scholarly journals Repairing of Reactive Powder Concrete T-Beams Containing Web Opening by CFRP Strips

2019 ◽  
Vol 26 (1) ◽  
pp. 9-19
Author(s):  
Mazin B. Abdulrahman ◽  
Husham M. Rashid
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Experimental Program ◽  
Reactive Powder Concrete ◽  
Shape Effect ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Reactive Powder

In modern buildings, transverse openings are often used beams for the purpose of supplying and service pipes. Due to the presence of the openings in the concrete beams lead to the formation of cracks around the openings due to the stresses concentration in a small area above and below of the opening. The repairing, maintenance, and upgrading of structural members, are maybe one of the most pivotal problems in civil engineering applications. In this research, an experimental work is conducted to study the behavior of the reinforced RPC T-beams that containing openings and repair this beams using CFRP strips. The Experimental program of the present study includes two parts, the first part includes testing of seven reinforced reactive powder concrete RPC T-beams, which casted and tested, one beam is without opening as a reference beam and the rest, were provided with an opening. and these beams are divided into two groups. The first group was used to study the effect of the openings shape (circular and square) and the second group was used to study the effect of the openings locations, which consists three locations (Lc/2, Lc/3 and Lc/4).These are measured from the support center to the openings center. While the second part including a repaired all beams in the first part the using carbon fiber polymer. The test results indicated that the presence of openings in the beams web caused a reduction in the reinforced RPC T-beams ultimate load carrying capacity with about (10-55)%, Also lead to increasing in deflection compared to control beam before repairing at same loading. Studying the shape effect showed that the beams with square openings have average ultimate load carrying capacity lower by 36% compared with the control beams.While beams with containing circular openings have average ultimate load carrying capacity lower 29%. From the test results, it could be concluded that the presence of the openings in the shear region led to a decrease in ultimate load carrying capacity a about 38% to 49% for opening of opening at (Lc/3 and Lc/4) respectively. While the presence of openings in the flexural region led to a decrease in the ultimate load carrying capacity rate of 11%. Related to the repairing study part it was found that the average ultimate load carrying capacity for repairing beams was 103% compared with the not repaired beams.

Evaluation on ultimate load-carrying capacity of concrete-filled steel tubular arch structure with preload

2019 ◽  
Vol 22 (13) ◽  
pp. 2755-2770
Author(s):  
Fuyun Huang ◽  
Yulong Cui ◽  
Rui Dong ◽  
Jiangang Wei ◽  
Baochun Chen
Keyword(s):  
Finite Element ◽  
Initial Stress ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Arch Bridge ◽  
Load Carrying ◽  
Arch Structure ◽  
Ultimate Load Carrying Capacity

When casting wet concrete into hollow steel tubular arch during the construction process of a concrete-filled steel tubular arch bridge, an initial stress (due to dead load, etc.) would be produced in the steel tube. In order to understand the influence of this initial stress on the strength of the concrete-filled steel tubular arch bridge, a total of four single tubular arch rib (bare steel first) specimens (concrete-filled steel tubular last) with various initial stress levels were constructed and tested to failure. The test results indicate that the initial stress has a large influence on the ultimate load-carrying capacity and ductility of the arch structure. The high preloading ratio will reduce significantly the strength and ductility that the maximum reductions are over 25%. Then, a finite element method was presented and validated using the test results. Based on this finite element model, a parametric study was performed that considered the influence of various parameters on the ultimate load-carrying capacity of concrete-filled steel tubular arches. These parameters included arch slenderness, rise-to-span ratio, loading method, and initial stress level. The analysis results indicate that the initial stress can reduce the ultimate loading capacity significantly, and this reduction has a strong relationship with arch slenderness and rise-to-span ratio. Finally, a method for calculating the preloading reduction factor of ultimate load-carrying capacity of single concrete-filled steel tubular arch rib structures was proposed based on the equivalent beam–column method.

scholarly journals Eigenproblem Versus the Load-Carrying Capacity of Hybrid Thin-Walled Columns with Open Cross-Sections in the Elastic Range

Materials ◽  
2021 ◽  
Vol 14 (13) ◽  
pp. 3468
Author(s):  
Zbigniew Kolakowski ◽  
Andrzej Teter
Keyword(s):  
Cross Sections ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Equilibrium Path ◽  
Load Carrying Capacity ◽  
Nonlinear Buckling ◽  
Elastic Range ◽  
Load Carrying ◽  
Thin Walled ◽  
Ultimate Load Carrying Capacity

The phenomena that occur during compression of hybrid thin-walled columns with open cross-sections in the elastic range are discussed. Nonlinear buckling problems were solved within Koiter’s approximation theory. A multimodal approach was assumed to investigate an effect of symmetrical and anti-symmetrical buckling modes on the ultimate load-carrying capacity. Detailed simulations were carried out for freely supported columns with a C-section and a top-hat type section of medium lengths. The columns under analysis were made of two layers of isotropic materials characterized by various mechanical properties. The results attained were verified with the finite element method (FEM). The boundary conditions applied in the FEM allowed us to confirm the eigensolutions obtained within Koiter’s theory with very high accuracy. Nonlinear solutions comply within these two approaches for low and medium overloads. To trace the correctness of the solutions, the Riks algorithm, which allows for investigating unsteady paths, was used in the FEM. The results for the ultimate load-carrying capacity obtained within the FEM are higher than those attained with Koiter’s approximation method, but the leap takes place on the identical equilibrium path as the one determined from Koiter’s theory.

Experimental study on the axial compression performance of GFRP-reinforced concrete square columns

2018 ◽  
Vol 22 (7) ◽  
pp. 1554-1565 ◽  
Author(s):  
Jianwei Tu ◽  
Kui Gao ◽  
Lang He ◽  
Xinping Li
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Longitudinal Reinforcement ◽  
Rc Columns ◽  
Compression Performance ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

At present, extensive studies have been conducted relative to the topic of fiber-reinforced polymer(FRP)- reinforced concrete (RC) flexural members, and many design methods have also been introduced. There have, however, been few studies conducted on the topic of FRP-RC compression members. In light of this, eight glass-fiber-reinforced polymer (GFRP)-RC square columns (200×200×600 mm) were tested in order to investigate their axial compression performance. These columns were reinforced with GFRP longitudinal reinforcement and confined GFRP stirrup. These experiments investigated the effects of the longitudinal reinforcement ratio, stirrup configuration (spirals versus hoops) and spacing on the load-carrying capacity and failure modes of GFRP-RC rectangular columns. The test results indicate that the load-carrying capacity of longitudinal GFRP bars accounted for 3%-7% of the ultimate load-carrying capacity of the columns. The ultimate load-carrying capacity of RC columns confined with GFRP spirals increased by 0.8%-1.6% with higher ductility, compared to GFRP hoops. Reducing the stirrup spacing may prevent the buckling failure of the longitudinal bars and increase the ductility and load-carrying capacity of the GFRP-RC columns. It has been found that setting the GFRP compressive strength to 35% of the GFRP maximum tensile strength yields a reasonable estimate of ultimate load-carrying capacity of GFRP-RC columns.

Structural Performance of Fiber-Reinforced Polymer Honeycomb Sandwich Panels: Evaluation of Size Effect and Wrap Strengthening

2003 ◽  
Vol 1845 (1) ◽  
pp. 191-199 ◽  
Author(s):  
Ondrej Kalny ◽  
Robert J. Peterman ◽  
Guillermo Ramirez ◽  
C. S. Cai ◽  
Dave Meggers
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Sandwich Panels ◽  
Fiber Reinforced Polymer ◽  
Load Carrying Capacity ◽  
Flexural Capacity ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
Honeycomb Sandwich ◽  
Ultimate Load Carrying Capacity

Stiffness and ultimate load-carrying capacities of glass fiber-reinforced polymer honeycomb sandwich panels used in bridge applications were evaluated. Eleven full-scale panels with cross-section depths ranging from 6 to 31.5 in. (152 to 800 mm) have been tested to date. The effect of width-to-depth ratio on unit stiffness was found to be insignificant for panels with a width-to-depth ratio between 1 and 5. The effect of this ratio on the ultimate flexural capacity is uncertain because of the erratic nature of core-face bond failures. A simple analytical formula for bending and shear stiffness, based on material properties and geometry of transformed sections, was found to predict service-load deflections within 15% accuracy. Although some factors influencing the ultimate load-carrying capacity were clearly identified in this study, a reliable analytical prediction of the ultimate flexural capacity was not attained. This is because failures occur in the bond material between the outer faces and core, and there are significant variations in bond properties at this point due to the wet lay-up process, even for theoretically identical specimens. The use of external wrap layers may be used to shift the ultimate point of failure from the bond (resin) material to the glass fibers. Wrap serves to strengthen the relatively weak core–face interface and is believed to bring more consistency in determining the ultimate load-carrying capacity.

Load-Carrying Capacity of Second-Growth Douglas-Fir Stump Anchors

1987 ◽  
Vol 2 (3) ◽  
pp. 77-80 ◽  
Author(s):  
Marvin R. Pyles ◽  
Joan Stoupa
Keyword(s):  
Carrying Capacity ◽  
Deformation Behavior ◽  
Ultimate Load ◽  
Douglas Fir ◽  
Load Carrying Capacity ◽  
Test Results ◽  
Tree Diameter ◽  
Second Growth ◽  
Load Carrying ◽  
Load Tests

Abstract In order to quantify the stump anchor capacity of small second-growth Douglas-fir (Pseudotsuga menziesii [Mirb]. Franco) trees, load tests to failure were conducted on 18 stumps from trees 7 to 16.5 in dbh. The tests produced ultimate loads that varied as the square of the tree diameter. However, the ultimate load typically occurred at stump system deformations that were far in excess of that which would be considered failure of a stump anchor. A hyperbolic equation was used to describe the load-deformation behavior of each stump tested and was generalized to describe all the test results. West. J. Appl. For. 2(3):72-80, July 1987.

Structural Behaviour of Precast Lightweight Foamed Concrete Sandwich Panel (PLFP) with Double Shear Truss Connectors under Axial Load: Preliminary Result

2013 ◽  
Vol 795 ◽  
pp. 190-194
Author(s):  
S. Samsuddin ◽  
I. Ahmad ◽  
W.I. Goh ◽  
N. Mohamad ◽  
Abdul Aziz Abdul Samad ◽  
...  
Keyword(s):  
Experimental Data ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Axial Loading ◽  
Load Carrying Capacity ◽  
Structural Behaviour ◽  
Double Shear ◽  
Load Carrying ◽  
Foamed Concrete ◽  
Ultimate Load Carrying Capacity

This report provides experimental data on the development of PLFP for building construction. An innovative concept was used in the design of this system and the use of lightweight foamed concrete was discussed. Preliminary result of PLFP with double shear truss connectors was analysed and presented. PLFP was tested to determine its ultimate load carrying capacity under axial loading. Ultimate load carrying capacity, load deflection profile, surface strains and crack pattern were recorded and analysed. Test results were compared with calculated values based on classical formulas that developed by previous researchers and experimental data from previous researchers on its compositeness in between wythes. Results shown that PLFP with double shear truss connectors achieved higher compositeness in between wythes and have adequate ultimate load carrying capacity.

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