Observation of the Development of the Elastic Modulus and Strength in a Polymer-Cement Mortar Using the Acoustic Emission Method

2018 ◽  
Vol 272 ◽  
pp. 76-81
Author(s):  
Dalibor Kocáb ◽  
Libor Topolář ◽  
Barbara Kucharczyková ◽  
Petr Pőssl ◽  
Michaela Hoduláková
Keyword(s):  
Compressive Strength ◽  
Acoustic Emission ◽  
Elastic Modulus ◽  
Modulus Of Elasticity ◽  
Cement Mortar ◽  
Resonance Method ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Acoustic Emission Method ◽  
Emission Method

The paper describes an experiment focused on observing the development of the elastic modulus and compressive strength in a polymer-cement mortar during the first 28 days of aging. The specimens (aged 3 and 28 days) were tested for the static and dynamic modulus of elasticity using two methods – the ultrasonic pulse velocity test and the resonance method. During the test of the modulus of elasticity in compression the mortar’s behaviour was also examined by means of the acoustic emission method, which is based on the recording of mechanical pulses caused by dilation waves generated by microcracks that form during loading. The outcome of the experiment is an evaluation of the polymer-cement mortar’s behaviour in terms of the development of its elastic modulus and compressive strength as well as in terms of the material’s acoustic response during loading.

Non-Destructive Testing for Concrete: Dynamic Modulus and Ultrasonic Velocity Measurements

2011 ◽  
Vol 243-249 ◽  
pp. 165-169 ◽  
Author(s):  
Iqbal Khan Mohammad
Keyword(s):  
Compressive Strength ◽  
Modulus Of Elasticity ◽  
Dynamic Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Non Destructive Testing ◽  
Destructive Testing ◽  
Dynamic Modulus Of Elasticity ◽  
Non Destructive

Nondestructive testing (NDT) is a technique to determine the integrity of a material, component or structure. The commonly NDT methods used for the concrete are dynamic modulus of elasticity and ultrasonic pulse velocity. The dynamic modulus of elasticity of concrete is related to the structural stiffness and deformation process of concrete structures, and is highly sensitive to the cracking. The velocity of ultrasonic pulses travelling in a solid material depends on the density and elastic properties of that material. Non-destructive testing namely, dynamic modulus of elasticity and ultrasonic pulse velocity was measured for high strength concrete incorporating cementitious composites. Results of dynamic modulus of elasticity and ultrasonic pulse velocity are reported and their relationships with compressive strength are presented. It has been found that NDT is reasonably good and reliable tool to measure the property of concrete which also gives the fair indication of the compressive strength development.

The Assessment of High-Temperature Degraded Concrete Specimens of Different Mixtures by Acoustic Emission Method during Three-Point Bending Test and Pulse Velocity Method in Comparison with Destructive Tests

2017 ◽  
Vol 908 ◽  
pp. 88-93 ◽  
Author(s):  
Libor Topolář ◽  
Richard Dvořák ◽  
Luboš Pazdera
Keyword(s):  
Acoustic Emission ◽  
Building Materials ◽  
Pulse Velocity ◽  
Bending Test ◽  
Structural Components ◽  
Acoustic Emission Method ◽  
Emission Method ◽  
Three Point Bending ◽  
Live Loads ◽  
Non Destructive

One of the advantages of concrete over other building materials is its inherent fire-resistive properties. The concrete structural components still must be able to withstand dead and live loads without collapse even though the rise in temperature causes a decrease in the strength and modulus of elasticity for concrete and steel reinforcement. In addition, fully developed fires cause expansion of structural components and the resulting stresses and strains must be resisted. This paper reports the results of measurements by Acoustic Emission method during three-point bending test on concrete specimens. The Acoustic emission method is a non-destructive technique used widely for structural health monitoring purposes of structures. The sensors are mounted by beeswax on the surface of the material or structure to record the motion of the surface under the elastic excitation of the cracking sources. The concrete specimens were heated in a programmable laboratory furnace at a heating rate of 5 °C/min. The specimens were loaded at six temperatures, 200 °C, 400 °C, 600 °C, 800 °C, 1000 °C, and 1200 °C maintained for 60 minutes. The results are obtained in the laboratory.

scholarly journals A Study on Tannery Sludge as a Raw Material for Cement Mortar

Materials ◽  
2019 ◽  
Vol 12 (9) ◽  
pp. 1562 ◽  
Author(s):  
Jurgita Malaiškienė ◽  
Olga Kizinievič ◽  
Viktor Kizinievič
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Cement Mortar ◽  
Ultrasonic Pulse Velocity ◽  
Xrd Analysis ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Raw Material ◽  
Tannery Sludge ◽  
Limit Values

The paper analyses the properties (chemical and mineral composition, microstructure, density, etc.) of recycled tannery sludge (TS) and the possibilities for using it in cement mortar mixture. Mortar specimens containing 3–12% of tannery sludge by weight of cement and 3–9% of tannery sludge by weight of sand were tested. Flowability, density, ultrasonic pulse velocity (UPV), flexural and compressive strength, water absorption and sorptivity of the mortar were analysed. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analysis of tannery sludge and mortar are presented. The tests revealed that replacement of 6% of cement with tannery sludge in the mix increased flexural and compressive strength and UPV values, whereas water absorption decreased. SEM and XRD analysis revealed that specimens with tannery sludge contained lower amounts of ettringite and higher amounts of portlandite; the obtained structure was denser and contained more calcium hydrosilicates (C-S-H). Chromium leaching values in cement mortars were found not to exceed the limit values set forth in Directive 2003/33/EC.

scholarly journals EFFECT OF EPOXY ADDITION ON COMPRESSIVE STRENGTH, FLEXURAL AND ULTRASONIC PLUS VELOCITY OF CEMENT MORTAR

2021 ◽  
Vol 25 (Special) ◽  
pp. 2-60-2-64
Author(s):  
Mohmmed J. Mohmmed ◽  
◽  
Khalid M. Owaid ◽  
Raouf M.Raouf ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Cement Mortar ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Different Ages ◽  
Epoxy Content

This study aims to study the compressive strength and ultrasonic pulse velocity of mortar which contains epoxy composed of two parts: resin and hardener, .at 5, 10, 15, and 20 (wt. %) of epoxy content at different ages (7, 28) days. Where the results showed an increase in the value of compressive strength gradually and the highest at 15% of epoxy content (64.6, and 69.4 MPa) at (7, 28) day, respectively.

Possibilities of Experimental Determinations of the Modulus of Elasticity in the early Stage of Ageing of Cement Composites

2018 ◽  
Vol 276 ◽  
pp. 35-40
Author(s):  
Romana Halamová ◽  
Dalibor Kocáb ◽  
Barbara Kucharczyková ◽  
Petr Daněk ◽  
Petr Misák
Keyword(s):  
Modulus Of Elasticity ◽  
Early Stage ◽  
Resonance Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Load Test ◽  
Cement Composites ◽  
Static Load Test

This paper deals with the possibilities of experimental determination of the dynamic and static modulus of elasticity of fine-grained cement composites in the early stage of setting and hardening - up to 72 hours. Several cement pastes and cement mortars were produced for the purpose of this experiment. The measurement of the modulus of elasticity on the manufactured cement-based composites was carried out in the first 24 hours, each time only by the ultrasonic pulse velocity test using the innovative Vikasonic instrument. In the following 48 hours, the resonance method and the static load test were employed. The results of the pilot measurement and particularly the assessment of the possibilities of determination of the moduli of elasticity are presented in this paper.

Influence of a Shrinkage-Reducing Admixture on the Damage to the Internal Structure of Alkali-Activated Composites during Testing of the Modulus of Elasticity

2018 ◽  
Vol 272 ◽  
pp. 28-33
Author(s):  
Dalibor Kocáb ◽  
Vlastimil Bílek Jr. ◽  
Libor Topolář ◽  
Petr Daněk ◽  
Barbara Kucharczyková ◽  
...  
Keyword(s):  
Internal Structure ◽  
Modulus Of Elasticity ◽  
Resonance Method ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Acoustic Activity ◽  
Static Modulus ◽  
Shrinkage Reducing Admixture ◽  
Static Modulus Of Elasticity ◽  
Alkali Activated

This article deals with an experimental determination of the static modulus of elasticity in compression on fine-grained composites based on alkali-activated slag. This experiment included an alkali-activated composite without a shrinkage-reducing admixture and the same composite with a shrinkage-reducing admixture. The test specimens were subjected to testing of the dynamic modulus of elasticity using the ultrasonic pulse velocity test and the resonance method as well as of the static modulus of elasticity in compression. The static modulus of elasticity test was accompanied by the measurement of the acoustic activity of the material using the acoustic emission method, whose advantages is the possibility to detect early formation and propagation of cracks in the internal structure of the material. The output of the described experiment is a detailed evaluation of the differences in the behaviour of the tested alkali-activated composites based on the observed values of the modulus of elasticity and the recorded acoustic activity of the material during loading.

scholarly journals Effect of Hollow Corundum Microspheres Additive on Physical and Mechanical Properties and Thermal Shock Resistance Behavior of Bauxite Based Refractory Castable

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4736
Author(s):  
Rimvydas Stonys ◽  
Jurgita Malaiškienė ◽  
Jelena Škamat ◽  
Valentin Antonovič
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Thermal Shock ◽  
Modulus Of Elasticity ◽  
Thermal Shock Resistance ◽  
Visual Analysis ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Shock Resistance

This paper analyses the effect of hollow corundum microspheres (HCM) on both physical-mechanical properties (density, ultrasonic pulse velocity, modulus of elasticity, and compressive strength) and thermal shock resistance behavior of refractory medium cement castable with bauxite aggregate. Moreover, the scanning electron microscopy (SEM) results of HCM and refractory castable samples are presented in the paper. It was found that the replacement of bauxite of 0–0.1 mm fraction by HCM (2.5%, 5%, and 10% by weight of dry mix) had no significant effect on the density and compressive strength of castable, while the modulus of elasticity decreased by 15%. Ultrasonic pulse velocity (Vup) values and the visual analysis of the samples after thermal cycling showed that a small amount of HCM in composition of refractory castable could reduce the formation and propagation of cracks and thus increase its thermal shock resistance.

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