Improving the seismic behaviour of reinforced concrete moment resisting frames by means of SMA bars and ultra-high performance concrete

2019 ◽  
Vol 197 ◽  
pp. 109409 ◽  
Author(s):  
A. Navarro-Gómez ◽  
José L. Bonet
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Ultra High Performance Concrete ◽  
Seismic Behaviour ◽  
Moment Resisting Frames ◽  
Moment Resisting

scholarly journals Embedded carbon fiber-reinforced polymer rod in reinforced concrete frame and ultra-high-performance concrete frame joints

2019 ◽  
Vol 11 (S1) ◽  
pp. 35-51
Author(s):  
Shahnaz Basim ◽  
Farzad Hejazi ◽  
Raizal Saifulnaz Bin Muhammad Rashid
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
High Performance ◽  
High Performance Concrete ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Ultra High Performance Concrete ◽  
Concrete Frame ◽  
Reinforced Polymer

AbstractBeam–column joints play an important role in providing lateral stiffness and integrity of frames during dynamic loading such as earthquake. In the high humidity areas, during functioning of the building cracks occur, which leads to the corrosion of the reinforcement due to the environmental exposures. Therefore, one of the main failures mechanism of building during an earthquake is caused by easily yielding of corroded steel reinforcement, which leads to reduce functionality of the frame joints in transferring the loads. This study proposed a new design to reinforce the beam-column joints with embedded carbon fiber-reinforced polymer (CFRP) rods, due to their extremely high strength and stiffness, along with the fact that they will not rust or corrode and very light weight. CFRP rods are used in reinforced concrete (RC) frame and ultra-high-performance concrete (UHPC) frame subjected to dynamic load. The prototype of the proposed design is constructed as frame with conventional concrete and frame with UHPC material to conduct experiments Test as well as numerical analysis to evaluate the performance of the proposed joints under dynamic loads. The results showed improvement in the performance of the frames reinforced with embedded CFRP in joints in terms of lateral load resistance capacity, ductility behaviour, overall stiffness, and failure mechanism.

scholarly journals Influence of Cracking on Oxygen Transport in UHPFRC Using Stainless Steel Sensors

2019 ◽  
Vol 10 (1) ◽  
pp. 239
Author(s):  
Ana Martínez-Ibernón ◽  
Marta Roig-Flores ◽  
Josep Lliso-Ferrando ◽  
Eduardo J. Mezquida-Alcaraz ◽  
Manuel Valcuende ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Oxygen Availability ◽  
Fiber Reinforced Concrete ◽  
Reinforced Concrete Beams ◽  
Fiber Reinforced ◽  
Ultra High Performance Concrete ◽  
Cracking Behavior

Reinforced concrete elements frequently suffer small cracks that are not relevant from the mechanical point of view, but they can be an entrance point for aggressive agents, such as oxygen, which could initiate the degradation processes. Fiber-Reinforced Concrete and especially Ultra High Performance Concrete increase the multi-cracking behavior, reducing the crack width and spacing. In this work, the oxygen availability of three types of concrete was compared at similar strain levels to evaluate the benefit of multi-cracking in the transport of oxygen. The types of concrete studied include traditional, High-Performance, and Ultra-High-Performance Fiber-Reinforced Concrete with and without nanofibers. To this purpose, reinforced concrete beams sized 150 × 100 × 750 mm3 were prepared with embedded stainless steel sensors that were located at three heights, which have also been validated through this work. These beams were pre-cracked in bending up to fixed strain levels. The results indicate that the sensors used were able to detect oxygen availability due to the presence of cracks and the detected differences between the studied concretes. Ultra High Performance Concrete in the cracked state displayed lower oxygen availability than the uncracked High Performance Concrete, demonstrating its potential higher durability, even when working in cracked state, thanks to the increased multi-cracking response.

scholarly journals Probabilistic fatigue analysis of ultra-high-performance fibre-reinforced concrete under thermal effects

2018 ◽  
Vol 165 ◽  
pp. 12001
Author(s):  
José D. Ríos ◽  
Héctor Cifuentes
Keyword(s):  
Reinforced Concrete ◽  
Thermal Effects ◽  
High Performance ◽  
High Performance Concrete ◽  
Fatigue Behaviour ◽  
Fibre Reinforcement ◽  
Fibre Reinforced Concrete ◽  
Ultra High Performance Concrete ◽  
Polypropylene Fibres ◽  
High Performance Fibre

This paper describes the influence of the temperature and the fibre reinforcement on the flexural fatigue behaviour of an ultra-high-performance fibre-reinforced concrete. Three-point bending fatigue tests were carried out for an ultra-high-performance concrete subjected to different temperatures ranging from room temperature up to 300 ºC and considering three different types of reinforcement: a) steel fibres, b) hybrid steel and polypropylene fibres and c) non-reinforced (reference matrix). The fatigue behaviour was assessed from the S-N fields obtained through a probabilistic fatigue model developed by Castillo and Fernández-Canteli. The influence of the type of reinforcement on the fatigue behaviour was analysed by SN curves. An analysis of the thermal effects in the fatigue life of the ultra-high-performance concrete has also been carried out. The results showed the most suitable fibre reinforcement among the analysed options to get the best fatigue behaviour in accordance to the exposure temperature.

scholarly journals Ultra high Performance Concrete - Materials Formulations and Serviceability based Design

2018 ◽  
Author(s):  
Barzin Mobasher ◽  
Yiming Yao ◽  
Aashay Arora ◽  
Narayanan Neithalath
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
High Performance Concrete ◽  
Cementitious Materials ◽  
Fiber Reinforced Concrete ◽  
Analytical Models ◽  
Tension Stress ◽  
Optimization Approach ◽  
Cement Composites ◽  
Ultra High Performance Concrete

Materials and mechanical design procedures for ultra-high performance cement composites (UHPC) members based on analytical models are addressed. A procedure for the design of blended components of UHPC is proposed using quaternary cementitious materials. The blending procedures are used using a packing and rheology optimization approach to blend high performance mixtures using non-proprietary formulations. Closed-form solutions of moment-curvature responses of UHPC are derived based on elastic-plastic compressive model and trilinear strain hardening tension stress strain responses. Tension stiffening behavior of UHPC due to fiber toughening and distributed cracking is then incorporated in the cross-sectional analysis. Load-deflection responses for beam members are obtained using moment-area, and direct integration approach. The proposed models provide insights in the design of SHCC to utilize the hardening properties after cracking. Using proper parameters, generalized materials model developed are applicable to both SHCC and strain softening cement composites such as steel fiber reinforced concrete (SFRC), textile reinforced concrete (TRC) and ultra-high performance concrete (UHPC).DOI: http://dx.doi.org/10.4995/HAC2018.2018.8263

scholarly journals Advanced composite structure combining Ultra high performance concrete with normal reinforced concrete

2019 ◽  
Vol 278 ◽  
pp. 03004
Author(s):  
Xiangguo Wu
Keyword(s):  
Reinforced Concrete ◽  
Material Properties ◽  
Composite Structure ◽  
Composite Structures ◽  
High Performance ◽  
High Performance Concrete ◽  
Raw Materials ◽  
Constitutive Relations ◽  
Ultra High Performance Concrete ◽  
Advanced Composite

Ultra high performance concrete (UHPC), one of the newest cementitious composites, demonstrates superior ductility with high strength and durability, which has gained the attention of researchers and engineers since it was successfully developed. Considering its superior ductility and durability, UHPC is a good alternative material for forming a advanced composite structure with normal reinforced concrete (RC) or prestressed concrete. The material properties are critical for its application in composite structures, so in this chapter, material properties of UHPC, such as constitute raw materials, mechanical properties, durability and several constitutive relations from several standards are firstly introduced. The basic concepts of advanced UHPC-RC composite structures, such as UHPC-RC composite beam, composite column, composite wall, etc, are introduced finally.

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