Author: Ramin ZargariPublisher:
ISBN:
Category :
Languages : en
Pages : 122
Book Description
Experimental Study of the Behavior of Fiberous Reinforced Concrete Joints Under Cyclic Loads
Author: Ramin ZargariBehavior of Fiber Reinforced Concrete Connections for Precast Frames Under Reversed Cyclic Loading
Author: Rosa Maria VasconezFiber Reinforced Concrete Under Cyclic and Dynamic Compressive Loadings
Author: Duane Eric OtterPublisher:
ISBN:
Category : Composite materials
Languages : en
Pages : 382
Book Description
Ductility of Steel Fiber Reinforced Concrete Connections Under Cyclic Loading
Author: Masoud MajdCyclic Loading Behavior of CFRP-Wrapped Non-Ductile Reinforced Concrete Beam-Column Joints
Author: Publisher:
ISBN:
Category : Carbon fiber-reinforced plastics
Languages : en
Pages : 189
Book Description
Use of fiber reinforced polymer (FRP) material has been a good solution for many problems in many fields. FRP is available in different types (carbon and glass) and shapes (sheets, rods, and laminates). Civil engineers have used this material to overcome the weakness of concrete members that may have been caused by substandard design or due to changes in the load distribution or to correct the weakness of concrete structures over time specially those subjected to hostile weather conditions. The attachment of FRP material to concrete surfaces to promote the function of the concrete members within the frame system is called Externally Bonded Fiber Reinforced Polymer Systems. Another common way to use the FRP is called Near Surface Mounted (NSM) whereby the material is inserted into the concrete members through grooves within the concrete cover. Concrete beam-column joints designed and constructed before 1970s were characterized by weak column-strong beam. Lack of transverse reinforcement within the joint reign, hence lack of ductility in the joints, and weak concrete could be one of the main reasons that many concrete buildings failed during earthquakes around the world. A technique was used in the present work to compensate for the lack of transverse reinforcement in the beam-column joint by using the carbon fiber reinforced polymer (CFRP) sheets as an Externally Bonded Fiber Reinforced Polymer System in order to retrofit the joint region, and to transfer the failure to the concrete beams. Six specimens in one third scale were designed, constructed, and tested. The proposed retrofitting technique proved to be very effective in improving the behavior of non-ductile beam-column joints, and to change the final mode of failure. The comparison between beam-column joints before and after retrofitting is presented in this study as exhibited by load versus deflection, load versus CFRP strain, energy dissipation, and ductility.
FIBER REINFORCED CONCRETE JOINTS FOR PRECAST CONSTRUCTION IN SEISMIC AREAS.
Author: Khaled S. SoubraPublisher:
ISBN:
Category : Fiber-reinforced concrete
Languages : en
Pages : 664
Book Description
demands for the precast frame.
Behavior of Fiber Reinforced Concrete Connections for Precast Frames Under Reversed Cyclic Loading
Author: Rosa M. VasconezPublisher:
ISBN:
Category : Concrete construction
Languages : en
Pages : 302
Book Description
Bond Behavior of Advanced Fiber Reinforced Composite-concrete Joints
Author: Xingxing ZhouPublisher:
ISBN:
Category :
Languages : en
Pages : 206
Book Description
"Externally bonding advanced composite materials to concrete structures is an effective way to improve their strength, ductility, and durability. The interfacial bond behavior is fundamental to understand the overall structural performance of concrete structures strengthened with advanced composite materials. This study includes a comprehensive investigation of the bond behavior of composite-concrete joints with different fiber reinforced composite types. First, a direct approach to determine the bond-slip relationship for fiber reinforced cementitious matrix (FRCM)-concrete joints based on fiber strain measurements was proposed. Then, an analytical solution to predict the full-range response of FRCM-concrete joints was derived by assuming a trilinear bond-slip relationship. The analytical results were compared with experimental load responses to indirectly determine the bond-slip relationship. Next, the experimental load response of steel fiber reinforced polymer (SRP)-concrete joints was explored by single-lap direct shear tests. Lastly, a novel non-destructive evaluation method - active microwave thermography - was used to detect the existence of initial interfacial defects in carbon fiber reinforced polymer (CFRP)-concrete joints, and to monitor the progressive debonding between CFRP and concrete"--Abstract, page iv.
Structural Behavior of Rubberized Concrete Containing Synthetic Fibers
Author: Basem Hassan Abdelbaset AbdelaleemPublisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
This research program aims to investigate the combining effect of crumb rubber (CR) and synthetic/metal fibers (SFs/MFs) in the development of concrete suitable for structural applications subjected to monotonic and cyclic loading. The research also aims to overcome the challenge of optimizing the strength and stability of self-consolidating concrete (SCC) containing CR and SFs/MFs. Five comprehensive experimental studies were conducted on both small-scale and large-scale concrete samples to meet the research objectives. The first study aimed to develop and optimize a number of successful self-consolidating rubberized concrete (SCRC) and synthetic fiber SCRC (SFSCRC) mixtures with a maximized percentage of CR and minimized reduction in strength. The variables in this study included various supplementary cementing materials (SCMs) specifically metakaolin (MK), silica fume (SLF), fly ash (FA), and ground granulated blast-furnace slag (GGBS), different binder contents (500, 550, and 600 kg/m3), varying percentages of CR (0% to 30%), different types of SFs specifically micro-synthetic fibers (MISFs), and macro-synthetic fibers (MASFs), different lengths of SFs (19mm, 27mm, 38mm, 50mm, and 54mm), and different SFs volume fractions (0%, 0.2%, and 1%). The second and third studies evaluated the flexural and shear behavior of large-scale reinforced concrete beams made with SCRC, vibrated rubberized concrete (VRC), SFSCRC, and synthetic fiber VRC (SFVRC). The fourth study investigated the structural performance of rubberized beam-column joints reinforced with SFs/MFs under reverse cyclic loading. This study consisted of three stages: the first stage contained a total of six SCRC mixtures selected to cast six beam-column joints with varied percentages of CR (0-25%). The second stage included eight rubberized concrete mixtures with different coarse aggregate sizes and different MFs lengths and volumes selected to pour eight beam-column joints to be tested under cyclic loading. The third stage contained seven rubberized concrete beam-column joints reinforced with different types, lengths, and volumes of SFs to be tested under cyclic loading. The fifth study evaluated the cyclic behavior of engineering cementitious composite (ECC) beam-column joints made with different percentages of CR, different SCMs, and different sand types. In this study a total of eight beam-column joints were cast and tested under reverse cyclic loading. The main results drawn from the first study indicated that the addition of SFs reduced the fresh properties, which limited the maximum percentage of CR that could be used in SCRC mixtures to 20%, compared to a 30% maximum percentage of CR used in developing successful SCRC mixtures without SFs. However, using SFs in SCRC mixtures increased the impact resistance and appeared to alleviate the reduction in splitting tensile strength (STS) and flexural strength (FS) that resulted from adding CR. The main results of the flexural testing conducted in study 2 indicated that using MISFs slightly enhanced the deformability, flexural stiffness, ductility, energy absorption, first cracking moment, and bending moment capacity, while this enhancement significantly increased when MASFs were used. Combining high percentage of MASFs (1%) with high percentage of CR (30%) compensated for the reduction in the bending moment capacity that resulted from using high percentage of CR, and helped to develop semi-lightweight concrete beams. The inclusion of CR in study 3 negatively affected the ultimate shear load, post-diagonal cracking resistance, and first cracking moment of the tested beams while it improved the deformation capacity, self-weight, and cracking pattern. Combining CR with MISFs or MASFs, further improved the deformation capacity, self-weight, and narrowed the crack widths of the tested beams. The results of this study also indicated that the use of a relatively higher percentage of fibers (1% compared to 0.2%) in VRC beams significantly compensated for the reduction in shear strength resulting from a high CR percentage (30%). The results of the fourth study revealed that the optimum percentage of CR to be used in beam-column joint mixtures is 15%. Although using this percentage slightly reduced the load carrying capacity, it greatly enhanced the ductility, brittleness index, deformability, and energy dissipation. The results also revealed that using MISFs slightly improved the structural performance of beam-column joints, while using MASFs had a significant effect on enhancing the load carrying capacity, ductility, stiffness, and energy dissipation of tested joints. The main results of the fifth study reported that increasing the percentage of CR up to 15% significantly increased the deformability, cracking behavior, ductility, and energy dissipation of ECC joints, while the initial stiffness, first crack load, and ultimate load were decreased.
Author: Ghassan Wadih Kaddi