Performance of One-Way Reinforced Concrete Slabs with Externally Bonded Fiber-Reinforced Polymer Strengthening

2004 ◽  
Vol 101 (2) ◽  
Keyword(s):  
Reinforced Concrete ◽  
Fiber Reinforced Polymer ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Externally Bonded

scholarly journals NGHIÊN CỨU THIẾT KẾ TĂNG CƯỜNG KHẢ NĂNG CHỊU UỐN SÀN BÊ TÔNG CỐT THÉP BẰNG VẬT LIỆU TẤM SỢI FRP DÁN NGOÀI

2021 ◽  
Vol 5 (1) ◽  
pp. 2330-2341
Author(s):  
Nguyễn Thị Thanh ◽  
Phạm Việt Hùng ◽  
Ngô Quý Tuấn ◽  
Lê Minh Đức ◽  
Nguyễn Trường Giang
Keyword(s):  
Compressive Strength ◽  
Reinforced Concrete ◽  
Concrete Strength ◽  
Fiber Reinforced Polymer ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Flexural Strengthening ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Calculation Results

Phương pháp tăng cường khả năng chịu uốn của kết cấu sàn bê tông cốt thép sử dụng vật liệu tấm sợi FRP (Fiber Reinforced Polymer) dán ngoài đã trở nên phổ biến, vì những ưu điểm của chúng mang lại như cường độ chịu kéo cao, trọng lượng nhẹ, cách điện, cách nhiệt tốt, bền theo thời gian. Bài báo trình bày quy trình thiết kế tăng cường khả năng chịu uốn của sàn bê tông cốt thép gia cường bằng tấm sợi FRP dán ngoài để đảm bảo yêu cầu khai thác và khảo sát hiệu quả tăng cường tương ứng với các cấp cường độ chịu nén của bê tông theo hướng dẫn ACI 440.2R-17. Kết quả tính toán theo trình tự đề nghị giúp chọn và kiểm tra được diện tích tấm FRP tăng cường cần thiết. Ngoài ra, kết quả tính toán chỉ ra rằng mức độ tăng cường khả năng chịu uốn của sàn tỷ lệ thuận với cường độ chịu nén của bê tông, tương ứng với cường độ bê tông tăng từ 11,5 MPa đến 19,5 MPa, sức kháng uốn tính toán tăng từ 91%  đến 144%. Đồng thời, kết quả cũng cho thấy rằng sự phá hoại của sàn bê tông cốt thép xảy ra do mất dính bám giữa lớp FRP gia cường khỏi bề mặt cấu kiện là chủ yếu. ABSTRACT The method of the flexural strengthening of reinforced concrete slabs using the externally bonded FRP (fiber reinforced polymer) laminates has become popular because of their advantages as high tensile strength, large modulus of elasticity, lightweight, high abrasion resistance, electrical insulation, good heat resistance and durable over the time. The paper presented the design procedure for the flexural strengthening of reinforced concrete slabs with FRP laminates to ensure the mining requirements and investigation of the reinforcement efficiency corresponding to the compressive strength levels of concrete based on ACI 440.2R-17. Calculation results in the suggested sequence helped select and check the required reinforcement FRP areas. In addition, the calculation results showed that the degree of increased flexural strengthening of the slabs was proportional to the compressive strength of the concrete, corresponding to the concrete strength increased from 11,5 MPa to 19,5 MPa, flexural strengthening increases from 91% to 144%. Moreover, the damage to the reinforced concrete slabs was caused by the debonding between the FRP and the surface of the structures.

Thermal effect on fiber reinforced polymer reinforced concrete slabs

2008 ◽  
Vol 35 (3) ◽  
pp. 312-320 ◽  
Author(s):  
A. Zaidi ◽  
R. Masmoudi
Keyword(s):  
Thermal Effect ◽  
Concrete Cover ◽  
Fiber Reinforced Polymer ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer ◽  
Frp Bar ◽  
Frp Bars ◽  
Concrete Interface

The difference between the transverse coefficients of thermal expansion of fiber reinforced polymer (FRP) bars and concrete generates radial pressure at the FRP bar – concrete interface, which induces tensile stresses within the concrete under temperature increase and, eventually, failure of the concrete cover if the confining action of concrete is insufficient. This paper presents the results of an experimental study to investigate the thermal effect on the behaviour of FRP bars and concrete cover, using concrete slab specimens reinforced with glass FRP bars and subjected to thermal loading from –30 to +80 °C. The experimental results show that failure of concrete cover was produced at temperatures varying between +50 and +60 °C for slabs having a ratio of concrete cover thickness to FRP bar diameter (c/db) less than or equal to 1.4. A ratio of c/db greater than or equal to 1.6 seems to be sufficient to avoid splitting failure of concrete cover for concrete slabs subjected to high temperatures up to +80 °C. Also, the first cracks appear in concrete at the FRP bar – concrete interface at temperatures around +40 °C. Comparison between experimental and analytical results in terms of thermal loads and thermal strains is presented.

scholarly journals Modeling Punching Shear Capacity of Fiber-Reinforced Polymer Concrete Slabs: A Comparative Study of Instance-Based and Neural Network Learning

2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Nhat-Duc Hoang ◽  
Duy-Thang Vu ◽  
Xuan-Linh Tran ◽  
Van-Duc Tran
Keyword(s):  
Neural Network ◽  
Regression Model ◽  
Shear Capacity ◽  
Fiber Reinforced Polymer ◽  
Punching Shear ◽  
Polymer Concrete ◽  
Concrete Slabs ◽  
Fiber Reinforced ◽  
Reinforced Concrete Slabs ◽  
Reinforced Polymer

This study investigates an adaptive-weighted instanced-based learning, for the prediction of the ultimate punching shear capacity (UPSC) of fiber-reinforced polymer- (FRP-) reinforced slabs. The concept of the new method is to employ the Differential Evolution to construct an adaptive instance-based regression model. The performance of the proposed model is compared to those of Artificial Neural Network (ANN) and traditional formula-based methods. A dataset which contains the testing results of FRP-reinforced concrete slabs has been collected to establish and verify new approach. This study shows that the investigated instance-based regression model is capable of delivering the prediction result which is far more accurate than traditional formulas and very competitive with the black-box approach of ANN. Furthermore, the proposed adaptive-weighted instanced-based learning provides a means for quantifying the relevancy of each factor used for the prediction of UPSC of FRP-reinforced slabs.

Externally bonded carbon fiber–reinforced polymer composites for seismic retrofit of reinforced concrete coupling beams designed according to old codes

2018 ◽  
Vol 22 (6) ◽  
pp. 1412-1425 ◽  
Author(s):  
Sara Honarparast ◽  
Georges El-Saikaly ◽  
Omar Chaallal
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Polymer Composites ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Reinforced Polymer ◽  
Fiber Reinforced Polymer Composites ◽  
Externally Bonded ◽  
Carbon Fiber Reinforced

A large number of existing buildings have seismic-resistant systems designed according to old code provisions. These structural systems exhibit non-ductile behavior and can present a significant risk in the case of a moderate or significant seismic event. Reinforced concrete–coupled shear walls designed to old codes and standards are among those deficient structures that need to be seismically upgraded. This article aims to investigate a new retrofitting and upgrading method using externally bonded carbon fiber–reinforced polymer composites for existing or/and damaged reinforced concrete coupling beams that can improve the seismic performance of them during earthquakes. To this end, an experimental test was conducted to evaluate the seismic behavior of two identical reinforced concrete–coupled shear wall specimens under reverse cyclic loading. To simulate the old existing building, the specimens were designed and constructed according to the old 1941 National Building Code of Canada with a conventionally reinforced coupling beam. One of the specimens was tested as a control, and the other was strengthened using externally bonded carbon fiber–reinforced polymer composites to evaluate the improvement in its seismic performance. Results show that the retrofit using externally bonded carbon fiber–reinforced polymer resulted in significant enhancement in strength and energy dissipation capacity compared to the conventionally reinforced coupling beam from the control specimen. In addition, externally bonded carbon fiber–reinforced polymer sheets resulted in much improved hysteretic and ductile behavior and in lesser strength and stiffness degradation.

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