scholarly journals Temperature dependence of dynamic and static modulus of elasticity of lightweight expanded clay aggregate concrete

2021 ◽  
Vol 2094 (4) ◽  
pp. 042052
Author(s):  
M A Medvedev ◽  
A M Cherkasov ◽  
E V Tararushkin
Keyword(s):  
Temperature Dependence ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Lightweight Concrete ◽  
Testing Machine ◽  
Asphalt Mixture ◽  
Aggregate Concrete ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Static Modulus Of Elasticity

Abstract The paper presents experimental research the static and dynamic modulus of elasticity of lightweight expanded clay aggregate concrete with averaged density of 1000 kg/m3. The static and dynamic modulus are obtained depending on the influence of temperature in the range from 5 to 50 °C with a step of 15 °C. The dynamic modulus was determined without pre-compression with a testing machine Asphalt Mixture Performance Tester. Besides the modulus of elasticity of lightweight concrete, the temperature dependence of unconfined compressive strength was also determined. Analysis of experimental data showed that with an increase in temperature, strength and modulus of elasticity slightly decrease, which is typical for concretes. For all cases, the temperature dependence can be characterized according to the linear law. Comparison of the static and dynamic modulus of elasticity showed that the dynamic modulus is 60-74% greater than the static modulus over the entire range of the studied temperatures.

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.

Relativity Analysis between Dynamic and Static Modulus of Elasticity on Different Thickness Wood-Plastic Structural Plates

2011 ◽  
Vol 121-126 ◽  
pp. 4254-4258 ◽  
Author(s):  
Gui Wen Yu ◽  
Ying Cheng Hu ◽  
Ji You Gu
Keyword(s):  
Mechanical Properties ◽  
Nondestructive Testing ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Bending Test ◽  
Three Point Bending ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Static Modulus Of Elasticity ◽  
Different Thickness

The relativity was evaluated between dynamic modulus of elasticity (MOE) and static MOE, in order to assess the potential of using nondestructive testing (NDT) method as a checking tool for mechanical properties of wood-plastic structural plates. The dynamic MOE was evaluated on a FFT system, and the static MOE was determined by three point bending test. All of specimens were made of polyethylene（PE）and poplar flour. A significant correlation between the dynamic MOE and the static MOE was obtained from relativity analysis. These results suggest that the NDT method could be appropriate to estimate the dynamic MOE of specimens with different thickness.

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.

scholarly journals DETERMINATION OF DEFORMATION CHARACTERISTICS OF REINFORCED SOIL BASE BY EXPRESS METHOD USING DYNAMIC DENSITOMETER

2019 ◽  
Vol 10 (2) ◽  
pp. 5-12
Author(s):  
D. A Komarov ◽  
V. I Kleveko
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Reinforced Soil ◽  
Deformation Characteristics ◽  
Express Method ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Static Modulus Of Elasticity ◽  
Express Methods

One way to improve the properties of soils is their reinforcement by different geosynthetic materials. Difficulty an objective assessment of the effectiveness of the use of geosynthetics in construction is its one of the reasons preventing their wider application. Conducting research aimed at studying the work of geosynthetic materials in the construction of foundations and their interaction with the ground, is a very costly and time consuming practice. The tests of reinforced soil structures for transport construction, which are influenced by dynamic loads are particularly complex. Geosynthetics can significantly improve the deformation characteristics of reinforced soil bases. Therefore, the use of different express methods for determination of deformation characteristics of reinforced soil bases is very important. Method using the dynamic densitometer is a new express methods for determining the deformation characteristics of subgrade. «Meter ground dynamic modulus DPG-1.2» was used as an apparatus for determining the dynamic modulus of elasticity Ed on the ground surface Dynamic modulus of elasticity Ed has a correlation dependence with a coefficient of compaction and static modulus of elasticity Est . One application of geosynthetic material in road construction is their use in the construction of temporary roads. Therefore, the construction of temporary road, representing a layer of sand of various thickness on the reinforcing geosynthetic interlayer modeled in this work. The carcass geogrid KS-16 «Rossomaha» production on JSC ««Krasnokamsk Metal Mesh Works» «and geotextile Geospan TN-50 manufactured by Ltd «HEXA-woven materials» were used as reinforcing geosynthetics. This article presents the results of the determination of the static modulus of elasticity Est and dynamic elasticity modulus Ed soil reinforced by geosynthetic material and soil without reinforcement using DPG-1.2 device. As a result of the experiment shows that the modulus values obtained with the express method of using the device-DPG 1.2 are comparable with the values of data obtained by the laboratory method, the measurement error does not exceed 22 %. For backfill thicknesses h = 50 mm use the carcass geogrid KS-16 can increase Est by 23 % and Ed by 14 % compared with the unreinforced base. Using the geotextile Hexa TN-50 can increase Est by 15.5 % and Ed by 11 % compared with the unreinforced base. Increasing the thickness backfill h up to 100 mm is practically not reduce the effectiveness of the reinforcement carcass geogrid KS-16 «Rosomaha» - static modulus E st is increased by 22 % and dynamic modulus Ed by 14 % compared to the unreinforced base. And for the geotextile Hexa TH-50 at h = 100 mm reinforcement efficiency is greatly reduced - the value Est and Ed only increased by 2.5 % compared with the unreinforced base. This is probably caused by a significantly greater rigidity carcass geogrid KS-16 «Rosomaha» Thus DPG-1.2 device allows accurately measure the deformation characteristics of soil bases. The use of specialized carcass geogrids KS-16 «Rossomaha «more effectively in the construction of temporary roads in comparison with universal geosynthetics Hexa TN-50.

Some Dynamic Properties of Rubber

1943 ◽  
Vol 16 (1) ◽  
pp. 136-154 ◽  
Author(s):  
C. O. Harris
Keyword(s):  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Dynamic Properties ◽  
Static Strain ◽  
Static Modulus ◽  
Dynamic Modulus Of Elasticity ◽  
Velocity Coefficient

Abstract The following conclusions apply to rubber of the stock tested when bonded to steel: 1. For cylinders in compression and specimens in shear, the damping can be expressed in terms of a velocity coefficient. The damping decreases with increase of frequency; it increases with increase of static strain. 2. The dynamic modulus of elasticity is slightly larger than the static modulus and is not affected by change of frequency. It increases with increase of static strain for the cylinders and decreases for the shear specimens. 3. For cylinders in compression, both damping and modulus of elasticity are dependent upon the ratio of diameter to length.

The Properties of Fine-Aggregate Concrete with Recycled Cement Powder

2016 ◽  
Vol 677 ◽  
pp. 292-297 ◽  
Author(s):  
Tereza Pavlů ◽  
Magdaléna Šefflová ◽  
Vladimír Hujer
Keyword(s):  
Cement Paste ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Fresh Concrete ◽  
Partial Replacement ◽  
Strength Development ◽  
Fine Aggregate ◽  
Aggregate Concrete ◽  
Cement Powder ◽  
Dynamic Modulus Of Elasticity

The main aim of this contribution is verification of properties of concrete with partial replacement of cement by recycled cement powder originating from waste concrete. The main topic of this article is the study of influence of partial replacement of cement by recycled cement powder (RCP) to the cement paste properties, workability of fresh concrete and strength development and dynamic modulus of elasticity of fine aggregate concrete with partial replacement of cement. The workability of fresh concrete were tested by flow table test. The compressive strength, tensile strength in bending and dynamic modulus of elasticity were tested at the age 7, 14, 28 and 90 days. Partial replacement of cement was 0, 5, 10 and 15 % for all these tests. Mechanical properties were investigated by using cubic and prismatic specimens. The determination of the initial setting time of cement paste were measured by automatic Vicat apparatus for replacement rate of cement 0, 5, 10, 15 and 25 %.

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