Carbon Fiber Strips Retrofitting System for Precast Reinforced Concrete Wall Panel

2015 ◽  
Vol 660 ◽  
pp. 208-212 ◽  
Author(s):  
Mihai Fofiu ◽  
Andrei Bindean ◽  
Valeriu Stoian
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Maximum Load ◽  
Fiber Reinforced Polymers ◽  
Wall Panel ◽  
Concrete Wall ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Concrete Wall

This paper presents the retrofitting procedure used on a precast reinforced concrete wall panel (PRCWP) in order to restore its initial load bearing capacity. The specimen used in this experimental test is one from the residential multistoried buildings constructed in Romania from the 1970 onwards. All of the characteristics of the element are from the specific era, only scaled down with a factor of 1:1,2. The element was subjected to in-plane reversed cyclic loading to simulate its seismic behavior and obtain its maximum load bearing capacity. After the test we retrofitted the element using Carbon Fiber Strips Externally Bonded (EBR) and anchored with Carbon Fiber Reinforced Polymers (CFRP) mesh. The porpoise of the paper is to compare the maximum loading bearing capacity of the unstrengthen and strengthen elements in order to compare them and examine the efficiency of this retrofitting procedure.

EXPERIMENTAL INVESTIGATION ON STRENGTHENING OF REINFORCED CONCRETE COLUMNS WITH CARBON CONCRETE COMPOSITE

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Klaus Holschemacher ◽  
Dennis Messerer ◽  
Wladislaw Polienko
Keyword(s):  
Reinforced Concrete ◽  
Carbon Fiber ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Concrete Columns ◽  
Experimental Program ◽  
Load Bearing Capacity ◽  
Reinforced Concrete Columns ◽  
Load Bearing ◽  
Concrete Members

The application of textile reinforced concrete is well-approved technique for strengthening of reinforced concrete members. When using carbon fiber meshes and carbon fiber reinforced polymer bars as reinforcement, this material is called carbon concrete composite. Based on the outstanding properties of carbon fibers, carbon concrete composite is characterized by high bending and tensile strength, and good durability. Therefore, carbon concrete composite is increasingly applied as replacement for ordinary steel bar or steel mesh reinforced concrete. It is favorable building material for production of new buildings and for strengthening of existing reinforced concrete members. In the context of strengthening of existing reinforced concrete columns, it is a usual procedure to cover the member’s surface with a thin layer of carbon concrete composite aiming on reduction of lateral strains of the core concrete when load is increasing. The result is an increased load-bearing capacity of the strengthened column. However, there is insufficient knowledge about the influence of curvature of the carbon meshes in circular cross-sections and in the corners of rectangular cross-sections on their load-bearing capacity. For this reason, an experimental program started to study the influence of curvature, number and type of mesh layers and specimen dimensions on structural behavior of strengthened columns under axial loading. As main outcome it can be stated that besides the curvature other parameters like yarn properties are of essential importance.

scholarly journals Repair of Fire-Damaged Reinforced Concrete Flexural Members: A Review

2019 ◽  
Vol 11 (19) ◽  
pp. 5199 ◽  
Author(s):  
Wenxian Ma ◽  
Chunxiang Yin ◽  
Jun Zhou ◽  
Lu Wang
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
High Performance ◽  
Fiber Reinforced Polymers ◽  
Temperature Sensitive ◽  
Load Bearing Capacity ◽  
Near Surface ◽  
Load Bearing ◽  
Rc Structures ◽  
Externally Bonded

The mechanical properties of both concrete and steel reinforcement, and the load-bearing capacity of reinforced concrete (RC) structures are well known to be temperature-sensitive, as demonstrated by the severe damage that major fires cause in buildings, followed—in extreme cases—by their collapse. Since in most cases RC structures survive a fire, retrofitting fire-damaged RC members is a hot subject today. In this paper, after a recall on the performance of RC beams and slabs in fire, different repair techniques are considered, among them externally bonded reinforcement, near surface-mounted fiber-reinforced polymers (FRP), bolted side plating, jacketing with high- and ultra-high performance concretes or mortars, and damaged-concrete replacement. Last but not least, the design equations aimed at evaluating the residual load-bearing capacity after repairing are also presented and discussed.

scholarly journals Carbon Fiber Strengthening of Geopolymer Concrete Wall Panels with Iron Fillings

2018 ◽  
Vol 7 (4.20) ◽  
pp. 399
Author(s):  
Dr. Wissam K. Al-Saraj ◽  
Dr. Layth Abdulbari Al-Jaberi ◽  
Sahar J. AL-Serai ◽  
. .
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Ultimate Bearing Capacity ◽  
Alkaline Solutions ◽  
Strengthening Effect ◽  
Concrete Wall ◽  
Load Bearing ◽  
Lateral Deflection ◽  
Wall Panels ◽  
Reinforced Concrete Wall

Wall is a vertical plate member resisting vertical (in-plane) or lateral loads. Load-Bearing walls were referred to RC wall panels which were commonly used as load-bearing structural members, braced and laterally supported by the rest of the structure, local materials such as Metakaolin and alkaline solutions are used to cast (600x400) mm reinforced concrete wall panels with 40 mm thickness. To find the ultimate bearing capacity and lateral deflection of wall panels. Seven specimens are divided  in two groups to study the variation effect of iron filling (0, 0.5, 0.75 and  1.0)%   and carbon fiber (225, 125 and 90 )mm spacing center to center of strips.  The result shows that the maximum increasing are 17% and 14% for ultimate bearing capacity and cracking load of wall panels respectively, when iron filling is 1%. Also, the using of carbon fiber with 90 mm spacing center to center of strips leds to increasing in ultimate bearing capacity and cracking load by 31% and 7% respectively. Lateral deflection of wall panels was measured and compared with the reference wall to investigate the strengthening effect. 

Experimental and numerical investigation on the vertical bearing behavior of discrete connected new-type precast reinforced concrete floor system

2020 ◽  
Vol 23 (11) ◽  
pp. 2276-2291
Author(s):  
Rui Pang ◽  
Yibo Zhang ◽  
Longji Dang ◽  
Lanbo Zhang ◽  
Shuting Liang
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cover Plate ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Concrete Floor ◽  
New Type ◽  
Vertical Bearing ◽  
Floor System ◽  
Bearing Behavior

This article proposes a new type of discrete connected precast reinforced concrete diaphragm floor system that consists of precast flat slabs and slab joint connectors. An experimental investigation of discrete connected new-type precast reinforced concrete diaphragm under a vertical distributed static load was conducted, and the effect of slab joint connectors on the load-bearing capacity was evaluated. Then, a finite element analysis of discrete connected new-type precast reinforced concrete diaphragm, precast reinforced concrete floors without slab connectors, and cast-in-situ reinforced concrete floor were performed to understand their working mechanism and determine the differences in load-bearing behavior. The results indicate that the load-bearing capacity and stiffness of discrete connected new-type precast reinforced concrete diaphragm increase considerably as the hairpin and cover plate hybrid slab joint connectors can efficiently connect adjacent precast slabs and enable them to work together under a vertical load by transmitting the shear and moment forces in the orthogonal slab laying direction. The deflection of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction is mainly caused by the opening deformation of the slab joint and the rotational deformation of the precast slabs. This flexural deformation feature can provide reference for establishing the bending stiffness analytical model of discrete connected new-type precast reinforced concrete diaphragm in orthogonal slab laying direction, which is vitally important for foundation of the vertical bearing capacity and deformation calculation method. The deflection and crack distribution patterns infer that the discrete connected new-type precast reinforced concrete diaphragm processes the deformation characteristic of two-way slab floor, which can provide a basis for the theoretical analysis of discrete connected new-type precast reinforced concrete diaphragm.

scholarly journals Load Bearing Capacity Calculation of the System “Reinforced Concrete Beam – Deformable Base” under Torsion with Bending

2019 ◽  
Vol 97 ◽  
pp. 04059 ◽  
Author(s):  
Alexey Dem’yanov ◽  
Vladymir Kolchunov ◽  
Igor Iakovenko ◽  
Anastasiya Kozarez
Keyword(s):  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Cross Sections ◽  
Concrete Beam ◽  
Equations Of State ◽  
Reinforced Concrete Beam ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Deformable Base ◽  
The Relationship

It is presented the formulation and solution of the load bearing capacity of statically indeterminable systems “reinforced concrete beam – deformable base” by spatial cross-sections under force and deformation effects. The solution of problem is currently practically absent in general form. It has been established the relationship between stresses and strains of compressed concrete and tensile reinforcement in the form of diagrams. The properties of the base model connections are described based on a variable rigidity coefficient. It is constructed a system of n equations in the form of the initial parameters method with using the modules of the force (strain) action vector. The equations of state are the dependences that establish the relationship between displacements which are acting on the beam with load. Constants of integration are determined by recurrent formulas. It makes possible to obtain the method of initial parameters in the expanded form and, consequently, the method of displacements for calculating statically indefinable systems. The values of the effort obtained could be used to determine the curvature and rigidity of the sections in this way. It is necessary not to set the vector modulusP, the deformation is set in any section (the module is considered as an unknown) during the problem is solving. This allows us to obtain an unambiguous solution even in the case when the dependence M–χ has a downward section, i.e one value of moment can correspond to two values of curvature.

Stress of Carbon Fiber Reinforced Polymer Tendons in Prestressed Simply Supported Beams

2013 ◽  
Vol 689 ◽  
pp. 353-357
Author(s):  
Chong Xi Bai ◽  
Xin Yan Shao ◽  
Qiu Ping Wang
Keyword(s):  
Carbon Fiber ◽  
Bearing Capacity ◽  
Fiber Reinforced Polymer ◽  
Carbon Fiber Reinforced Polymer ◽  
Fiber Reinforced ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Simply Supported ◽  
Reinforced Polymer ◽  
Carbon Fiber Reinforced

The law of stress increment of unbonded carbon fiber reinforced polymer (CFRP) tendons at service stage and flexural load bearing capacity limit state is unclear, so it is difficult to accurately calculate crack width, deflection and load bearing capacity. In order to calculate the stress of CFRP tendons, deformation compatibility condition and moment-curvature analysis method are used to compile nonlinear full-range analysis programs of simply supported concrete beam partially prestressed with unbonded CFRP tendons. The computing results of stress in CFRP tendons are in good agreement with the tested results as a whole, so it indicates that the simulation analysis programs are reliable.

Sign in / Sign up

Export Citation Format

Share Document