Reliability of Ultrasonic Pulse Velocity Method for Determining Dynamic Modulus of Asphalt Mixtures

2017 ◽  
Vol 4 (9) ◽  
pp. 9709-9712 ◽  
Author(s):  
Debanjan Majhi ◽  
Sandip Karmakar ◽  
Tapas Kumar Roy
2011 ◽  
Vol 243-249 ◽  
pp. 165-169 ◽  
Author(s):  
Iqbal Khan Mohammad

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.


2021 ◽  
Vol 21 (6) ◽  
pp. 209-215
Author(s):  
Yunje Lee ◽  
Jaehun Ahn ◽  
Yungtak Oh ◽  
Jaegeon Lee

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.


2019 ◽  
Vol 292 ◽  
pp. 29-33
Author(s):  
Dalibor Kocáb ◽  
Petr Daněk ◽  
Petr Žítt ◽  
Aleš Tichý ◽  
Martin Alexa

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.


2021 ◽  
Vol 71 (343) ◽  
pp. e257
Author(s):  
D. Castillo ◽  
S. Hedjazi

Due to the increasing use of rapid construction methods and the challenges of maintaining construction schedules, a growing demand exists for procedures that can assure quality of work without sacrificing the pace of construction. The quality control of construction materials specifically, the mechanical properties of concrete are among the most important concerns in today’s construction industry. In the present study, the correlation between fiber-reinforced concrete’s compressive strength and dynamic modulus to its ultrasonic pulse velocity is investigated at early ages up to 7 days after mixing. An experimental program involving 189 FRC specimens were designed containing different types of structural fibers, fiber volume fractions, and water-to-cement ratios. Mathematical equations were developed to predict the early-age compressive strength and dynamic modulus of four different types of fiber-reinforced concrete based on ultrasonic pulse velocity. The predicted compressive strength and dynamic modulus from the proposed equations showed good agreement with the measured ones.


Materials ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 938 ◽  
Author(s):  
Miguel Bravo ◽  
Javier A. Forero ◽  
José Nobre ◽  
Jorge de Brito ◽  
Luís Evangelista

This paper intends to analyze the performance of mortars with reactive MgO, as a sustainable alternative to cement. Six different MgOs from Australia, Canada, and Spain were used in the production of mortars as partial substitutes for cement, namely 5%, 10%, 15%, 20%, and 25% (by weight). MgOs with different levels of reactivity were used to analyze its influence on the performance of MgO mortars. In order to evaluate the mechanical performance of these mortars, compressive strength, flexural strength, dynamic modulus of elasticity, and ultrasonic pulse velocity tests were performed. Compressive strength tests showed that the use of 25% reactive MgO can cause a decrease of this property of between 28% and 49%. The use of reactive MgO affected the other mechanical properties less. This paper also intends to analyze the durability performance of mortars with reactive MgO. To that effect, water absorption by capillarity was assessed. In this research, the effect of using MgO on the shrinkage was also analyzed. It was found that shrinkage may decrease by more than a half in some cases.


2021 ◽  
Vol 20 (1) ◽  
pp. 52-61
Author(s):  
Harun TANYILDIZI ◽  

The mechanical properties of polymer impregnated concrete containing polypropylene fiber were statistically and experimentally examined in this study. Taguchi L9 (33) was used in this study. The variables used for experiments were selected as the polypropylene fiber ratio (0%, 1% and 2%), cement dosage (300, 350 and 400 kg/m3) and curing time (7, 14 and 28 days). After the specimens were cured at the specified curing times, they were dried at 105 ±5 °C. Then, the monomer was impregnated to the specimens for 24 hours under atmospheric conditions. The samples for the polymerization of monomer was kept within the drying oven at 60 °C for 6 hours. The compressive strength and ultrasonic pulse velocity tests of specimens, in which polymerization was applied, was conducted. Furthermore, the dynamic modulus of elasticity of samples was calculated using the ultrasonic pulse velocity. The Taguchi analysis found that the best values for the ultrasonic pulse velocity, dynamic modulus of elasticity and compressive strength were 28 days for curing, 1% for the polypropylene fiber percentage and 400 kg/m3 for the cement dosage. The Anova analysis found that the polypropylene fiber percentage had the biggest effect on the mechanical properties of polymer impregnated concrete containing polypropylene fiber.


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