Shear Strength of Concrete and Gypsum Composite Walls

2013 ◽  
Vol 368-370 ◽  
pp. 976-983 ◽  
Author(s):  
Kang Liu

Gypsum walls are a green product that helps to save energy and protect the environment. This paper investigates the shear strength of glass fiber reinforced gypsum (GFRG) walls fully or partially filled with concrete in the hollow cores. Eight full scale GFRG walls were tested. The shear performance of the tested walls, including the shear failure mode, hysteresis responses, the ultimate shear strength were studied in the paper. A design procedure for the shear strength of the concrete filled GFRG walls is developed.

2013 ◽  
Vol 353-356 ◽  
pp. 3623-3629
Author(s):  
Kang Liu

Gypsum walls are a green product that helps to save energy and protect the environment. This paper numerically investigates the effect of axial load on shear strength of glass fiber reinforced gypsum (GFRG) walls fully or partially filled with concrete in the hollow cores. The conclusion drawn in this paper is general and applicable to other kinds of walls.


2006 ◽  
Vol 505-507 ◽  
pp. 37-42 ◽  
Author(s):  
Jia Lin Tsai ◽  
Jui Ching Kuo ◽  
Shin Ming Hsu

This research is aimed to fabricate glass fiber/epoxy nanocomposites containing organoclay as well as to understand the organoclay effect on the in-plane shear strength of the nanocomposites. To demonstrate the organoclay effect, three different loadings of organoclay, were dispersed in the epoxy resin using mechanical mixer followed by sonication. The corresponding glass/epoxy nanocomposites were prepared by impregnating the organoclay epoxy mixture into the dry glass fiber through a vacuum hand lay-up process. Off-axis block glass/epoxy nanocomposites were tested in compression to produce in-plane shear failure. It is noted only the specimens showing in-plane shear failure mode were concerned in this study. Through coordinate transformation law, the uniaxial failure stresses were then converted to a plot of shear stress versus transverse normal stress from which the in-plane shear strength was obtained. Experimental results showed that the fiber/epoxy nanocomposite exhibit higher in-plane shear strength than the conventional composites. This increased property could be ascribed to the enhanced fiber/matrix adhesion promoted by the organoclay.


2013 ◽  
Vol 33 (3) ◽  
pp. 221-227
Author(s):  
Li Fang ◽  
Xuwu Li ◽  
Xiaodong Zhou

Abstract In this article, polypropylene (PP), short glass fiber-reinforced polypropylene (SFT-PP), and direct long glass fiber-reinforced polypropylene (DLFT-PP) interleaves were added as interleaves between fabrics during laminated molding to improve the interlaminar shear strength (ILSS). The test results showed that the ILSS was obviously improved. Furthermore, DLFT-PP interleaves were preheated to melt the PP before laminated molding and were then immediately placed between two fabrics to make the melted PP enter the gaps of the fabric and more fibers were used to further improve the ILSS. As expected, the ILSS increased.


2017 ◽  
Vol 37 (3) ◽  
pp. 247-259
Author(s):  
John Olusanya ◽  
Krishnan Kanny ◽  
Shalini Singh

Abstract The correlation between cure properties and structure of nanoclay filled composite laminate has not been studied extensively. Most of the cure studies were preferably done using small samples through a calorimetric method. In this study, the effect of varying weight ratio of nanoclay (1–5 wt%) on bulk cure properties of epoxy glass fiber reinforced composite (GFRC) laminates was studied. Bulk cure of unfilled and clay filled GFRC laminates was determined using the dynamic mechanical analysis-reheat method (DMA-RM). DMA-RM cure properties gave a better coordinate method, with better cure efficiency achieved in clay filled GFRC laminates when compared to unfilled GFRC laminates. The correlation between nanoclay and DMA-RM degree of cure was coordinated with compressive and in-plane shear strength properties. The degree of cure value of 78% by DMA-RM at 1 wt% clay filled GFRC corresponds with the compressive modulus and in-plane shear strength highest values, which are 20% and 14% increase, respectively, also at 1 wt% clay filled GFRC. The structures of the unfilled and clay filled epoxy were characterized by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Clay filled epoxy up to 3 wt% showed no distinct diffraction peak, which suggested that nanoclay is randomly dispersed in the matrix.


2021 ◽  
Vol 9 (1) ◽  
pp. 72-78
Author(s):  
Osama Daoud ◽  
Ahmed Fadul

The behavior and shear strength of concrete beams reinforced with glass fiber-reinforced polymer (GFRP) bars was investigated. Total of six reinforced concrete beams without stirrups were constructed and tested up to failure. The beams measured 1400 mm long, 150 mm wide and 300 mm deep and were tested in two-points bending with constant shear span 350 mm in all tested beams, and shear span to depth ratio a/d 1.37. The test variable was the reinforcement ratio. The test beams included three beams designed as tension control (T.C) with GFRP bars, three beams designed as compression control (C.C) with GFRP bars. The test results were compared with predictions provided by ACI 440.1R-15 design guideline and proposed equations in the literature. The test results indicated that the relatively low modulus of elasticity of FRP bars resulted in reducing shear strength. In addition, shear strength provided by ACI 440.1R-15 guideline underestimate shear strength capacity in which proposed equations in the literature had given better prediction than ACI 440.1R-15. The failure mode in T.C beams is diagonal tension by bond failure not by rupture of FRP and C.C beams is shear compression by crushing of the web in extreme fiber.  


2020 ◽  
Vol 6 (10) ◽  
pp. 1852-1863
Author(s):  
Jun-Hyeok Song ◽  
Eun-Taik Lee ◽  
Hee-Chang Eun

Aged structures and structures constructed based on outdated non-seismic design codes should be retrofitted to enhance their strength, ductility, and durability. This study evaluates the structural performance of reinforced concrete (RC) columns enhanced via polyurea or glass fiber reinforced polyurea (GFRPU) strengthening. Four RC column specimens, including a reference specimen (an unstrengthened column), were tested to evaluate the parameters of the strengthening materials and the strengthened area. The tests were carried out under a combined constant axial compressive load and quasi-static cyclic loading. The experimental results show that the composite strengthening provides lateral confinement to the columns and leads to enhanced ductility, shear-resistance capacity, and dissipated energy. The shear strength provided by the composites depends on the degree of lateral confinement achieved by the composite coating. The specimens finally failed through the development of diagonal tension cracks within the potential plastic hinge regions. The specimen treated with GFRPU strengthening showed greater strength and dissipated more energy than the specimen treated with polyurea strengthening. Furthermore, by modifying ATC-40, this study proposed an equation to estimate the shear capacity provided by the composites.


2018 ◽  
Vol 26 (1) ◽  
pp. 111-118
Author(s):  
Min Sook Kim ◽  
Joowon Kang ◽  
Young Hak Lee

This paper discusses the experimental results on the shear behavior of concrete wide beams reinforced with glass fiber reinforced polymer (GFRP) plates as shear reinforcement. In order to examine the shear performance, a total of six concrete wide beams were manufactured and tested. All the specimens were designed to have the same number of legs of shear reinforcement. The transverse spacing of shear reinforcement was considered as a variable to investigate the influence of transverse spacing of concrete wide beams. From the test results, it is observed that the shear strength increased when transverse spacing of the shear reinforcement decreased. In addition, an equation is proposed to predict the shear strength of concrete wide beams in order to consider the influence of transverse spacing of the shear reinforcement. The equation is based on the test results and modified ACI 318–14. It is verified that the proposed equation is considered to be better than ACI 318–14.


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