Experimental Assessment of the Influence of Multiple Cyclic Loading on Selected Properties of Lightweight Concrete

2019 ◽  
Vol 292 ◽  
pp. 45-49
Author(s):  
Petr Misák ◽  
Dalibor Kocáb ◽  
Martin Alexa ◽  
Barbara Kucharczyková ◽  
Petr Daněk ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cyclic Loading ◽  
Modulus Of Elasticity ◽  
Test Specimen ◽  
Lightweight Concrete ◽  
Test Results ◽  
Static Modulus ◽  
Before And After ◽  
The Difference ◽  
Static Modulus Of Elasticity

The paper deals with results of the experiment when ordinary and lightweight concrete was subjected to cyclic loading. Each test specimen was loaded with the force equivalent to one third of the expected compressive strength value similarly to the static modulus of elasticity test with the difference that the total number of loading cycles was nearly 4500. Dynamic modulus of elasticity and compressive strength was measured before and after cyclic loading. The result of this experiment is statistical analysis of the test results and assessment of the influence of multiple cyclic loading.

scholarly journals Modulus elasticity of the graded concrete, a preliminary research

2018 ◽  
Vol 195 ◽  
pp. 01005 ◽  
Author(s):  
M. Mirza Abdillah Pratama ◽  
B. Sri Umniati ◽  
Bunga Arumsari Mutiara Wulandari ◽  
Ay Lie Han ◽  
Buntara Sthenly Gan ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Elastic Modulus ◽  
Modulus Of Elasticity ◽  
Concrete Strength ◽  
Test Results ◽  
Structural Element ◽  
Concrete Material ◽  
Static Modulus ◽  
Preliminary Research ◽  
Static Modulus Of Elasticity

The elastic modulus of materials plays a role in determining the stiffness of a structural element and its level of serviceability. Previous research indicates that the concrete modulus of elasticity could be improved by combining 2 (two) concrete mixes using a gradual compacting method. In this study, the effect of different concrete strength combinations to the resulting modulus of elasticity is examined. Three types of concrete mixes with a strength of 30 MPa, 40 MPa and 50 MPa are prepared. The graded concrete is moulded in cylindrical concrete casts (150 mm x 300 mm) with the following casting configurations: 30-40 MPa, 30-50 MPa, and 40-50 MPa. The static modulus of elasticity test is performed at an age of 28 days using compressometers in accordance with ASTM C469. The test results show that the modulus of elasticity of the graded concrete is proportionally influenced by the stiffness of the higher and the lower concrete material. Additionally, the resulting compressive strength of the graded concrete is determined by the lower concrete strength.

scholarly journals Influence of Hybrid Fibers on Toughness Behavior of High Strength Flowing Concrete

2011 ◽  
Vol 57 (3) ◽  
pp. 249-260 ◽  
Author(s):  
Eethar Thanon Dawood ◽  
Mahyuddin Ramli
Keyword(s):  
Compressive Strength ◽  
Flexural Strength ◽  
Modulus Of Elasticity ◽  
Hybrid Composite ◽  
High Strength ◽  
Steel Fibers ◽  
Hybrid Fibers ◽  
Static Modulus ◽  
Static Modulus Of Elasticity ◽  
Strength And Toughness

Abstract This study investigates the use of steel fibers and hybrid composite with a total fibers content of 2% on the high strength flowing concrete and determines the density, compressive strength, static modulus of elasticity, flexural strength and toughness indices for the mixes. The results show that the inclusion of more than 0.5% of palm fibers in hybrid fibers mixes reduces the compressive strength. The hybrid fibers can be considered as a promising concept and the replacement of a portion of steel fibers with palm fibers can significantly reduce the density, enhance the flexural strength and toughness. The results also indicates that the use of hybrid fibers (1.5 steel fibers + 0.5% palm fibers) in specimens increases significantly the toughness indices and thus the use of hybrid fibers combinations in reinforced concrete would enhance their flexural toughness & rigidity and enhance their overall performances

Repeatability and Reproducibility of the Static Elastic Modulus of Concrete Measurement

2018 ◽  
Vol 272 ◽  
pp. 214-219
Author(s):  
Petr Misák ◽  
Tomáš Vymazal ◽  
Dalibor Kocáb ◽  
Barbara Kucharczyková
Keyword(s):  
Elastic Modulus ◽  
Statistical Methods ◽  
Modulus Of Elasticity ◽  
Interlaboratory Comparison ◽  
Hardened Concrete ◽  
Test Results ◽  
Static Modulus ◽  
Repeatability And Reproducibility ◽  
Expected Values ◽  
Static Modulus Of Elasticity

In recent years, the static modulus of elasticity is one of the most discussed property of hardened concrete. The aim of this article is to show results of 6 performed experiments focused on test results precision. The measurements were made according to the standards ISO 6784 and ISO 1920-10. More than 20 participants (laboratories) from Europe took part in these experiments. Test results were compared using the statistical methods for interlaboratory comparison. Repeatability and reproducibility, which provide more detailed information about range of expected values of elastic modulus, are the most discussed characteristics in the article.

scholarly journals Effect of Cement Type on the Mechanical Behavior and Permeability of Concrete Subjected to High Temperatures

Materials ◽  
2019 ◽  
Vol 12 (18) ◽  
pp. 3021 ◽  
Author(s):  
Izabela Hager ◽  
Tomasz Tracz ◽  
Marta Choińska ◽  
Katarzyna Mróz
Keyword(s):  
High Temperature ◽  
Modulus Of Elasticity ◽  
Experimental Investigations ◽  
Test Results ◽  
Cement Type ◽  
High Temperature Exposure ◽  
Static Modulus ◽  
Granulated Blast Furnace Slag ◽  
Temperature Exposure ◽  
Static Modulus Of Elasticity

The paper presents experimental investigations concerning the influence of the cement type (CEMI 42.5 R Portland cement and CEMIII/A 42.5 N slag cement—with 53% granulated blast furnace slag) on the mechanical and transport properties of heated concretes. The evolution of properties due to high temperature exposure occurring during a fire was investigated. High temperature exposure produces changes in the transport and mechanical properties of concrete, but the effect of cement type has not been widely studied in the literature. In this paper, concretes were made with two cement types: CEMI and CEMIII, using basalt (B) and riverbed aggregates (RB). The compressive and tensile strength, as well as the static modulus of elasticity and Cembureau permeability, were tested after high temperature exposure to 200, 400, 600, 800, and 1000 °C. The evaluation of damage to the concrete and crack development due to high temperature effects was performed on the basis of the change in the static modulus of elasticity. The test results clearly demonstrated that permeability increases with damage, and it follows an exponential type formula for both types of cement.

scholarly journals Caracterization and Compressive Strength of Biocomposite Hydroxyapatite-Borosilicate with Hight Temperature Sintering

2018 ◽  
Vol 248 ◽  
pp. 01005
Author(s):  
Burmawi ◽  
Novesar Jamarun ◽  
Syukri Arief ◽  
Gunawarman
Keyword(s):  
Compressive Strength ◽  
Bone Graft ◽  
Modulus Of Elasticity ◽  
Test Specimen ◽  
Graft Material ◽  
Test Results ◽  
Bone Graft Material ◽  
Maximum Value

The use of Hydroxyapatite as bone graft material continues to increase. To utilize hydroxyapatite, it is often formed into biocomposite. The formation of hydroxyapatite biocomposite intended to address the fragile hydroxyapatite weaknesses. The added element in the formation of this biocomposite is borosilicate. Mixing of this material is arranged with certain composition using ball miling. To form a test specimen, it was printed with compacting force of 5 KN, 15 KN and 25 KN. Test results Compressive Strength.and XRD showed that addition of borosilicate did not change the compound that is hydroxyapatite, but the intensity of hydroxyapatite tends to decrease with addition of borosilicate amount, this is corroborated by FTIR testing. For visible compressive strength, the maximum value occurs at 75: 25 compositions, ie 45 MPa, 42.9 MPa and 52.3 MPa. This suggests that the addition of borosilicate in biocomposite formation does not alter hydroxyapatite compound and can generally increase the compressive strength and modulus of elasticity to 25% wt% borosilicate addition.

Experimental Analysis of the Development of Compressive Strength, Modulus of Elasticity and Acoustic Emission Parameters of Alkali-Activated Composites

2018 ◽  
Vol 760 ◽  
pp. 266-271
Author(s):  
Dalibor Kocáb ◽  
Libor Topolář ◽  
Vlastimil Bílek Jr. ◽  
Barbara Kucharczyková ◽  
Michaela Hoduláková ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Acoustic Emission ◽  
Modulus Of Elasticity ◽  
Stress Test ◽  
Ultrasonic Pulse ◽  
Static Modulus ◽  
Activated Slag ◽  
Static Modulus Of Elasticity ◽  
Non Destructive ◽  
Alkali Activated

This paper describes an experiment focused on monitoring the development of the modulus of elasticity and the compressive strength of composites that are based on alkali‑activated slag (AAS) during the first 28 days of ageing. The test specimens were tested at the age of 3 and 28 days using two non-destructive methods (ultrasonic pulse and resonance methods) to determine the value of the dynamic modulus of elasticity. Subsequently, the same specimens were used to determine the static modulus of elasticity using compressive stress test, during which the behaviour of the composite was monitored by equipment for recording the acoustic emission in the material. The result of the experiment is the evaluation of the behaviour of the AAS composite in regard to the development of its modulus of elasticity and compressive strength, as well as in regard to the acoustic emission method during loading.

scholarly journals AVALIAÇÃO DE TIPOS DE ONDAS GERADAS POR DOIS MODELOS DE TRANSDUTORES PARA DETERMINAÇÃO DO MÓDULO DE ELASTICIDADE DINÂMICO

FLORESTA ◽  
2010 ◽  
Vol 40 (4) ◽  
Author(s):  
Diego Martins Stangerlin ◽  
Joaquim Carlos Gonçalez ◽  
Raquel Gonçalves ◽  
Elio José Santini ◽  
Leandro Calegari ◽  
...  
Keyword(s):  
Surface Waves ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ultrasonic Method ◽  
Point Contact ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Ultrasonic Equipment ◽  
The Difference ◽  
Static Modulus Of Elasticity

O objetivo deste estudo foi de avaliar os tipos de ondas gerados por dois modelos de transdutores utilizados para determinação do módulo de elasticidade dinâmico por meio de ensaios com ultrassom e correlacioná-los ao módulo de elasticidade estático obtido por compressão paralela às fibras. Para tanto, utilizou-se um aparelho de ultrassom dotado de transdutores faces planas e de pontos secos com freqüência de 50 kHz. A velocidade ultra-sônica foi determinada ao considerar a transmissão da onda ao longo do comprimento de amostras de madeira com dimensões nominais de 5 x 5 x 20 cm. Para avaliar a sensibilidade do método ultra-sonoro e os tipos de ondas gerados pelos respectivos transdutores, as amostras foram ensaiadas destrutivamente à compressão paralela, com determinação do módulo de elasticidade por ambas metodologias. Apesar da diferença de valores absolutos do módulo de elasticidade entre os ensaios de ultrassom com transdutores faces planas, que geraram ondas longitudinais, e os ensaios de compressão paralela, em função da natureza viscoelástica da madeira, verificou-se uma boa correlação entre os dados. Com relação ao uso dos transdutores pontos secos, que geraram ondas de superfície, não foi verificada boa correlação com os ensaios destrutivos.Palavras-chave:  Ondas longitudinais; ondas de superfície; transdutores de faces planas; transdutores de pontos secos; ensaios não-destrutivos. AbstractEvaluation of wavess generated for two models of transducers for determining the dynamic modulus of elasticity. This study aimed to evaluate the types of waves generated for two transducers used for determining the dynamic modulus of elasticity by tests with ultrasound and to correlate them to the static modulus of elasticity obtained by parallel compression. For this study ultrasonic equipment with planes faces and point-contact transducers of 50 kHz was used. The ultrasonic speed was determined considering the transmission of the wave along the length of the samples with nominal dimensions of 5 x 5 x 20 cm. To evaluate the sensitivity of the ultrasonic method and the types of waves generated for the transducers, samples were submitted to destructive conventional parallel compression, with determination of the elasticity modulus for both methodologies. Although the difference of absolute values between tests of ultrasound with transducers planes faces, that generated longitudinal waves, and parallel compression, due to wood viscoelastic nature, there was a good correlation between the obtained data. It was not observed good correlation between the use of point-contact transducers, which generated surface waves, and the destructive tests.Keywords:Longitudinal waves; surface waves; planes faces transducers; point-contact transducers; not-destructive methods.

scholarly journals MECHANICAL PROPERTIES OF STRUCTURAL AERATED LIGHTWEIGHT CONCRETE REINFORCED WITH IRON LATHING WASTE

2021 ◽  
Vol 25 (01) ◽  
pp. 100-108
Author(s):  
Samer S. Abdulhussein ◽  
◽  
Ashraf A. Alfeehan ◽  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Modulus Of Elasticity ◽  
Lightweight Concrete ◽  
Volume Fraction ◽  
Hardened Concrete ◽  
Static Modulus ◽  
Flexural Tensile Strength ◽  
Static Modulus Of Elasticity ◽  
The Impact

Currently, the industry of construction requires finding efficient materials to increase the durability and strength as well as decreasing the concrete structure’s total weight. Therefore, an effort was made in this study for examining the impact of adding waste materials such as the iron lathing waste fibers. Iron lathe wastes have been deformed into twisted strips with a width of (4mm) and sieving size of (4.75-10) mm. The experimental investigation has been achieved with the use of four mixes related to light-weight concretes, involving different volumetric ratios of the iron lathing waste fibers as (0%, 1 %, 1.5 %, and 2 %). With the increase in the volume fraction of the lathing waste fibers from 0% to 2%, the results showed that there were a significant increase and improvement in compressive strength, splitting tensile strength, flexural tensile strength, static modulus of elasticity, and dynamic modulus of elasticity by 12%, 67.5%, 134%, 27%, and 26% respectively. This indicates that the iron waste fibers have an important impact in enhancing the mechanical properties of the hardened concrete through the structural change in the concrete matrix.

Softness, Time of Impact, and Internal Damping of Technical Rubber Mlxtures

1955 ◽  
Vol 28 (1) ◽  
pp. 145-152
Author(s):  
E. Schreuer
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Simple Relation ◽  
Internal Damping ◽  
Hertz Theory ◽  
Impact Tests ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
The Difference ◽  
Static Modulus Of Elasticity

Abstract It is shown that the Hertz theory of impact is applicable to the determination, from softness measurements, of the static modulus of elasticity and from impact tests, of the dynamic modulus of elasticity. A simple relation is then derived which connects the difference of these moduli and the internal damping in impact tests. This relation was checked with the rebound resilience values and proved to be valid for all measurements.

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