1) Prestressed HPSFRC structural elements; 2) Seismic design of rectangular concrete bridge piers; 3) Advanced nonlinear modelling of concrete structures

拟议的研究计划包括三个研究项目，它们是正在进行的项目的直接延续。所有的研究项目都结合了实验室测试和分析方法。 (1)预应力高性能钢纤维混凝土结构构件设计。该项目的主要目标是为HPSFRC的结构使用开发一种设计方法和相关的材料测试。它遵循了最近的国际建议中对加固的SFRC构件所采用的理念。该项目涉及预应力混凝土梁在使用荷载和极限荷载作用下的受弯设计。 (2)矩形混凝土桥墩设计。本工程旨在完善矩形和墙式桥墩双向地震作用下的设计规范。在最近的一个项目中确定了将最小纵向配筋率降低到当前规范规范以下的可能性。重新讨论了有关钢筋细节的抗震条款，以确保矩形横截面的适当混凝土约束。研究了高性能和超高性能钢纤维混凝土在塑性铰区的应用。 (3)混凝土结构的高级非线性建模。该项目的总体目标是为研究和工程界提供一个稳健和有效的非线性有限元三维本构模型，用于预测混凝土结构的服役行为、极限强度和破坏机理。研究活动的重点是开发一个在设计中使用非线性有限元分析的可靠性框架。该模型与前两个项目并行使用、开发和验证。

The proposed research program includes three research projects that are in direct continuation of ongoing projects. All of the research projects combine laboratory testing and analytical approaches. (1) Design of prestressed high performance steel fibre reinforced concrete (HPSFRC) structural elements. The main objective of the project is to develop a design methodology and the associated material testing for the structural use of HPSFRC. It follows the philosophy adopted for reinforced SFRC elements as proposed in recent international recommendations. The project addresses the design of prestressed concrete girders in flexure under service loads and at ultimate. (2) Design of rectangular concrete bridge piers. This project is aimed at improving the design specifications for rectangular and wall type bridge piers subjected to bidirectional earthquake components. The potential of reducing the minimum longitudinal reinforcement ratio below the current code specifications was identified in a recent project. Seismic provisions regarding reinforcement detailing for ensuring proper concrete confinement for rectangular cross sections are revisited. The use of high and ultra-high performance SFRC in the plastic hinge region is investigated. (3) Advanced nonlinear modelling of concrete structures. The general objective of the project is to provide research and engineering communities with a robust and validated nonlinear finite element 3D constitutive model for predicting the behaviour in service, and the ultimate strength and failure mechanisms of concrete structures. The research activities focus on developing a reliability framework for the use of nonlinear FE analysis in design. The model is used, developed and validated in parallel with the first two projects.