scholarly journals Comparative deformability of compressive members reinforced with steel and GFRP reinforcement

2018 ◽  
Vol 251 ◽  
pp. 02036
Author(s):  
Andrey Lapshinov ◽  
Pavel Deminov
Keyword(s):  
Modulus Of Elasticity ◽  
Volumetric Strain ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Stress Strain ◽  
Strain Stress ◽  
Transverse Strains ◽  
Gfrp Reinforcement ◽  
Small Spacing

The paper contains the results of testing of compressive members reinforced longitudinally and transversally with steel and GFRP reinforcement. The spacing of transverse reinforcement (stirrups) and longitudinal reinforcement ratio varied in the specimens. The stress-strain, stress-Poisson’s ration, stress-volumetric strain relationships for tested specimens are given. It was observed that the appearance of cracks occurred with loading 90% of total. By the results of testing investigated that with the decreasing of spacing of transverse reinforcement the strength of specimens increased. Conclusion is made that by using small spacing of transverse reinforcement transverse strains and Poisson’s ratio decreasing, while modulus of elasticity increasing.

Sectional Ductility of Wide Beams

2021 ◽  
Author(s):  
Ornela Lalaj Şen ◽  
Mehmet Çevik ◽  
Ali Haydar Kayhan
Keyword(s):  
Aspect Ratio ◽  
Reinforcement Ratio ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Beam Structures ◽  
Wide Beam ◽  
The Mean ◽  
The Moment ◽  
Wide Beams ◽  
High Seismicity

Wide beam structures are categorized as Limited Ductility Class in Turkey and elsewhere and considered not fit for construction in areas of high seismicity. One of the main reasons that wide beam structures are considered to possess limited ductility is the perceived low local ductility of the wide beams, due to the high reinforcement ratios. Wide beams have small depths, which indeed require higher reinforcement ratios to produce the necessary moment capacities, as compared to normal beams. However, the low local ductility of the wide beams can be contested. This paper presents a database of more than 150 beam sections, some of which are normal and some of which are wide beams. The moment-rotation relationships were computed for all the sections, and the sectional ductility was calculated from the yield and ultimate rotations. The relations between sectional ductility and other parameters such as section aspect ratio, longitudinal reinforcement ratio and transverse reinforcement ratio were investigated. An example of the relation between ductility and section properties, in this case section aspect ratio is shown. Both positive and negative ductility were calculated and plotted. It should be noted that beams with section ratio of 0.5 are conventional beams, while the rest are wide beams. The values of ductility vary for all beams, and conventional beams have a slightly wider spread. While these parameters vary within the section database, the sectional ductility oscillates around 30, and no clear correlations could be established for any of the above-mentioned parameters. There were no significant differences between the average sectional ductility of conventional and wide beams. For this dataset, the mean positive ductility was 29.66 and 29.33 for conventional and wide beams respectively, and the mean negative ductility was 28.96 and 31.50 for conventional and wide beams, respectively.

scholarly journals Settlement Response of a Multi-Story Building

2020 ◽  
Vol 10 (5) ◽  
pp. 6220-6223
Author(s):  
A. H. Bhutto ◽  
G. S. Bhurgri ◽  
S. Zardari ◽  
M. A. Zardari ◽  
B. A. Memon ◽  
...  
Keyword(s):  
Constitutive Model ◽  
Soil Properties ◽  
Modulus Of Elasticity ◽  
Stress Strain ◽  
Settlement Calculation ◽  
Allowable Range ◽  
Reliable Representation ◽  
Coulomb Model ◽  
Story Building ◽  
Hardening Soil Model

The settlement calculation of a multi-story building is a challenging task due to the variation of soil properties and the use of an appropriate constitutive model for the reliable representation of soils’ stress-strain behaviors. In this study, the settlement response of a multi-story building was calculated with the simple Mohr-Coulomb Model (MCM) and the Hardening Soil Model (HSM). The effect of soil modulus of elasticity using both models was investigated on the overall settlement response of the building. Results indicated that MCM overestimated immediate settlement in a range of 50 to 65% compared to HSM. The settlement response of the building calculated with both models was within the allowable range. The results of this study can be helpful for geotechnical engineers working on reliable predictions of the settlement of multi-story buildings.

scholarly journals Research on Concrete Columns Reinforced with New Developed High-Strength Steel under Eccentric Loading

2019 ◽  
Author(s):  
Yonghui Hou ◽  
Shuangyin Cao ◽  
Xiangyong Ni ◽  
Yizhu Li
Keyword(s):  
Yield Strength ◽  
Bearing Capacity ◽  
High Strength Steel ◽  
High Strength ◽  
Concrete Columns ◽  
Lower Amount ◽  
Transverse Reinforcement ◽  
Longitudinal Reinforcement ◽  
Small Eccentricity ◽  
Failure Patterns

The use of new developed high-strength steel in concrete members can reduce steel bars congestion and construction costs. This research aims to study the behavior of concrete columns reinforced with new developed high-strength steel under eccentric loading. Ten reinforced concrete columns were fabricated and tested. The test variables are transverse reinforcement amount and yield strength, eccentricity, and longitudinal reinforcement yield strength. The failure patterns are compression and tensile failure for columns subjected to small eccentricity and large eccentricity, respectively. The same level of post-peak deformability and ductility only can be obtained with lower amount of transverse reinforcement when high-strength transverse reinforcements are used in columns subjected to small eccentricity. The high-strength longitudinal reinforcement can improve bearing capacity and post-peak deformability of concrete columns. Besides, three different equivalent rectangular stress block (ERSB) parameters in predicting bearing capacity of columns with high-strength steel were discussed based on test and simulated results. It is concluded that the Code of GB 50010-2010 overestimates the bearing capacity of columns with high-strength steel, whereas bearing capacities computed using Codes of ACI 318-14 and CSA A23.3-04 agree well with test results.

scholarly journals Experimental analysis of steel fiber reinforced concrete beams in shear

2022 ◽  
Vol 15 (3) ◽  
Author(s):  
Aaron Kadima Lukanu Lwa Nzambi ◽  
Dênio Ramam Carvalho de Oliveira ◽  
Marcus Vinicius dos Santos Monteiro ◽  
Luiz Felipe Albuquerque da Silva
Keyword(s):  
Shear Strength ◽  
Reinforced Concrete ◽  
Steel Fiber ◽  
Concrete Beams ◽  
Reinforcement Ratio ◽  
Steel Fibers ◽  
Reinforced Concrete Beams ◽  
Experimental Program ◽  
Longitudinal Reinforcement ◽  
Fiber Addition

Abstract Some normative recommendations are conservative in relation to the shear strength of reinforced concrete beams, not directly considering the longitudinal reinforcement rate. An experimental program containing 8 beams of (100 x 250) mm2 and a length of 1,200 mm was carried out. The concrete compression strength was 20 MPa with and without 1.00% of steel fiber addition, without stirrups and varying the longitudinal reinforcement ratio. Comparisons between experimental failure loads and main design codes estimates were assessed. The results showed that the increase of the longitudinal reinforcement ratio from 0.87% to 2.14% in beams without steel fiber led to an improvement of 59% in shear strength caused by the dowel effect, while the corresponding improvement was of only 22% in fibered concrete beams. A maximum gain of 109% in shear strength was observed with the addition of 1% of steel fibers comparing beams with the same longitudinal reinforcement ratio (1.2%). A significant amount of shear strength was provided by the inclusion of the steel fibers and allowed controlling the propagation of cracks by the effect of stress transfer bridges, transforming the brittle shear mechanism into a ductile flexural one. From this, it is clear the shear benefit of the steel fiber addition when associated to the longitudinal reinforcement and optimal values for this relationship would improve results.

scholarly journals THE EFFECT OF FILLER CONTENT ON MECHANICAL PROPERTIES OF POLYPROPYLENE/CLAY NANOCOMPOSITES

2016 ◽  
Vol 5 (1) ◽  
Author(s):  
Teuku Rihayat ◽  
Noor Mustafa ◽  
Saari Mustapha
Keyword(s):  
Mechanical Properties ◽  
Tensile Test ◽  
Modulus Of Elasticity ◽  
Maximum Stress ◽  
Filler Content ◽  
Clay Nanocomposites ◽  
Stress Strain

This study investigates the effect of filler content on mechanical properties for polypropylene. There are  synthesis clay and  un-synthesis clay  used  as  filler  content. Different ratio  of  clay  was  d  in polypropylene to study which ratio have a better mechanical properties. The tensile test was carried out using INSTRON5565 and the maximum stress, strain, and modulus of elasticity observed. Results of the study showed that polypropylene/clay nanocomposite has a higher maximum stress compare to pure polypropylene and un-synthesis clay have a lowest. Besides that modulus of elasticity of specimen calculated and finds that it increased with increment filler content and strain did not affect by filler. The conclusion is synthesis clay filled into polypropylene will having a better material.Keywords: Nanocomposite, polypropylene, synthesis clay.

scholarly journals Flexural Behavior of Simply Supported Beams Consisting of Gradient Concrete and GFRP Bars

2021 ◽  
Vol 8 ◽  
Author(s):  
Jing Ji ◽  
Runbao Zhang ◽  
Chenyu Yu ◽  
Lingjie He ◽  
Hongguo Ren ◽  
...  
Keyword(s):  
Bearing Capacity ◽  
Constitutive Models ◽  
Reinforcement Ratio ◽  
Parameter Analysis ◽  
Flexural Behavior ◽  
Statistical Regression ◽  
Simply Supported ◽  
Gfrp Bars ◽  
Flexural Bearing Capacity ◽  
Gfrp Reinforcement

In order to study the flexural behavior of simply supported beams consisting of gradient concrete and GFRP bars, 28 simply supported beams were designed. The main parameters included the strength grades of high-strength concrete (HSC), GFRP reinforcement ratio, and sectional height of HSC. Based on nonlinear constitutive models of materials, meanwhile, considering the bond slip between concrete and GFRP bars, five simply supported beams with gradient concrete and five simply supported beams with GFRP bars were simulated, respectively. Then the mid-span load–displacement curves of beams were obtained. By comparing with the experimental data, the rationality of material constitutive models and finite element modeling was verified. Based on this, the parameter analysis of the beams with GFRP bars and gradient concrete was carried out, and the failure modes of the beams were obtained through investigation. The results show that the failure process of the beams can be divided into two stages: elastic stage and working stage with cracks. With the increase of GFRP reinforcement ratio, the flexural bearing capacity of the beams does not change significantly, while their stiffness increases gradually. The flexural bearing capacity of the beams can be significantly improved by appropriately increasing the strength and sectional height of HSC. The ultimate bearing capacity of the beams is 40% higher than that of the GFRP concrete beams. Finally, based on the plane-section assumption, the calculation formula of normal-section flexural bearing capacity of this kind of beams is proposed through statistical regression method.

scholarly journals Effect of introduction of fullerene soot on mechanical properties of unidirectional thermoplastic tape

2018 ◽  
Vol 245 ◽  
pp. 04011 ◽  
Author(s):  
Ilya Kobykhno ◽  
Dmytro Honcharenko ◽  
Vladimir Yadykin ◽  
Oleg Stolyarov ◽  
Oleg Tolochko
Keyword(s):  
Mechanical Properties ◽  
Composite Materials ◽  
Carbon Fibers ◽  
Modulus Of Elasticity ◽  
Hot Pressing ◽  
Bending Test ◽  
Transverse Reinforcement ◽  
Fullerene Soot

A series of unidirectional thermoplastic tapes (UD tapes) specimens based on carbon fibers and polyamide filled with fullerene soot in a concentration of up to 4 wt. % was made. From the obtained tapes by the method of hot pressing, composite materials (CM) specimens with 0/0 and 90/90 ply orientations were made. A study of the mechanical properties of the samples obtained by the 3-point bending test was made. Shown that the introduction of fullerene soot up to 2 wt. % can significantly increase the strength and modulus of elasticity of both longitudinal and transverse reinforcement directions. Further increase in the concentration of soot leads to a decrease in properties. A theory that describes the effect of fullerene soot on the properties of CM, including the increase and further decrease in properties, depending on the concentration of nanoparticles was proposed.

scholarly journals Temperature Effect on the Compressive Behavior and Constitutive Model of Plain Hardened Concrete

Materials ◽  
2020 ◽  
Vol 13 (12) ◽  
pp. 2801 ◽  
Author(s):  
Ayman El-Zohairy ◽  
Hunter Hammontree ◽  
Eddie Oh ◽  
Perry Moler
Keyword(s):  
Experimental Data ◽  
Compressive Strength ◽  
Temperature Effect ◽  
Modulus Of Elasticity ◽  
Constitutive Models ◽  
Ultimate Strain ◽  
Effect Of Temperature ◽  
Hardened Concrete ◽  
Compressive Behavior ◽  
Stress Strain

Concrete is one of the most common and versatile construction materials and has been used under a wide range of environmental conditions. Temperature is one of them, which significantly affects the performance of concrete, and therefore, a careful evaluation of the effect of temperature on concrete cannot be overemphasized. In this study, an overview of the temperature effect on the compressive behavior of plain hardened concrete is experimentally provided. Concrete cylinders were prepared, cured, and stored under different temperature conditions to be tested under compression. The stress–strain curve, mode of failure, compressive strength, ultimate strain, and modulus of elasticity of concrete were evaluated between the ages of 7 and 90 days. The experimental results were used to propose constitutive models to predict the mechanical properties of concrete under the effect of temperature. Moreover, previous constitutive models were examined to capture the stress–strain relationships of concrete under the effect of temperature. Based on the experimental data and the proposed models, concrete lost 10–20% of its original compressive strength when heated to 100 °C and 30–40% at 260 °C. The previous constitutive models for stress–strain relationships of concrete at normal temperatures can be used to capture these relationships under the effect of temperature by using the compressive strength, ultimate strain, and modulus of elasticity affected by temperature. The effect of temperature on the modulus of elasticity of concrete was considered in the ACI 318-14 equation by using the compressive strength affected by temperature and the results showed good agreement with the experimental data.

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