained.   The aim is to present a better understanding of influence of the design parameters on the behavior of UHPFRC wall panels under blast loads. Moreover, to set guidelines and charts for selecting the optimum wall panel for a specific blast load environment and scaled distance, also to set the foundation for further investigation of the response different UHPFRC wall panel assemblies.

 The numerical simulation has been performed using ABAQUS/Explicit, with a concrete material model which considers the contribution of tensile hardening response and strain rate effect. Fracture energy and crack-band width approaches are combined to accurately represent the tensile behavior and guarantee mesh independence of results. The complete behavior of UHPFRC is defined using concrete damage plasticity model. the blast load is applied using the Conventional Weapons ConWep method of the US Army Corps of Engineers USACE that is built into ABAQUS/Explicit. The validity of the numerical model used is verified by comparing numerical results to experimental data.