scholarly journals Bending Stiffness, Load-Bearing Capacity and Flexural Rigidity of Slender Hybrid Wood-Based Beams

Forests ◽  
2018 ◽  
Vol 9 (11) ◽  
pp. 703 ◽  
Author(s):  
Barbara Šubic ◽  
Gorazd Fajdiga ◽  
Jože Lopatič
Keyword(s):  
Bearing Capacity ◽  
Flexural Rigidity ◽  
Bending Stiffness ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Hybrid Beams ◽  
Fibre Reinforced Polymer

Modern architecture suggests the use of opened spaces with large transparent envelope surfaces. Therefore, windows of long widths and large heights are needed. In order to withstand the wind loads, such wooden windows can be reinforced with stiffer materials, such as aluminium (Al), glass-fibre reinforced polymer (GFRP), and carbon-fibre reinforced polymer (CFRP). The bending stiffness, load-bearing capacity, and flexural rigidity of hybrid beams, reinforced with aluminium, were compared through experimental analysis, using a four-point bending tests method, with those of reference wooden beams. The largest increases in bending stiffness (29%–39%), load-bearing capacity (33%–45%), and flexural rigidity (43%–50%) were observed in the case of the hybrid beams, with the highest percentage of reinforcements (12.9%—six reinforcements in their tensile and six reinforcements in their compressive zone). The results of the experiments confirmed the high potential of using hybrid beams to produce large wooden windows, for different wind zones, worldwide.

Experimental Study on Seismic Behavior of Masonry Walls with Window Openings Strengthened with Sprayed GFRP

2015 ◽  
Vol 744-746 ◽  
pp. 113-117
Author(s):  
Cheng Fang Sun ◽  
Chun Ming Chen ◽  
Qian Gu
Keyword(s):  
Seismic Behavior ◽  
Critical Role ◽  
Masonry Walls ◽  
Cfrp Sheets ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Hysteresis Response

A contrast investigation of the seismic behavior of unreinforced masonry walls with window openings strengthened with Carbon Fibre Reinforced Polymer (CFRP) sheets and sprayed Glass Fibre Reinforced Polymer (GFRP) is presented. Three wall specimens in the scale of 1/2 were tested by the horizontal cyclic loading combined with constant gravity loads. The seismic strengthening effects by two different FRP retrofitting schemes are compared in aspect of the hysteresis response, deterioration of rigidity and ability of energy dissipation. The experimental results indicate that the increasing degree of the improvement of seismic behavior of the SGFRP-strengthened wall are significantly superior to that of the wall strengthened with epoxy-based CFRP; and the overcoat of sprayed GFRP can bond tightly and work well together with the masonry to play a critical role in earthquake resistance.

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.

Static and fatigue investigation of innovative second-generation steel-free bridge decks

2007 ◽  
Vol 34 (3) ◽  
pp. 331-339 ◽  
Author(s):  
C Klowak ◽  
A Memon ◽  
A A Mufti
Keyword(s):  
Second Generation ◽  
Bridge Deck ◽  
Fatigue Testing ◽  
Fatigue Behavior ◽  
The Other ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

This paper outlines the static and fatigue behavior of cast-in-place, second-generation steel-free bridge decks. Although cast monolithically, the first bridge deck was divided into three segments. The first segment was reinforced with steel, according to conventional design. The other two segments were steel-free designs with internal crack-control grids, one consisting of carbon-fibre-reinforced polymer (CFRP) and the other consisting of glass-fibre-reinforced polymer (GFRP). This hybrid CFRP or GFRP and steel strap design is called the second generation of the steel-free concrete bridge deck. The hybrid system limits the width of any longitudinal cracks that develop and eliminates corrosion from within the deck slab. All three segments were tested under cyclic loads of 222 and 588 kN to investigate fatigue behavior. The second bridge deck comprises an internal panel and two cantilevers and also incorporates a complete civionics system. The static tests outlined in this paper are useful in the development of the fatigue theory, which was derived from the fatigue testing of the first bridge deck.Key words: steel-free, cantilever, fatigue testing, static testing, glass-fibre-reinforced polymer, carbon-fibre-reinforced polymer, civionics.

scholarly journals Load-Bearing Capacity of Beams Reinforced with Composite Rebar in Regard to Existing Guidelines

Materials ◽  
2021 ◽  
Vol 14 (20) ◽  
pp. 6116
Author(s):  
Norbert Olczyk ◽  
Jarosław Błyszko ◽  
Mateusz Techman
Keyword(s):  
Bearing Capacity ◽  
Experimental Tests ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Gfrp Bars ◽  
Reinforced Polymer ◽  
Steel Bars ◽  
Limited Application ◽  
Proper Design ◽  
Metallic Reinforcement

Non-metallic reinforcement such as fiber-reinforced polymer (FRP) is now being increasingly used in construction. Despite numerous similarities, elements reinforced with non-metallic bars work differently from the ones reinforced with steel bars, including cracking and failure mode. The examination of the stress state in these elements, so important for their proper design, raises many difficulties. The article presents the results of tests of bended beams reinforced with GFRP bars. The results of the experimental tests were compared with calculations based on selected design instructions. The results have shown that beams reinforced with GFRP exhibit increased cracking, higher deflection, and often mode of failure through crushing of concrete. The results have shown that in bended elements reinforced with the GFRP bars, the rebar often does not achieve the strength declared by the manufacturer. The study has shown that theoretical values of load-bearing capacity of beams reinforced with composite rebar differ greatly between different guidelines and instruction. The analysis showed that the use of GFRP bars as a replacement for steel bars is possible in demanding environmental conditions. However, excessive deflections and cracks may result in limited application due to overall serviceability requirements of the element.

scholarly journals Evaluation of Strength Characteristics of Concrete by Glass Fibre Reinforced Polymer (GFRP) And Carbon Fibre Reinforced Polymer (CFRP) Wrapping

2021 ◽  
Vol 9 (VIII) ◽  
pp. 831-836
Author(s):  
Shalini G V
Keyword(s):  
Construction Projects ◽  
Construction Material ◽  
Rc Structures ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Operational Life ◽  
Compressive Loads ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced

The construction material mainly reinforced concrete is being used extensively for various type of construction projects. However, deterioration of RC structures is recognized as a major problem worldwide. Extension of the structures’ life is an inevitable need for a healthy planet. Any deficiency caused to the members of the structure may affect the life of structure. Therefore, it is important that the members should provide adequate strength (for which it is designed) throughout its operational life. But, it has been observed that due to alteration in purpose of use of structure (very common in mega cities), improper design and deficiency caused due to earthquake, blast and impacts in structural members and as a result in the members structure can possibly be subjected to loads which have higher magnitude compared to its design loads. This study is based on experimental investigation to assess the behavior of CFRP & GFRP wrapped concrete under compressive loads. For this purpose, M30 grade concrete specimens have been casted and wrapped it with Glass and Carbon FRP and its strength against compressive loads have been found.

scholarly journals Steel Fibres: Effective Way to Prevent Failure of the Concrete Bonded with FRP Sheets

2016 ◽  
Vol 2016 ◽  
pp. 1-10 ◽  
Author(s):  
V. Gribniak ◽  
A. K. Arnautov ◽  
A. Norkus ◽  
R. Kliukas ◽  
V. Tamulenas ◽  
...  
Keyword(s):  
Structural Behaviour ◽  
Cracking Resistance ◽  
Steel Fibres ◽  
Reinforced Polymer ◽  
Glass Fibre Reinforced Polymer ◽  
Externally Bonded ◽  
Carbon Fibre Reinforced Polymer ◽  
Fibre Reinforced Polymer ◽  
Glass Fibre Reinforced ◽  
Failure Character

Although the efficiency of steel fibres for improving mechanical properties (cracking resistance and failure toughness) of the concrete has been broadly discussed in the literature, the number of studies dedicated to the fibre effect on structural behaviour of the externally bonded elements is limited. This experimental study investigates the influence of steel fibres on the failure character of concrete elements strengthened with external carbon fibre reinforced polymer sheets. The elements were subjected to different loading conditions. The test data of four ties and eight beams are presented. Different materials were used for the internal bar reinforcement: in addition to the conventional steel, high-grade steel and glass fibre reinforced polymer bars were also considered. The experimental results indicated that the fibres, by significantly increasing the cracking resistance, alter the failure character from splitting of the concrete to the bond loss of the external sheets and thus noticeably increase the load bearing capacity of the elements.

Experimental Study on Residual Load Bearing Capacity of SRC Eccentric Columns after Exposure to Fire

2010 ◽  
Vol 163-167 ◽  
pp. 2240-2246 ◽  
Author(s):  
Jun Hua Li ◽  
Yue Feng Tang ◽  
Ming Zhe Liu
Keyword(s):  
Mechanical Properties ◽  
Reinforced Concrete ◽  
Bearing Capacity ◽  
Ultimate Strength ◽  
Room Temperature ◽  
Ultimate Load ◽  
Flexural Rigidity ◽  
Load Bearing Capacity ◽  
Load Bearing ◽  
Steel Reinforced Concrete

This paper provided three test data pertaining to the mechanical properties of steel reinforced concrete (SRC) eccentric columns after exposure to fire and one comparative test data pertaining to the mechanical properties of steel reinforced concrete columns at room temperature. The influence of eccentricity on failure mode, distortion performance and ultimate load bearing capacity are mainly studied. Test results show that the failure modes of steel reinforced concrete eccentric columns after exposure to fire are similar to that at room temperature. Strain along the section height at mid-span section of eccentric columns before loaded to 90% ultimate load bearing capacity is linearly distributed and well agree with the plane section supposition. After exposure to fire, the flexural rigidity and load bearing capacity of specimens are all declined compared with that at normal temperature. In various loading stages from the initial loading to 80% ultimate strength, the ratio of flexural rigidity of SRC eccentric columns after exposure to fire and at normal temperature is ranged from 0.30 to 0.59. With the same concrete strength and heating condition, the ultimate strength of specimens decreases with the increasing of eccentricity. The ultimate bearing capacity of all specimens at normal room temperature is calculated on the method proposed by Chinese regulation JGJ 138-2001. The compared results of experimental values and calculating values show that the residual load bearing capacity of SRC eccentric columns after exposure to fire is about 69% to 81% of that at room temperature.

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