Performance evaluation of structural concrete with innovative reinforcement solutions

点击翻译按钮获取中文摘要

New types of concretes and reinforcements create opportunities for innovative structural designs; however, they also create challenges in our understanding of behaviour and methods of safe designs. The proposed research addresses a crucial issue of the analysis and design of modern structural concrete with innovative solutions for reinforcements. ******Specifically in this proposed work, two types of concrete members are investigated: flat slabs supported on columns, and members reinforced fully or partially using fibre reinforced plastic (FRP) reinforcements. Concrete slabs are not new, but the issue of punching shear still has many unresolved design questions. FRP reinforced members behave according to different principles than traditional steel reinforced members; they rely on concrete to provide post peak ductility. Consequently, discrepancies exist in the design approaches among different codes and design guidelines for both types of these structures. ******Flat concrete slabs on columns and their punching shear behaviour in both static and seismic load scenarios will be studied. Punching shear failures are brittle and dangerous and can lead to progressive collapses of buildings. Testing will be done on prestressed slabs with different shear reinforcing solutions. A hybrid FRP and fibre reinforced concrete (FRC) flat slabs will be tested for their applicability as corrosion resistance systems for Ontario structures and bridges. The damaged plasticity finite element (FE) model within the FE software Abaqus will be used for parametric studies on the effects of concrete and reinforcement properties, placement, slab continuity, openings, unbalanced moments, and support geometry on the punching shear strength. Different codes of practice approach the shear design of slabs differently; all with empirical formulas. A new fib group WP 4.3.2 has been formed to provide guidelines for code developments and to promote a rational mechanics-based approach to punching shear design in slabs (the applicant is an invited member). *******Research on FRP reinforcements in concrete will concentrate on the quality of the reinforcements and of the members reinforced with them. Due to corrosion problems in Ontario, FRP reinforcements are now often considered (e.g., MTO) as a replacement for steel; yet their long-term properties and designs are not fully understood and developed. Work will involve nonlinear FEA studies, strut-and tie modelling, and experimental programs with members reinforced with FRP bars for both flexure and shear. The effects of rebar placement, shear-reinforcement shapes, concrete, and beam geometry will be addressed. The possibility of utilizing fibre reinforced concretes (FRC) with FRP reinforcements will also be investigated both experimentally and numerically. ******All of the above research steps are very fitting for the training of much needed HQP in Canada for both industry and academia. *****