scholarly journals Studies on stress-strain behaviour of concrete mixes confined with BFRP rebars

2021 ◽  
Vol 309 ◽  
pp. 01049
Author(s):  
K Ajay Kumar ◽  
A Venkat Sai Krishna ◽  
S Shrihari ◽  
V Srinivasa Reddy
Keyword(s):  
Ultimate Load ◽  
Load Carrying Capacity ◽  
Basalt Fibre ◽  
Stress Strain ◽  
Reinforced Polymer ◽  
Strain Behaviour ◽  
Load Carrying ◽  
Fibre Reinforced Polymer ◽  
Ultimate Load Carrying Capacity ◽  
Steel Rebars

In the present study, the stress-stain behaviour of confined concrete made with basalt fibre reinforced polymer bars (BFRP) were taken up. The stress-strain behaviour was studied for the concrete mixes confined with steel rebars and BFRP rebars. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of basalt fibres along with confinement of concrete with steel and BFRP hoops enhanced the compressive strength, indicating further confinement effect in the concrete. It is observed that the addition of fibres is helpful in lower confinements only. Beyond 1.1% confinement, the addition of any type of basalt fibres doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of concrete mixes, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in concrete with BFRP hoops for mixes up to 1.1% confinement. The addition of basalt fibres to concrete has increased the ductility in both confined and unconfined states

scholarly journals Stress - strain behaviour of confined nano silica-based concrete

2021 ◽  
Vol 309 ◽  
pp. 01048
Author(s):  
Kakara S J Kumar ◽  
M V Seshagiri Rao ◽  
V Srinivasa Reddy ◽  
S Shrihari
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Confined Concrete ◽  
Load Carrying Capacity ◽  
Nano Silica ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Steel Rebars

In the present study, the stress-stain behaviour of confined concrete made with nano-silica (nano-SiO2) were taken up. The stress-strain behaviour was studied for the M30 and M50 grades nano-silica (nano-SiO2) concrete mixes confined with steel rebars. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of nano-silica (nano-SiO2) along with confinement of concrete with steel hoops enhanced the compressive strength, indicating further confinement effect in the concrete. It is observed that the addition of nano-silica (nano-SiO2) is helpful in lower confinements only. Beyond 1.1% confinement, doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of concrete mixes, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in nano-silica (nano-SiO2) concrete with steel hoops for mixes up to 1.1% confinement. The addition of nano-silica (nano-SiO2) to concrete has increased the ductility in both confined and unconfined states

scholarly journals Studies on stress- strain behaviour of fibre reinforced self-compacting concrete in confined state

2021 ◽  
Vol 309 ◽  
pp. 01054
Author(s):  
Gorla Jayasri ◽  
V Siva Prasad Raju ◽  
V Srinivasa Reddy ◽  
M Mounika
Keyword(s):  
Compressive Strength ◽  
Carrying Capacity ◽  
Ultimate Load ◽  
Confinement Effect ◽  
Load Carrying Capacity ◽  
Self Compacting Concrete ◽  
Stress Strain ◽  
Strain Behaviour ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity

In the present study, the stress-stain behaviour of self-compacting concrete (SCC) and fibre reinforced self-compacting concrete (FRSCC) were taken up. The stress-strain behaviour was studied for the SCC and FRSCC mixes in unconfined and confined states. The confinement was given in the form of steel hoops in the cylinders, 3 hoops (0.8%), 4 hoops (1.1%), 5 hoops (1.3%) and 6 hoops (1.6%). The addition of fibres along with confinement of FRSCC with steel hoops enhanced the compressive strength, indicating further confinement effect in the FRSCC. It is observed that the addition of fibres is helpful in lower confinements only. Beyond 1.1% confinement, the addition of any type of fibres doesn’t show any effect on compressive strengths. From the stress-strain behaviour of all types of FRSCC, it is concluded that the ultimate load-carrying capacity and strains at peak stresses are more in SFRSCC and HFRSCC for mixes up to 1.1% confinement. The addition of fibres to SCC has increased the ductility in both confined and unconfined states

scholarly journals Flexural Behaviour Of Strengthened RC Beams With Multi-Directional Basalt Fibre - Reinforced Polymer Composites

2015 ◽  
Vol 61 (1) ◽  
pp. 45-58 ◽  
Author(s):  
A. Chandran ◽  
M. Neelamegam
Keyword(s):  
Ultimate Load ◽  
Compressive Strain ◽  
Basalt Fibre ◽  
Reinforced Polymer ◽  
Load Carrying ◽  
External Strengthening ◽  
Fibre Reinforced Polymer ◽  
Bottom Face ◽  
Ultimate Load Carrying Capacity ◽  
Different Characteristics

AbstractThe paper describes an experimental behaviour of the basalt fibre reinforced polymer composite by external strengthening to the concrete beams. The BFRP composite is wrapped at the bottom face of R.C beam as one layer, two layers, three layers and four layers. The different characteristics - are studied in - first crack load, ultimate load, tensile and compressive strain, cracks propagation, crack spacing and number of cracks etc. To - investigate, total of five beams size 100mm× 160mm×1700mm were cast. One beam is taken as control and others are strengthened with BFRP composite with layers. From this investigation, the first crack load is increased depending on the increment in layers from 6.79% to 47.98%. Similarly, the ultimate load carrying - capacity is increased from 5.66% to 20%. The crack’s spacing is also reduced with an increase in the number of layers

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.

STRESS-STRAIN RELATIONSHIPS OF COMPOSITE FOAMED CONCRETE PANEL WITH DIFFERENT NUMBER OF SHEAR CONNECTORS UNDER COMPRESSION

2015 ◽  
Vol 75 (5) ◽  
Author(s):  
M. A. Othuman Mydin ◽  
N. Utaberta ◽  
M. Y. Mohd Yusof ◽  
N. A. Amirudin
Keyword(s):  
Carrying Capacity ◽  
Ultimate Load ◽  
Strain Curve ◽  
Sandwich Composite ◽  
Load Carrying Capacity ◽  
Stress Strain ◽  
Shear Connectors ◽  
Load Carrying ◽  
Foamed Concrete ◽  
Ultimate Load Carrying Capacity

The present of the shear connectors with the sandwich composite foamed concrete panel system is to increase the strength of the panel. Therefore the objectives of experiment on effects of the shear connectors spacing is to determine the influence of shear connectors spacing on the axial stress-strain curve, to observe the failure mode sandwich composite foamed concrete panel system with different shear connectors spacing, and to establish ultimate load carrying capacity of different shear connectors spacing. In this study, there are four samples of shear connectors spacing which are 5, 7, 9 and 13 to composited foamed concrete with density of 1400 kg/m3 and 700 kg/m3. This study has showed the enhancement of ultimate compressive strength with increasing numbers of mechanical connectors. The failure of mode observed proved that sandwich panel failures decreasing with enhancement numbers of mechanical connectors, thus sandwich panels can sustained ultimate load carrying capacity.  

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.

scholarly journals Analysis of Ultimate Load-Carrying Capacity of Combined Connection with Bolts and Welds

Mechanika ◽  
2019 ◽  
Vol 25 (6) ◽  
pp. 426-433 ◽  
Author(s):  
Tao LAN
Keyword(s):  
Ultimate Load ◽  
High Strength ◽  
Shear Plane ◽  
Deformation Capacity ◽  
Load Carrying Capacity ◽  
Element Calculation ◽  
Lap Splices ◽  
Load Carrying ◽  
Ultimate Load Carrying Capacity ◽  
Longitudinal Welds

In this paper, load-carrying and deformation capacity of tension lap splices that have both welds and bolts acting in the same shear plane are studied using numerical method. The failure criterion of bolts and welds are given based on the finite element calculation and compared with existing experiment results, it shows that the established numerical model is correct and reliable. The strength of longitudinal welds and the bearing capacity of the high-strength bolts before slipping can be fully used in the combined joints, the bolts and welds fail almost simultaneously. The deformation of welds in combined connections is less uniform than its’ deformation in welded joints as the welds fails, and it causes the deformation of welds as failure is larger in combined connections than in welded connections. The deformation capacity of the combined joint are slightly increased contrasted with bolts joint and welds joint because of the interplay of bolts and welds acting in the same shear plane. The strengths of welds and bolts performed in combined connections can reach 0.95 and the deformation of combined connection is increased at least 1.10 times as the welds connection or the bolts connection.

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.

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