scholarly journals Tensile Strength and Dynamic Modulus of Pervious Polymer Concrete with Freezing and Thawing Cycles

2021 ◽  
Vol 21 (6) ◽  
pp. 209-215
Author(s):  
Yunje Lee ◽  
Jaehun Ahn ◽  
Yungtak Oh ◽  
Jaegeon Lee
Keyword(s):  
Tensile Strength ◽  
Dynamic Modulus ◽  
Low Impact Development ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Polymer Concrete ◽  
Freezing And Thawing ◽  
Test Standards ◽  
Before And After

The expansion of impervious areas owing to urbanization has adverse effects on water circulation. The application of low-impact development techniques to solve these problems is gaining popularity. Among others, Permeable pavements are the most widely employed low-impact development techniques. In this study, the dynamic modulus and tensile strength of pervious polymer concrete pavement were evaluated before and after freezing-thawing cycles. A tensile strength test, performed to check the soundness of the pervious polymer concrete, yielded a tensile strength and tensile strength ratio of 0.66 to 0.96 MPa, and 72 to 83%, respectively. The ultrasonic pulse velocity was measured to determine the dynamic modulus according to the freezing-thawing cycles. When 300 freezing-thawing cycles were performed, the dynamic modulus was analyzed to drop to a level of 77~85% of the initial value. The standards for freezing and thawing tests of pervious concrete have not yet been established. It is necessary to develop test standards for freezing-thawing resistance of pervious concretes considering climate change.

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.

scholarly journals Attempts to Improve the Subsurface Properties of Horizontally-Formed Cementitious Composites Using Tin(II) Fluoride Nanoparticles

Coatings ◽  
2020 ◽  
Vol 10 (1) ◽  
pp. 83 ◽  
Author(s):  
Kamil Krzywiński ◽  
Łukasz Sadowski ◽  
Jacek Szymanowski ◽  
Andrzej Żak ◽  
Magdalena Piechówka-Mielnik
Keyword(s):  
Tensile Strength ◽  
Compressive Strength ◽  
Abrasion Resistance ◽  
Mechanical Performance ◽  
Reference Sample ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cementitious Composites ◽  
Fluoride Nanoparticles

This article presents studies that were performed in order to improve the subsurface properties of horizontally-formed cementitious composites using tin(II) fluoride nanoparticles. The main aim of the study was to solve the problem of the decrease in subsurface properties caused by mortar bleeding and the segregation of the aggregate along the height of the overlay. The article also aims to highlight the patch grabbing difficulties that occur during the process of forming horizontally-formed cementitious composites. Four specimens were analyzed: one reference sample and three samples modified with the addition of 0.5, 1.0, and 1.5% of tin(II) fluoride nanoparticles in relation to the cement mass. To analyze the mechanical properties of the specimens, non-destructive (ultrasonic pulse velocity) and destructive tests (flexural tensile strength, compressive strength, abrasion resistance, pull-off strength) were performed. It was indicated that due to the addition of the tin(II) fluoride, it was possible to enhance the subsurface tensile strength and abrasion resistance of the tested cementitious composites. To confirm the obtained macroscopic results, the porosity of the subsurface was measured using SEM. It was also shown that the addition of the tin(II) fluoride nanoparticles did not reduce its flexural and compressive strength. The results show that horizontally-formed cementitious composites with the addition of 1.0% of tin(II) fluoride nanoparticles in relation to the cement mass obtained the most effective mechanical performance, especially with regard to subsurface properties.

scholarly journals About frost resistance of the contact zone of dry adhesive mixes classes C1 and C2

2020 ◽  
Vol 157 ◽  
pp. 06027
Author(s):  
Grigory Nesvetaev ◽  
Anna Dolgova ◽  
Alexey Revyakin
Keyword(s):  
Contact Zone ◽  
Frost Resistance ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Freezing And Thawing ◽  
Concrete Base ◽  
Dry Adhesives ◽  
Low Modulus ◽  
Redispersible Polymer Powder

The purpose of the study: to identify the effect of the dose of redispersible polymer powders and the type of low-modulus inclusions on the frost resistance of dry adhesives mixes made using Portland cement with the concrete base. Methods of research: The research was carried out on the basis of 75 freezing-thawing cycles. The following parameters were determined: compressive and flexural strength on samples 40x40x160 mm in accordance with GOST 30744; bond strength to the concrete base after 28 days hardening and after 75 cycles of freezing and thawing in accordance with GOST 31356. The dynamic modulus of elasticity was determined by the value of the ultrasonic pulse velocity on samples of 40x40x160 mm. The influence of prescription factors on the ratio of these values after 75 freeze-thaw cycles relative to the values after 28 days hardening under normal conditions was studied. Main results: The coefficients of frost resistance of the contact zone of the adhesive mortar made using dry mixes after 75 cycles of freezing and thawing exceeds the values of the coefficients of frost resistance according to the criteria of strength or dynamic elastic modulus. Dry adhesives mixes of class C1 with a dosage of redispersible polymer powder from 1 to 3% and an air-entraining admixture after 75 freezing cycles may be corresponded to class C2. The coefficient of variation in the compressive strength of mortar inside a series of samples after 28 days of hardening under normal conditions is not appropriate to consider as an indicator of the homogeneity of the mortar structure, potentially having a high resistance to cyclic freezing-thawing.

scholarly journals Verifying Moisture Damage Impact in Asphalt Concrete with the Aid of Nondestructive Test NDT

2020 ◽  
Vol 12 (1) ◽  
pp. 13-20
Author(s):  
Saad Issa Sarsam ◽  
Nazar Sajad Kadium
Keyword(s):  
Elastic Modulus ◽  
Asphalt Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Moisture Damage ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Coefficient Of Determination ◽  
Before And After ◽  
Base Course ◽  
The Impact

One of the major concerns of pavement durability is its susceptibility to moisture damage. In this investigation, non-destructive test NDT has been implemented to detect the moisture damage issue. Asphalt concrete specimens were prepared using the traditional Marshall method for wearing, binder and asphalt stabilized base course. Specimens were traversed by ultrasound pulse velocity before and after practicing the moisture damage procedure. The variation of dynamic and elastic modulus before and after the moisture damage was considered and related to tensile strength ratio TSR. It was noted that the pulse velocity decline by (11, 11.2 and 16.4) % and the dynamic modulus declines by (28, 6.6 and 28.5) % for asphalt concrete wearing, binder and base courses respectively after moisture damage. The elastic modulus exhibits no significant variation after moisture damage for wearing course while it declines by (9 and 11.7) % for binder and base courses respectively after moisture damage. It was concluded that the elastic and dynamic moduli were unable to clearly distinguish the impact of moisture damage, whereas the Seismic modulus calculated from the Ultrasonic Pulse Velocity test was effective in distinguishing such impact. The linear equation obtained with good coefficient of determination can explain 74 % of the variation in the seismic modulus after moisture damage.

scholarly journals Acoustic non-destructive testing of high temperature degraded concrete with comparison of acoustic impedance

2018 ◽  
Vol 219 ◽  
pp. 03003
Author(s):  
Richard Dvořák ◽  
Zdeněk Chobola ◽  
Ivo Kusák
Keyword(s):  
Tensile Strength ◽  
High Temperature ◽  
Acoustic Impedance ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Destructive Testing ◽  
Impact Echo ◽  
Destructive Measurement ◽  
Non Destructive

The paper is focused on non-destructive measurement of high temperature degraded concrete test specimens of three mixtures different by the use of coarse aggregate. Testing is done by ultrasonicpulse velocitymethod and Impact-Echo method. Non-destructive results are compared with destructive tests. Ultrasonic pulse velocity, dominant resonance frequency and acoustic impedance are discussed and compared with changes in density, cubic compressive strength, and tensile strength of concrete. The paper suggests possible assessment of degraded concrete by the change in acoustic impedance dependent on residual tensile strength.

scholarly journals Influence of Sand Size on Mechanical Properties of Fiber Reinforced Polymer Concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 554-560
Author(s):  
Zainab H. Mahdi ◽  
Baydaa Hussain Maula ◽  
Ahmed S. Ali ◽  
Mass R. Abdulghani
Keyword(s):  
Compressive Strength ◽  
Polypropylene Fiber ◽  
Maximum Size ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Epoxy Adhesive ◽  
Pulse Velocity ◽  
Polymer Concrete ◽  
Groundwater Movement ◽  
Rate Of Increase

AbstractThe deterioration of concrete in places exposed to sulphate salts, chlorides and groundwater movement is a major problem. In this research, polymer concrete was produced by testing four mixtures using different sizes of aggregates with epoxy adhesive and two mixtures were reinforced with polypropylene fibers (0.5 and 1)% by weight of Epoxy in addition to the reference mix consisting of cement and sand. Compressive strength, electrical resistivity, ultrasonic pulse velocity, flexural and porosity testing were performed at ages 7, 14, 28, and 60 days. The highest compressive strength, electrical resistance, ultrasonic pulse velocity and zero porosity for mixture had a maximum size of sand less than 600 microns and more than 150 microns, where the rate of increase (272.9, 635.9, 45.9 and 57.7)% respectively compared to the reference mixture. The results showed also that the highest flexural strength was for the mix reinforced with 1% polypropylene fiber. In addition, the specimens at age 28 day submerged in the diluted solution of sulfuric acid at 5 and 10% for 11 weeks. The results showed that there were no change in the volume and weights of the specimens that were submerged.

Examining the Influence of the Shape, Size, and Type of Test Specimens on the Value of Young's Modulus in Lightweight Concrete

2019 ◽  
Vol 292 ◽  
pp. 29-33
Author(s):  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Petr Žítt ◽  
Aleš Tichý ◽  
Martin Alexa
Keyword(s):  
Elastic Modulus ◽  
Statistical Analysis ◽  
Young’S Modulus ◽  
Dynamic Modulus ◽  
Lightweight Concrete ◽  
Young's Modulus ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity

The paper discusses the results of an experiment that focused on measuring Young's modulus in compression using several different specimens. They were made from lightweight concrete with porous aggregate and differed in shape (cylinder × prism), type (casting × core drilling), and size. Each type category counted a minimum of 6 specimens. The determination of Young's modulus was supplemented by a measurement of the dynamic modulus of elasticity determined by the ultrasonic pulse velocity test. The experiment was concluded by a statistical analysis of the measured values, which focused on the influence of each specimen variety on the value of the elastic modulus.

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