scholarly journals Experimental Study on the Compressive Behaviors of Brick Masonry Strengthened with Modified Oyster Shell Ash Mortar

Buildings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 266
Author(s):  
Zhouyi Chen ◽  
Wenyuan Chen ◽  
Chenglin Mai ◽  
Jianguang Shi ◽  
Yiren Xie ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Poor Performance ◽  
Oyster Shell ◽  
Brick Masonry ◽  
Masonry Walls ◽  
Test Results ◽  
Strain Relationship ◽  
Design Requirements ◽  
Relationship Of ◽  
Strengthening Method

Masonry bricks were widely used in construction of the walls in most of Chinese historical buildings. The low strength of lime–clay mortar used in existing historical brick masonry walls has usually led to poor performance such as cracking and collapse during earthquakes. As the composition of modified oyster shell ash mortar (MOSA mortar) with higher strength is similar to that of lime–clay mortar, it can be used to partially replace original lime–clay mortar for historical brick masonry buildings in order to improve their seismic performance. Previous research has proven that this strengthening method for brick masonry is effective in improving shear strength. In this paper, we present further experimental research regarding the compressive behaviors of brick masonry strengthened by replacing mortar with a MOSA mortar. The test results showed that the compressive strength of brick masonry specimens strengthened by the proposed method meets the design requirements. The formula for calculating compressive strength for brick masonry strengthened by replacing mortar was obtained by fitting the test results. The calculated values were consistent with the tested ones. In addition, the stress–strain relationship of tested specimens under axial compression was simulated using the parabolic model.

AE Characterization of Brick Masonry Walls Mechanical Behavior: The Case-Study of Alessandria and Boves Barracks

2019 ◽  
Vol 817 ◽  
pp. 563-570 ◽  
Author(s):  
Nicola Viale ◽  
Federico Accornero ◽  
Giuseppe Lacidogna ◽  
Giulio Ventura
Keyword(s):  
Scale Effects ◽  
Brick Masonry ◽  
Test Method ◽  
Critical Conditions ◽  
Masonry Walls ◽  
Significant Information ◽  
Strain Relationship ◽  
The Difference ◽  
Extent Of Damage ◽  
Relationship Of

IIn the present study, Acoustic Emission (AE) monitoring technique is applied in order to characterize the brick masonry of two important military buildings located in Northern Italy: the barracks of Alessandria and Boves. The internal brick masonry walls of the two barracks object of the study are tested by two double flat-jack systems, in order to analyze the compressive strength of the structural material. Flat-jack testing is a versatile and powerful technique that provides significant information on the mechanical properties of historical constructions. The first applications of this technique on some historical monuments clearly showed its great potential. The flat-jack test method is only slightly destructive, and when double jacks are used, this test works according to the same principle as a standard compressive test. The difference is that it is performed in situ and the load is applied by means of two flat-jacks instead of the loading platens. During the tests, the stress-strain relationship of the masonry is determined by gradually increasing the pressure applied by the flat-jacks in the course of three loading-unloading cycles. Moreover, AE technique is coupled to the flat-jack testing, in order to assess the extent of damage in the masonry texture. Thus, AE technique makes it possible to highlight critical phenomena and fracture mechanics scale effects in the masonry by identifying the critical conditions, not entrusted to an analysis of the loading process (compression or shear), rather depending primarily on the distribution and evolution of crack patterns.

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.

Mechanical Performance Analysis of Steel Beam-Concrete Wall Rigid Joint

2013 ◽  
Vol 639-640 ◽  
pp. 796-802
Author(s):  
Yin Hui Qin ◽  
Wen Ji Liu ◽  
Chao Yang Zhou ◽  
Fu Hua Liu
Keyword(s):  
Performance Analysis ◽  
Mechanical Performance ◽  
Experimental Program ◽  
Steel Beam ◽  
Test Results ◽  
Concrete Wall ◽  
Practical Engineering ◽  
Strain Relationship ◽  
Reversed Loading ◽  
Relationship Of

The beam-column joints play a key role in composite steel and concrete structures. In order to ensure a safe design of a new building and obtain optimum design, an experimental program consisting of the tests of three connections with different connection details under low-cyclic reversed loading, A series of mechanical performance such as the stress-strain relationship of steel beam web, beam flange, connecting plate, bracket web, bracket flange, distributing steel, concealed column in node core area are all analyzed, the results show that in the loading process, steel beam flange and web ,bracket flange produced yield deformation, but the bracket web, distributing steel, concealed column didn’t yield, so the steel beam flange and web, bracket flange must be strengthened in the design. The test results also show that the bracket can be regarded as canlitecver model in practical engineering.

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.

The Relationship of NaOH Molarity, Na2SiO3/NaOH Ratio, Fly Ash/Alkaline Activator Ratio, and Curing Temperature to the Strength of Fly Ash-Based Geopolymer

2011 ◽  
Vol 328-330 ◽  
pp. 1475-1482 ◽  
Author(s):  
M. M. A. Abdullah ◽  
H. Kamarudin ◽  
M. Bnhussain ◽  
I. Khairul Nizar ◽  
A.R. Rafiza ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Construction Industry ◽  
Curing Temperature ◽  
Test Results ◽  
Compression Tests ◽  
Naoh Solution ◽  
Alkaline Activator ◽  
Relationship Of ◽  
The Relationship

Geopolymer, produced by the reaction of fly ash with an alkaline activator (mixture of Na2SiO3 and NaOH solutions), is an alternative to the use of ordinary Portland cement (OPC) in the construction industry. However, there are salient parameters that affecting the compressive strength of geopolymer. In this research, the effects of various NaOH molarities, Na2SiO3/NaOH ratios, fly ash/alkaline activator, and curing temperature to the strength of geopolymer paste fly ash were studied. Tests were carried out on 50 x 50 x 50 mm cube geopolymer specimens. Compression tests were conducted on the seventh day of testing for all samples. The test results revealed that a 12 M NaOH solution produced the highest compressive strength for the geopolymer. The combination mass ratios of fly ash/alkaline activator and Na2SiO3/NaOH of 2.0 and 2.5, respectively, produced the highest compressive strength after seven days. Geopolymer samples cured at 60 °C produced compressive strength as high as 70 MPa.

scholarly journals Flexural Strength of Fly ash Brick Masonry Wall with four different bond

2021 ◽  
Vol 2070 (1) ◽  
pp. 012190
Author(s):  
S Shenbagavalli ◽  
Ramesh Babu Chokkalingam
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Carrying Capacity ◽  
Masonry Wall ◽  
Crack Pattern ◽  
Brick Masonry ◽  
The Other ◽  
Masonry Walls ◽  
Load Carrying Capacity ◽  
Load Carrying

Abstract The strength of the masonry mainly depends on type of bond, types of bricks, compressive strength of the bricks and mortar used. The types of bonds play a major role in the properties of brick masonry wall. The most common types of bond used in practice are English bond, Flemish bond, Stretcher bond and Header bond. A lot of study has been performed on the load-carrying capacity of masonry walls. In this paper, effort has been taken to study the influence of different bonds on the flexural strength of the flyash brick masonry wall. For this wall of size 1m × 0.76m × 0.22m has been casted, cured for 28 days and tested in a loading frame. From the results, it was found the English bond gave higher flexural strength compared to other bonds such as Flemish, Stretcher and Header bond. The flexural strength of English bond was around 45 to 50% higher than the other bonds. The crack pattern at failure was also noted for all the masonry walls.

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.

scholarly journals Strength Characteristics Of Polyurethane (PU) With Modified Sand

2015 ◽  
Vol 773-774 ◽  
pp. 1508-1512 ◽  
Author(s):  
Norbaya Sidek ◽  
K. Mohamed ◽  
I.B.M. Jais ◽  
I.A. Abu Bakar
Keyword(s):  
Compressive Strength ◽  
Ground Improvement ◽  
Chemical Substance ◽  
Microcellular Foam ◽  
Unconfined Compression Test ◽  
Rigid Foam ◽  
Soil Stabilisation ◽  
Strain Relationship ◽  
Relationship Of ◽  
Soil Behaviour

Soil stabilisation is defined as a technique to improve the engineering characteristics in order to improve the parameters such as shear strength, compressibility, density, hydraulic conductivity. There are many techniques that can be used for different purposes by enhancing some aspects of soil behaviour and improve the strength and properties of soil. One of the cheapest techniques is by using Polyurethane grout, which is workable for construction and enhances the performance of soil compressive strength. Polyurethane (PU) foam is non-toxic, having an indefinite life span and non-environment unfriendly. PU is a chemical substance that normally used in polymer industries for instance resilience foam seating, rigid foam insulation panels and microcellular foam seals. In this research, different percentages of PU content are mixed with sand to test the compressive strength of modified sand. The compressive strength of sand is determined by conducting the Unconfined Compression Test (UCT) with the mold samples of 50mm diameter and 100mm height. The test determines the compressive strength and generates the stress-strain relationship of the modified sand. It is shown that the compressive strength of modified sand will gradually increase with an increasing PU content percentage (varying from 10% (20 kPa) – 95% (500 kPa). Conclusively, this research could be used as the benchmark of ground improvement technique.

Strength of Masonry Walls Retrofitted with Epoxy Resin Injection

2011 ◽  
Vol 82 ◽  
pp. 545-550 ◽  
Author(s):  
Hideo Araki ◽  
Akira Yasojima ◽  
Junichi Kagawa
Keyword(s):  
Flexural Strength ◽  
Epoxy Resin ◽  
Seismic Loading ◽  
Masonry Walls ◽  
Brick Wall ◽  
Test Results ◽  
Injection Method ◽  
Resin Injection ◽  
Loading Tests ◽  
Strengthening Method

This paper presents the results of the fundamental loading tests with brick elements strengthened by the epoxy resin injection method. Three types of loading tests were performed to evaluate the effects of epoxy resin injection on compressive, shear, and flexural characteristics. The variables considered in this experiment were the strength of the mortar and the applied axial force. To verify the effects of this strengthening method, seismic loading tests were performed on three brick walls. From the test results, an increase in the strength of the element was observed in each test. However, the strength of the mortar did not affect the shear and flexural strength of the brick elements. We proposed equations to estimate the strength of the elements strengthened by the epoxy resin injection method. Improvements to the seismic performance of the brick wall strengthened with epoxy resin were explicitly confirmed.

STUDY ON STRESS-STRAIN RELATIONSHIP OF LOESS BASED ON TWIN SHEAR UNIFIED DAMAGE CONSTITUTIVE MODEL

2008 ◽  
Vol 22 (31n32) ◽  
pp. 5838-5843
Author(s):  
BO HAN ◽  
HANGZHOU LI ◽  
HONG-JIAN LIAO ◽  
ZHENGHUA XIAO
Keyword(s):  
Stress State ◽  
Constitutive Model ◽  
Triaxial Test ◽  
Test Results ◽  
Stress Strain ◽  
Statistical Probability ◽  
Unified Strength Theory ◽  
Strain Relationship ◽  
Damage Constitutive Model ◽  
Relationship Of

To investigate the change of loess stress state, a series of triaxial shear tests were performed on normal consolidation and over consolidation loess. From the test results, the stress-strain relationships of loess were obtained and discussed. Based on unified strength theory, the statistical damage constitutive equation was obtained under triaxial stress state assuming distribution statistical probability of micro-units strength. Then the proposed formulation was adopted to study on stress-strain constitutive relationships of loess and to simulate consolidation undrained triaxial test and consolidation drained triaxial test for normal consolidated and over-consolidated specimens. Compared between experimental and theoretical results, it was shown that the proposed constitutive model can well describe stress-strain relationship of loess, whatever the characteristic of strain softening or stain hardening.

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