A NUMERICAL STUDY ON THE MITIGATION EFFECTS BY ARAMID FIBER SHEET REINFORCEMENT ON THE SCABBING OF RC SLABS

2020 ◽  
Vol 76 (2) ◽  
pp. I_347-I_358
Author(s):  
Shogo KIYOTA ◽  
Masuhiro BEPPU ◽  
Hiroyoshi ICHINO ◽  
Kazuyuki SATO
Keyword(s):  
Numerical Study ◽  
Aramid Fiber ◽  
Fiber Sheet ◽  
Rc Slabs

Experimental and Numerical Study of Basalt FRP Strip Strengthened RC Slabs under Impact Loads

2020 ◽  
Vol 20 (06) ◽  
pp. 2040001 ◽  
Author(s):  
Wensu Chen ◽  
Thong M. Pham ◽  
Mohamed Elchalakani ◽  
Huawei Li ◽  
Hong Hao ◽  
...  
Keyword(s):  
Failure Modes ◽  
Shear Failure ◽  
Numerical Study ◽  
Impact Resistance ◽  
Basalt Fiber ◽  
Impact Behavior ◽  
Impact Loads ◽  
Quantitative Measurements ◽  
Rc Slabs ◽  
The Impact

Basalt fiber-reinforced polymer (BFRP) has been applied for strengthening concrete structures. However, studies on reinforced concrete (RC) slabs strengthened by BFRP strips under impact loads are limited in open literature. This study investigates the efficiency of using BFRP strips with various strengthening layouts and anchoring schemes on the impact resistance of RC slabs. A total of 11 two-way square slabs were prepared and tested, including one reference specimen without strengthening and ten slabs strengthened with BFRP strips and/or anchors. The RC slabs were impacted by a drop weight with increasing height until slab failure. The observed failure modes include punching shear failure, BFRP sheet debonding and reinforcement fracture. The failure modes and the effects of using various strengthening schemes on the impact resistant capacity of RC slabs were examined. The quantitative measurements, such as impact velocity, indentation depth and diameter, were compared and discussed. In addition, numerical studies were carried out by using LS-DYNA to simulate the impact tests of RC slabs with and without BFRP strengthening. With the calibrated numerical model, the impact behavior of slabs with various dimensions and strengthening layouts under different impact intensities can be predicted with good accuracy.

Experimental and numerical study of the behavior of RC slabs with openings reinforced by metal mesh under impact loading

2018 ◽  
Vol 9 (2) ◽  
pp. 37
Author(s):  
Yousry B. I. Shaheen ◽  
Ghada Mousa Hekal ◽  
Ahmed Khaled Fadel
Keyword(s):  
Impact Loading ◽  
Impact Load ◽  
Numerical Study ◽  
Fe Model ◽  
Test Results ◽  
Metal Mesh ◽  
Expanded Metal ◽  
Rc Slabs

The main objective of the following work is to inspect the effect of reinforcing metal mesh on the behavior of slabs with openings under impact loadings. Based on an earlier numerical study by Shaheen et al. (2017), slabs with mid-side openings revealed the worst behavior regarding to deflection and cracked pattern when subjected to impact loading compared to other slabs with different locations of openings. Hence, the present work focuses specifically on this type of slabs and the variation in their behavior when reinforced by welded or expanded metal mesh. Seven specimens were prepared and tested in Faculty of Engineering, Menoufia University, Egypt. Moreover, a FE model for the slabs was built using Abaqus 6.14 and verified against test results. It was found that expanded metal mesh had a significant effect on reducing deflection due to impact load as well as controlling of cracks in contrast with welded metal mesh.

A Numerical Study and Material Test for Damping Factor of Carbon-Aramid Fiber Reinforced Plastics Robot Arm

2015 ◽  
Vol 52 (6) ◽  
pp. 444-450
Author(s):  
Dong-Woo Shin ◽  
Il-Jun Kwon ◽  
Sung-Min Park ◽  
Yong-Min Park ◽  
Jin-Kyung Choi
Keyword(s):  
Numerical Study ◽  
Aramid Fiber ◽  
Damping Factor ◽  
Robot Arm ◽  
Fiber Reinforced ◽  
Material Test ◽  
Reinforced Plastics ◽  
Fiber Reinforced Plastics

Mechanical Performance of Beams Strengthened by Carbon Fiber Sheet Bonded with Inorganic Adhesive after Fire

2012 ◽  
Vol 256-259 ◽  
pp. 873-877
Author(s):  
Fu Xiong Wan ◽  
Wen Zhong Zheng
Keyword(s):  
Carbon Fiber ◽  
Mechanical Performance ◽  
Fire Behavior ◽  
Softening Temperature ◽  
Epoxy Adhesive ◽  
Reinforced Concrete Beams ◽  
Epoxy Adhesives ◽  
Fiber Sheet ◽  
Rc Slabs ◽  
Carbon Fiber Sheet

According to the fact that softening temperature of organic epoxy adhesive is too low to meet fire, an inorganic adhesive whose strength at 600°C is not lower than that at normal room temperature, is developed to bond Carbon Fiber Sheet (CFS) in order to strengthen reinforced concrete beams. To understand all-round mechanical performance of RC beams strengthened by CFS bonded by an inorganic adhesive after fire, on the base of experimental research, Conjugate Beam Method is used to analyze the whole mechanical process from loading to failure. The test and analysis results show that, for RC slabs strengthened by CFS bonding with the inorganic adhesive, maximum stress of CFS decreases with small amplitude compared with that before fire, and the strength of the sheet can be utilized to a great extent, even if temperature (about 300°C~470°C) an inorganic adhesive experienced outclasses softening temperatures of ordinary organic epoxy adhesives. Beams strengthened by CFS bonded with inorganic adhesive perform good fire behavior.

scholarly journals Evaluation of Sustainable Structural Concrete Using Recycled Aggregate and Aramid Fiber Sheet

2016 ◽  
Vol 2016 ◽  
pp. 1-9
Author(s):  
Y. S. Cho ◽  
H. S. Jang ◽  
S. K. Back ◽  
M. I. Choi ◽  
S. U. Hong ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Concrete Beam ◽  
Promising Result ◽  
Ductile Failure ◽  
Aramid Fiber ◽  
Recycled Aggregate Concrete ◽  
Experimental Results ◽  
Recycled Aggregate ◽  
Flexural Performance ◽  
Fiber Sheet

The purpose of this study was to evaluate the flexural performance of recycled aggregate RC beam reinforced with aramid fiber sheets. Compressive strength of concrete using recycled aggregate is generally similar or slightly lower than normal concrete. To improve the compressive strength, aramid fiber sheets have been used in this study. This study examines the structural behavior of concrete beams prepared with recycled aggregate and strengthened aramid fiber sheets at varying locations. One concrete beam as a control specimen, that is prepared with 30 percent recycled aggregate and 70 percent natural aggregate, has been tested, and 3 more strengthened beams (bottom, bottom and sides, bottom and both ends with U-shaped strengthened beams) are tested. The ultimate loads have increased by 38.01%, 39.88%, and 100.79% for bottom, bottom and sides, bottom and both ends with U-shaped strengthened beams. The ductility ratios are 2.75~6.20 for strengthened beams. The experimental results showed that the strengthening system with U-shaped band controls the premature debonding and provides a more ductile failure mode than the strengthening system without U-shaped bands. It can be found that the ultimate strength of H40-RGA30-BS specimen based on load-deflection curves shows most promising result. The experimental results are compared with the analytical results of nonlinear flexural behaviors for strengthened reinforced recycled aggregate concrete beam.

scholarly journals Behaviour of RC structures strengthened with prestressed CFRP laminates: a numerical study

2019 ◽  
Author(s):  
José Sena-Cruz ◽  
Luís Correia ◽  
Paulo França
Keyword(s):  
Numerical Study ◽  
Shear Stresses ◽  
Premature Failure ◽  
Rc Structures ◽  
Cfrp Laminate ◽  
Flexural Strengthening ◽  
Cfrp Laminates ◽  
Externally Bonded ◽  
Fibre Reinforced Polymer ◽  
Rc Slabs

<p>The externally bonded reinforcement (EBR) technique is one of the most widely used strategies for the flexural strengthening of reinforced concrete (RC) with fibre reinforced polymer (FRP) materials. The EBR technique offers several structural advantages when the FRP material is prestressed. The development of high shear stresses at the ends of the prestressed FRP material can cause premature FRP peeling-off failure. This premature failure can be delayed or even avoided with the use of special end-anchorage systems, like the mechanical anchorage (MA) system and the gradient anchorage (GA) system. This paper presents an experimental and a numerical study on RC slabs strengthened in flexure with prestressed carbon FRP (CFRP) laminate strips, namely: (i) one reference slab; (ii) one slab strengthened with non- prestressed externally bonded CFRP (EB-CFRP) laminate; (iii, iv) and two slabs strengthened with prestressed EB-CFRP laminates using the MA and GA systems. The performance of these simulations was compared with results of the slabs experimentally tested up to failure. Subsequently, these models were used on a parametric study that intended to investigate the influence of different parameters affecting the behaviour of the slabs strengthened with prestressed EB-CFRP laminates.</p>

scholarly journals Deformation Behavior of Reinforced Concrete Two-Way Slabs Strengthened with Different Widths and Configurations of GFRP

2017 ◽  
Vol 3 (11) ◽  
pp. 1121
Author(s):  
Hossein Izadi ◽  
Hamid Pesaran Behbahani
Keyword(s):  
Reinforced Concrete ◽  
Deformation Behavior ◽  
Numerical Study ◽  
Fiber Reinforced Polymer ◽  
Steel Reinforced Concrete ◽  
Reinforced Polymer ◽  
Glass Fiber Reinforced ◽  
Comparison Results ◽  
Rc Slabs ◽  
Strip Length

In this paper, we conducted a numerical analysis of the deformation behavior of Steel-reinforced concrete (RC) two-way slabs strengthened by glass fiber reinforced polymer (GFRP) with different widths and configurations. A total number of 36 RC slabs of  cm were used in this numerical study. Also, a column of  was considered in the center of the slab for applying static loading. The bonded GFRP strips had 5, 7.5 and 10 cm width (W) and configured in three models called PM1, PM2, and DM. In PM1 (strip length = 2.4 m) and PM2 (strip length =1.7 m) configurations, the strips were bonded in two directions parallel to the sides of the slab, while in DM configuration (strip length =1.7 m), strips were rotated with 45 degree angle around the central axis that is perpendicular to the surface of the slab. According to the comparison results, we found out that the 5-cm wide strips with PM1 configuration having a parallel space of 0.5 times the strip width ( ) greatly reduced the deformation of RC two-way slab compared to other strip widths and configurations, while  strips under all configurations, highly increased the deformation when space between strips varied from  to .

Experimental and numerical study on the dynamic response of RC slabs under blast loading

2016 ◽  
Vol 66 ◽  
pp. 120-129 ◽  
Author(s):  
Shujian Yao ◽  
Duo Zhang ◽  
Xuguang Chen ◽  
Fangyun Lu ◽  
Wei Wang
Keyword(s):  
Dynamic Response ◽  
Numerical Study ◽  
Blast Loading ◽  
Rc Slabs

Nonlinear Analysis on Slabs Strengthened by Carbon Fiber Sheet Bonded with Inorganic Adhesive after Fire

2012 ◽  
Vol 256-259 ◽  
pp. 831-835
Author(s):  
Fu Xiong Wan ◽  
Wen Zhong Zheng
Keyword(s):  
Carbon Fiber ◽  
Maximum Stress ◽  
Mechanical Performance ◽  
Fire Behavior ◽  
Iterative Computation ◽  
Epoxy Adhesives ◽  
Fiber Sheet ◽  
Program Load ◽  
Rc Slabs ◽  
Carbon Fiber Sheet

To understand all-round mechanical performance of RC slabs strengthened by Carbon Fiber Sheet (CFS) bonding with the inorganic adhesive after fire, Conjugate Method is used to analyze the whole mechanical process from loading to failure. On the base of plane section assumption, Moment- Curvature curves are obtained by iterative computation program. Load-displacement curves of slabs at mid-span after fire are obtained by Conjugate Method, and furthermore, curve of moment-sheet stress relationship is obtained, stress of CFS is analyzed. The test and analysis results show that, for RC slabs strengthened by CFS bonded with an inorganic adhesive, maximum stress of composite sheet decreases with small amplitude compared with that at room temperature, and the strength of the sheet can be utilized to a great extent, even if temperature (about 200°C~300°C) an inorganic adhesive experienced outclasses softening temperatures of ordinary organic epoxy adhesives. Slabs strengthened by CFS bonded with inorganic adhesive perform good fire behavior.

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