scholarly journals Effects of Hybrid Fiber on Flexural Behavior of Green RC Beams in Oman Sea

2021 ◽  
Vol 5 (2) ◽  
pp. 1-10
Author(s):  
Hamed Safayenikoo ◽  
Keyword(s):  
Flexural Behavior ◽  
Rc Beams ◽  
Hybrid Fiber ◽  
Oman Sea

Experimental and analytical investigation of using externally bonded, hybrid, fiber-reinforced polymers to repair and strengthen heated, damaged RC beams in flexure

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Yousef Al Rjoub ◽  
Ala Obaidat ◽  
Ahmed Ashteyat ◽  
Khalid Alshboul
Keyword(s):  
Fiber Reinforced Polymer ◽  
Flexural Behavior ◽  
Fiber Reinforced Polymers ◽  
Rc Beams ◽  
Fiber Reinforced ◽  
Hybrid Fiber ◽  
Reinforced Polymers ◽  
Content Type ◽  
Reinforced Polymer ◽  
Damaged Beams

PurposeThis study aims to conduct an experimental study and finite element model (FEM) to investigate the flexural behavior of heat-damaged beams strengthened/repaired by hybrid fiber-reinforced polymers (HFRP).Design/methodology/approachTwo groups of beams of (150 × 250 × 1,200) mm were cast, strengthened and repaired using different configurations of HFRP and tested under four-point loadings. The first group was kept at room temperature, while the second group was exposed to a temperature of 400°C.FindingsIt was found that using multiple layers of carbon fiber-reinforced polymer (CFRP) and glass fiber-reinforced polymer (GFRP) enhanced the strength more than a single layer. Also, the order of two layers of FRP showed no effect on flexural behavior of beams. Using a three-layer scheme (attaching the GFRP first and followed by two layers of CFRP) exhibited increase in ultimate load more than the scheme attached by CFRP first. Furthermore, the scheme HGC (heated beam repaired with glass and carbon, in sequence) allowed to achieve residual flexural capacity of specimen exposed to 400°C. Typical flexural failure was observed in control and heat-damaged beams, whereas the strengthened/repaired beams failed by cover separation and FRP debonding, however, specimen repaired with two layers of GFRP failed by FRP rupture. The FEM results showed good agreement with experimental results.Originality/valueFew researchers have studied the effects of HFRP on strengthening and repair of heated, damaged reinforced concrete (RC) beams. This paper investigates, both experimentally and analytically, the performance of externally strengthened and repaired RC beams, in flexure, with different FRP configurations of CFRP and GFRP.

Susceptibility of strain-hardening cementitious composite to curing conditions as a retrofitting material for RC beams

2021 ◽  
Vol 16 ◽  
pp. 155892502110203
Author(s):  
Mohammad Iqbal Khan ◽  
Galal Fares ◽  
Yassir Mohammed Abbas ◽  
Wasim Abbass ◽  
Sardar Umer Sial
Keyword(s):  
Strain Hardening ◽  
Environmental Conditions ◽  
Carrying Capacity ◽  
Flexural Behavior ◽  
Load Carrying Capacity ◽  
Rc Beams ◽  
Curing Conditions ◽  
Flexural Members ◽  
Load Carrying ◽  
Curing Regime

Strain-hardening cement-based composites (SHCC) have recently been developed as repair materials for the improvement of crack control and strength of flexural members. This work focuses on strengthening and flexural enhancement using SHCC layer in tensile regions of flexural members under three different curing conditions. The curing conditions simulate the effect of different environmental conditions prevailing in the central and coastal regions of the Arabian Peninsula on the properties of SHCC as a retrofitting material. In this investigation, beams with SHCC layer were compared to control beams. The beams with SHCC layer of 50-mm thickness were cast. The results revealed that the flexural behavior and the load-carrying capacity of the normal concrete beam specimens under hot and dry environmental conditions were significantly reduced, lowering the ductility of the section. However, compressive strength is comparatively unaffected. Similarly, the hot curing conditions have also led to a notable reduction in the loading capacity of the beam with SHCC layer with a slight effect on its stiffness. On the other hand, steam-curing conditions have shown improvement in load-carrying capacity and a reduction in section ductility of the beam with SHCC layer. It was found that the structural unit retrofitted with SHCC layer was a curing-regime dependent as the tensile and strain-hardening properties of SHCC are highly sensitive to the alteration in the cement hydration process. A normal curing regime was found effective and satisfying the practical, cost, and performance requirements. Accordingly, a normal curing regime could be implemented to retrofit reinforced concrete (RC) beams with SHCC layers as recommended in the study.

Experimental study on the flexural behavior of RC beams strengthened with prestressed BFRP laminates

2021 ◽  
Vol 233 ◽  
pp. 111801
Author(s):  
Changyuan Liu ◽  
Xin Wang ◽  
Jianzhe Shi ◽  
Lulu Liu ◽  
Zhishen Wu
Keyword(s):  
Experimental Study ◽  
Flexural Behavior ◽  
Rc Beams

Flexural Fatigue Performance of RC Beams Strengthened with Hybrid Fiber Sheets

2012 ◽  
Vol 166-169 ◽  
pp. 1657-1662
Author(s):  
Xu Jun Chen ◽  
Xiao E Zhu ◽  
Zhong Yang ◽  
Mu Xiang Dai
Keyword(s):  
Fatigue Life ◽  
Basalt Fiber ◽  
Reinforced Concrete Beams ◽  
Fatigue Performance ◽  
Rc Beam ◽  
Rc Beams ◽  
Hybrid Fiber ◽  
Cycle Number ◽  
Flexural Fatigue ◽  
Variation Characteristics

Based on the fatigue test for flexural performance of five reinforced concrete beams, the variation characteristics of the crack development, concrete strain, steel strain, fiber strain with the cycle number of the fatigue load were analyzed, and the effect of hybrid fiber sheets and basalt fiber reinforced polymer(BFRP)sheets on flexural fatigue performance of the strengthened beam was studied. The results show that the accumulated damage of RC beams strengthened with hybrid fiber sheets was slowed down significantly, the anti-crack property was much improved, and the fatigue life was greatly prolonged. Compared with the ordinary RC beam and the RC beam strengthened with double BFRP sheets, the fatigue life of RC beams strengthened with hybrid CFRP/BFRP(C/BFRP) sheets and hybrid CFRP/GFRP(C/GFRP) sheets was increased by 291.26%, 298.63% and 10.73%, 13.53%.

scholarly journals Effect of different PVA and steel fiber length and content on mechanical properties of CaCO3 whisker reinforced cementitious composites

2019 ◽  
Vol 69 (336) ◽  
pp. 200 ◽  
Author(s):  
M. Cao ◽  
C. Xie ◽  
L. Li ◽  
M. Khan
Keyword(s):  
Mechanical Properties ◽  
Crack Resistance ◽  
Fiber Length ◽  
Large Deflection ◽  
Steel Fiber ◽  
Flexural Behavior ◽  
Cementitious Composites ◽  
Hybrid Fiber ◽  
Pva Fiber ◽  
Fiber Reinforced Cementitious Composites

In this paper, calcium carbonate (CaCO3) whisker as a fiber reinforcement is mixed with steel and PVA fiber to form a multiscale hybrid fiber reinforced cementitious composites (MHFRCC). ASTM standard and post-crack strength techniques are performed to evaluate the mechanical properties of MHFRCC. The 1.25 % long steel fiber, 0.55 % short PVA fiber and 2.0 % CaCO3 whisker specimens showed the best flexural behavior before L/600 deflection. However, 1.5 % long steel fiber, 0.4 % long PVA fiber and 1.0 % CaCO3 whisker specimens presented better crack resistance after L/600 deflection. It is revealed that flexural parameters increase as comprehensive reinforcing index increase. The result showed that the CaCO3 whisker and short PVA fiber provided crack resistance effect at micro-scale and mainly play a dominate role in inhibiting micro-cracking. However, long steel fiber and long PVA fiber showed a better bridging effect of macro cracks at a large deflection.

scholarly journals Effect of loading rate on flexural behavior of concrete and reinforced concrete beams

2021 ◽  
Vol 15 (3) ◽  
pp. 136-143
Author(s):  
Nguyen Trung Hieu ◽  
Nguyen Van Tuan
Keyword(s):  
Reinforced Concrete ◽  
Loading Rate ◽  
Plain Concrete ◽  
Reinforced Concrete Beams ◽  
Flexural Behavior ◽  
Displacement Curve ◽  
Rc Beams ◽  
Three Point Bending ◽  
Loading Rates ◽  
Hydraulic Servo

The elasto-plastic characteristics of plain concrete are inevitably affected by the loading rate. This paper presents an experimental investigation on the effect of loading rate on flexural behavior of concrete and reinforced concrete (RC) beams, which was carried out with Walter+bai electro-hydraulic servo system. Three-point bending tests on 100 × 100 × 400 mm prismatic concrete samples and 80 × 120 × 1100 mm RC beams with different displacement controlled loading rates of 0.01 mm/min, 0.1 mm/min, and 3 mm/min were imposed. Based on the test results, the effects of loading rates on the load-displacement curve, cracking, and ultimate load-carrying capacities of RC beams were evaluated.

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