scholarly journals Stress-Strain Relationship of Ca(OH)2-Activated Hwangtoh Concrete

2014 ◽  
Vol 2014 ◽  
pp. 1-9
Author(s):  
Keun-Hyeok Yang ◽  
Ju-Hyun Mun ◽  
Hey-Zoo Hwang
Keyword(s):  
Compressive Strength ◽  
Strain Curve ◽  
Peak Stress ◽  
Actual Behavior ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Strain Relationship ◽  
Relationship Of ◽  
Strain Model

This study examined the stress-strain behavior of 10 calcium hydroxide (Ca(OH)2)-activated Hwangtoh concrete mixes. The volumetric ratio of the coarse aggregate (Vagg) and the water-to-binder (W/B) ratio were selected as the main test variables. TwoW/Bratios (25% and 40%) were used and the value ofVaggvaried between 0% and 40.0%, and 0% and 46.5% forW/Bratios of 25% and 40%, respectively. The test results demonstrated that the slope of the ascending branch of the stress-strain curve of Ca(OH)2-activated Hwangtoh concrete was smaller, and it displayed a steeper drop in stress in the descending branch, compared with those of ordinary Portland cement (OPC) concrete with the same compressive strength. This trend was more pronounced with the increase in theW/Bratio and decrease inVagg. Based on the experimental observations, a simple and rational stress-strain model was established mathematically. Furthermore, the modulus of elasticity and strain at peak stress of the Ca(OH)2-activated Hwangtoh concrete were formulated as a function of its compressive strength andVagg. The proposed stress-strain model predicted the actual behavior accurately, whereas the previous models formulated using OPC concrete data were limited in their applicability to Ca(OH)2-activated Hwangtoh concrete.

scholarly journals A Stress-Strain Model for Brick Prism under Uniaxial Compression

2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Keun-Hyeok Yang ◽  
Yongjei Lee ◽  
Yong-Ha Hwang
Keyword(s):  
Strain Curve ◽  
Peak Stress ◽  
Test Results ◽  
Compression Tests ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
Proposed Model ◽  
Relationship Model ◽  
Strain Relationship ◽  
Strain Model

This study proposes a simple and rational stress-strain relationship model applicable to brick masonry under compression. The brick prism compression tests were conducted with different mortar strengths and with constant brick strength. From the observation of the test results, shape of the stress-strain curve is assumed to be parabola. In developing the stress-strain model, the modulus of elasticity, the strain at peak stress, and the strain at 50% of the peak stress on the descending branch were formulated from regression analysis using test data. Numerical and statistical analyses were then performed to derive equations for the key parameter to determine the slopes at the ascending and descending branches of the stress-strain curve shape. The reliability of the proposed model was examined by comparisons with actual stress-strain curves obtained from the tests and the existing model. The proposed model in this study turned out to be more accurate and easier to handle than previous models so that it is expected to contribute towards the mathematical simplicity of analytical modeling.

scholarly journals Stress-strain model for grade 275 reinforcing steel with cyclic loading

1978 ◽  
Vol 11 (2) ◽  
pp. 101-109 ◽  
Author(s):  
K. J. Thompson ◽  
R. Park
Keyword(s):  
Axial Loading ◽  
Strain Curve ◽  
Cyclic Stress ◽  
Stress Strain ◽  
Reinforcing Bar ◽  
Strain Behaviour ◽  
Strain Relationship ◽  
Reversed Loading ◽  
Relationship Of ◽  
Strain Model

The stress-strain relationship of Grade 275 steel reinforcing bar under cyclic (reversed) loading is examined using experimental results obtained previously from eleven test specimens to which a variety of axial loading cycles has been applied. A Ramberg-Osgood function is fitted to the experimental stress-strain curves to follow the cyclic stress-strain behaviour after the first load run in the plastic range. The empirical constants in the function are determined by regression analysis and are found to depend mainly on the plastic strain imposed
in the previous loading run. The monotonic stress-strain curve for the steel, with origin of strains suitably adjusted, is assumed to be the envelope curve giving the upper limit of stress. The resulting Ramberg-Osgood expression and envelope is found to give good agreement with the experimentally measured cyclic stress-strain curves.

Analysis of the Mechanic Behavior and Rutting of Asphalt Concrete Using a Sand Model

1999 ◽  
Vol 15 (4) ◽  
pp. 177-184
Author(s):  
Ming-Lou Liu
Keyword(s):  
Asphalt Concrete ◽  
Stress Path ◽  
Plasticity Model ◽  
Test Results ◽  
Research Subjects ◽  
Stress Strain ◽  
Strain Behavior ◽  
Strain Relationship ◽  
Concrete Materials ◽  
Relationship Of

AbstractThe stress-strain relationship of the sand and asphalt concrete materials is one of the most important research subjects in the past, and many conctitutive laws for these materials have been proposed in the last two decades. In this study, the Vermeer plasticity model is modified and used to predict the behavior of the sand and asphalt concrete materials under different stress path conditions. The results show that the predictions and test results agree well under different stress path conditions. However, the orignal Vermeer model can not predict the stress-strain behavior of the asphalt concrete. Finally, the modified Vermeer plasticity model is incorporated with the pavement rutting model to predict the rut depth of pavement structure under traffic loadings.

Stress-Strain Model for Confined Concrete in Cross-Shaped Columns

2012 ◽  
Vol 450-451 ◽  
pp. 822-826
Author(s):  
Lin Zhu Sun ◽  
Tie Cheng Wang ◽  
Fang Yang
Keyword(s):  
Strain Curve ◽  
Peak Stress ◽  
Confined Concrete ◽  
Peak Strain ◽  
Test Results ◽  
Stress Strain Curve ◽  
Stress Strain ◽  
The Cross ◽  
Strain Model ◽  
Variation Rule

To establish complete stress-strain curve equations for confined concrete in cross-shaped columns, we designed 7 test specimens corresponding to the usable eigenvalue range of stirrup of the cross-shaped columns. We obtained the test results of the reinforced concrete cross-shaped columns through axial compression test, got the system parameters of a stress-strain model through statistical analysis of the test data, and then established stress-strain curves for confined concrete in the cross-shaped columns. This model reflects the variation rule of the stress-strain curve of confined concrete in cross-shaped columns. Compared with the stress-strain model for confined concrete in square columns, the confined concrete in cross-shaped columns has smaller peak stress, larger peak strain, and relatively steeper descending part of curve. The research results provide theorotical basis for nonlinear analysis of cross-shaped columns.

scholarly journals A Stress-Strain Model for Unconfined Concrete in Compression considering the Size Effect

2019 ◽  
Vol 2019 ◽  
pp. 1-13
Author(s):  
Keun-Hyeok Yang ◽  
Yongjei Lee ◽  
Ju-Hyun Mun
Keyword(s):  
Compressive Strength ◽  
Aspect Ratio ◽  
Size Effect ◽  
Maximum Stress ◽  
Damage Zone ◽  
Peak Stress ◽  
Equivalent Diameter ◽  
Stress Strain ◽  
Compressive Strength Of Concrete ◽  
Strain Model

In this study, a stress-strain model for unconfined concrete with the consideration of the size effect was proposed. The compressive strength model that is based on the function of specimen width and aspect ratio was used for determining the maximum stress. In addition, in stress-strain relationship, a strain at the maximum stress was formulated as a function of compressive strength considering the size effect using the nonlinear regression analysis of data records compiled from a wide variety of specimens. The descending branch after the maximum stress was formulated with the consideration of the effect of decreasing area of fracture energy with the increase in equivalent diameter and aspect ratio of the specimen in the compression damage zone (CDZ) model. The key parameter for the slope of the descending branch was formulated as a function of equivalent diameter and aspect ratio of the specimen, concrete density, and compressive strength of concrete. Consequently, a rational stress-strain model for unconfined concrete was proposed. This model reflects trends that the maximum stress and strain at the peak stress decrease and the slope of the descending branch increases, when the equivalent diameter and aspect ratio of the specimen increase. The proposed model agrees well with the test results, irrespective of the compressive strength of concrete, concrete type, equivalent diameter, and aspect ratio of the specimen.

Effect Analysis of Temperature on the Rubber Material Stress-Strain Relationship

2014 ◽  
Vol 977 ◽  
pp. 116-119 ◽  
Author(s):  
Yu Liang Yang ◽  
Liang Qiao ◽  
Cong Wang ◽  
Fei Lu ◽  
Xiao Hui Kang
Keyword(s):  
Environmental Temperature ◽  
Testing Machine ◽  
Test Results ◽  
Stress Strain ◽  
Rubber Material ◽  
Effect Analysis ◽  
Universal Testing ◽  
Different Temperatures ◽  
Strain Relationship ◽  
Relationship Of

For the effect of environmental temperature on the rubber material stress-strain relationships, rubber tensile specimens, compression specimens and shear specimens were made. Through the electronic universal testing machine Instron 5500R, the stress-strain curves of three kinds of specimens at different temperatures were obtained. The test results showed that the stress-strain relationship of rubber material was typically nonlinear. As the temperature increased, the elastic modulus of rubber material decreased.

Flexural Behavior of Prestressed UHPC Beams

2011 ◽  
Vol 243-249 ◽  
pp. 1145-1155
Author(s):  
Jian Yang ◽  
Zhi Fang ◽  
Gong Lian Dai
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
Strain Curve ◽  
Flexural Behavior ◽  
Experimental Program ◽  
Ultra High Performance Concrete ◽  
Stress Strain ◽  
Flexural Response ◽  
Strain Relationship ◽  
Relationship Of

Ultra High Performance Concrete (UHPC), which has very special properties that are remarkably different to the properties of normal and high performance concrete, is being increasingly used for the construction of structure. In this paper, an experimental program was formulated to investigate the characteristics of complete stress-strain curve of UHPC in uniaxial compression and flexural behaviors of prestressed UHPC beams. The particular focus was the influence of the partial prestress ratio and jacking stress on the flexural response of UHPC beams. The results show that UHPC is of good deformability, and a general form of the serpentine curve is proposed to represent the complete stress-strain relationship of UHPC in compression. The tests of beams demonstrated that the UHPC beams have an excellent behavior in load carrying capacity, crack distribution and deformability, their ultimate deflection can reach 1/34～1/70 of the span. Based on this investigation, theoretical correlations for the prediction structure response of UHPC beam are proposed.

scholarly journals Stress-Strain Behavior of Cementitious Materials with Different Sizes

2014 ◽  
Vol 2014 ◽  
pp. 1-11 ◽  
Author(s):  
Jikai Zhou ◽  
Pingping Qian ◽  
Xudong Chen
Keyword(s):  
Flexural Strength ◽  
Size Effect ◽  
Cement Mortar ◽  
Strain Curve ◽  
Cementitious Materials ◽  
Test Results ◽  
Stress Strain ◽  
Strain Behavior ◽  
Modified Equation ◽  
Good Agreement

The size dependence of flexural properties of cement mortar and concrete beams is investigated. Bazant’s size effect law and modified size effect law by Kim and Eo give a very good fit to the flexural strength of both cement mortar and concrete. As observed in the test results, a strong size effect in flexural strength is found in cement mortar than in concrete. A modification has been suggested to Li’s equation for describing the stress-strain curve of cement mortar and concrete by incorporating two different correction factors, the factors contained in the modified equation being established empirically as a function of specimen size. A comparison of the predictions of this equation with test data generated in this study shows good agreement.

Laboratory Evaluation of the Stress-Strain relationship of Permeable Concrete

2011 ◽  
Vol 243-249 ◽  
pp. 3259-3262 ◽  
Author(s):  
Manal Hussin ◽  
Zhu Ge Yan ◽  
Frank Bullen ◽  
Weena Lokuge
Keyword(s):  
Pore Space ◽  
Strain Curve ◽  
Laboratory Evaluation ◽  
Fine Aggregate ◽  
Stress Strain ◽  
Average Pore ◽  
Water To Cement Ratio ◽  
Strain Relationship ◽  
New Type ◽  
Relationship Of

The authors conducted research aimed at developing a new type of permeable concrete material with enhanced structural strength. This paper presents and discusses the results of their investigation on the unaxial compressive stress-strain relationship of porous concrete made with two different mix designs with constant water to cement ratio. The concrete mixes were designed with a target compressive strength between 15-25 MPa and target porosity between 10-15% to study the effect of pore sizes on the stress-strain curve. The average pore space was increased by increasing the relative amount of large aggregate. The reduction in the relative amount of fine aggregate increased the average pore space and resulted in a reduction in mix stiffness and a marginal increase in ultimate strength.

Study on Stress-Strain Relationship of FRP-Confined Concrete Filled Steel Tubes

2010 ◽  
Vol 163-167 ◽  
pp. 3826-3829
Author(s):  
Feng Yu ◽  
Ping Wu
Keyword(s):  
Main Parameter ◽  
Steel Tube ◽  
Confined Concrete ◽  
Stress Strain ◽  
Steel Tubes ◽  
Concrete Filled Steel Tube ◽  
Strain Relationship ◽  
Relationship Of ◽  
Concrete Filled Steel Tubes ◽  
Strain Model

FRP-confined concrete filled steel tube may fully use the character of FRP-confined concrete and concrete filled steel tube. Based on the analysis of existing experimental data, the formula of ultimate bearing capacity of FRP-confined concrete filled steel tube is proposed. The mechanical behavior of FRP-confined concrete filled steel tube is mainly related to the equivalent confinement effect coefficient before the rupture of FRP. Based on the static equilibrium condition, the equivalent conversion section is adopted; taking as main parameter, the simplified stress-strain model of FRP-confined concrete filled steel tube is established. The predictions of the model agree well with test data.

Sign in / Sign up

Export Citation Format

Share Document