Влияние направления прозвучивания и собственной частоты преобразователей при испытании динасовых кирпичей ультразвуковым импульсным методом

2021 ◽  
pp. 15-23
Author(s):  
Иржи Брожовский ◽  
Ленка Боднарова
Keyword(s):  
Building Materials ◽  
Pulse Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Refractory Materials ◽  
Refractory Bricks ◽  
Silica Refractory ◽  
Measuring Base

Evaluating the quality of refractory materials is one of the important stages of production before these materials are handed over to the customer. One of the required parameters is to evaluate ultrasonic pulse velocity, as determined by measurements performed via the ultrasonic pulse method. Are presents findings on the influence of the direction of transmission and the natural frequency of transducers on ultrasonic pulse method measurements of silica refractory bricks. The findings reveal that the measurement requirements specified in standards for other building materials cannot be fully applied in the case of silica refractory bricks, and the assumption that ultrasonic pulse velocity increases with shorter measuring bases is not confirmed. The highest ultrasonic pulse velocities were measured during transmission across the width of the product, while the lowest velocities were measured over the thickness of the sample. In order to evaluate the quality of silica refractory bricks, it is necessary to unambiguously determine a uniform measuring base for transmission so as to ensure the reproducibility of the measurements performed by different laboratories.

scholarly journals Correlation between Uniaxial Compression Test and Ultrasonic Pulse Rate in Cement with Different Pozzolanic Additions

2021 ◽  
Vol 11 (9) ◽  
pp. 3747
Author(s):  
Leticia Presa ◽  
Jorge L. Costafreda ◽  
Domingo Alfonso Martín
Keyword(s):  
Compression Test ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Uniaxial Compression Test ◽  
Unconfined Compression Test ◽  
Pozzolanic Cement ◽  
The Relationship ◽  
Compression Resistance

This work aims to study the relationship between the compression resistance and velocity from ultrasonic pulses in samples of mortars with 25% of pozzolanic content. Pozzolanic cement is a low-priced sustainable material that can reduce costs and CO2 emissions that are produced in the manufacturing of cement from the calcination of calcium carbonate. Using ultrasonic pulse velocity (UPV) to estimate the compressive resistance of mortars with pozzolanic content reduces costs when evaluating the quality of structures built with this material since it is not required to perform an unconfined compression test. The objective of this study is to establish a correlation in order to estimate the compression resistance of this material from its ultrasonic pulse velocity. For this purpose, we studied a total of 16 cement samples, including those with additions of pozzolanic content with different compositions and a sample without any additions. The results obtained show the mentioned correlation, which establishes a basis for research with a higher number of samples to ascertain if it holds true at greater curing ages.

scholarly journals High Strength Nano Silica Based Concrete

2020 ◽  
Vol 9 (7) ◽  
pp. 1150-1155
Keyword(s):  
Electron Microscope ◽  
High Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Hardened Concrete ◽  
Nano Silica ◽  
Nano Structure ◽  
Transmission Electron

There is a substantial curiosity in academia, the investment community and among manufacturers about the exhilarating opportunities offered by nano materials. Although a lot of applications for nanotechnology remain hypothetical, construction is one area where numerous ‘here and now’ applications have already emerged. While existing use is restricted, the market is likely to approach more than 500 million dollars within ten years. Concrete is most likely exceptional in the construction field, that it is the distinct material exclusive to business and hence, is the recipient of a reasonable quantity of research and development capital from the construction industry. SiO2 (Silica) usually is an integral part of concrete in the normal mix. On the other hand, one of the innovations made by the study of concrete at nano scale level is that particle stuffing in concrete can be enhanced by means of adding nano silica (NS), which results in the densification of the micro and nano structure of cementitious composite resulting in enhanced mechanical properties. In this research paper, the result of a thorough investigational analysis on the utilization of NS in addition to cement so that the strength and quality of concrete can improve has been achieved. The effect of various proportions of NS in concrete has been premeditated to evaluate the properties of NS based hardened concrete according to the standard concrete. The obtained outcomes after testing indicate that the addition of NS together with concrete has improved the mechanical behavior of concrete. The NS blended high strength concrete (HSC) shows a better compressive strength (CS) of 66.00 N/mm2 (MPa) after standard twenty eight days, which is an exceptional development over standard concrete. Each and every mixture containing NS in various proportions gave enhanced outcomes in comparison with the standard predictable concrete. RH (Rebound Hammer), UPV (Ultrasonic Pulse Velocity), SEM (Scanning Electron Microscope) and TEM (Transmission Electron Microscope) examinations further authenticate the above results.

scholarly journals Evaluating Concrete Quality using Nondestructive In-situ Testing Methods

2019 ◽  
pp. 22-40
Author(s):  
Khalid Abdel Naser Abdel Rahim
Keyword(s):  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Initial Surface ◽  
In Situ Testing ◽  
Surface Absorption ◽  
Concrete Quality

This manuscript investigate the quality of concrete using non-destructive in-situ testing.The in-situ testing is a process by which different test are carried out such as rebound hammer, ultrasonic pulse veloc-ity, initial surface absorption test and fig air, to determine thein-situ strength, durability and deterioration, air permeability, concrete quality control andperformance. Additionally, the quality of concrete was researched using test methods with experimental results. Moreover, this research has found that (1) the increase in w/c ra-tioleads to a decrease in compressive strength and ultrasonic pulse velocity. Thus, lower w/cratio gives a bet-ter concrete strength in terms of quality, (2) the quicker the ultrasonic pulse travels through concrete indicates that the concrete is denser, therefore, better quality, (3) the lower initial surface absorption value indicates a better concrete with respect to porosity and (4) the w/c ratio plays an important role in the strength and per-meability of concrete.

Effect of high temperature on the mechanical behavior of cement-bonded wood composite produced with wood waste

2021 ◽  
Vol 7 (1) ◽  
pp. 42
Author(s):  
Mehmet Canbaz ◽  
İlkay Kara ◽  
İlker Bekir Topçu
Keyword(s):  
High Temperature ◽  
Building Materials ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Wood Waste ◽  
Wood Composite ◽  
Secondary Products ◽  
Composite Production ◽  
Materials Used

The increase in the population day by day and urbanization has led to a rapid increase in the construction sector. With the increase in demand in construction, the product types of building materials are increasing. It is seen that wastes are formed during and after the production of the materials used in the building. This highlights studies on waste management and recycling of waste.  After construction activities, wastes are recycled or converted to secondary products. One of these is wood waste, a traditional building material. In addition to the production of wood furniture, it is used in various areas from the beginning of construction to the end of the building. In this study, sawdust, which is the waste of a woodworking company, was used. Utilizing the advantages of wood, recyclable and sustainable cement bonded wood composite production practices have been explored. It is aimed to produce nature and environment friendly, ecological and economic and durable composite materials. In this research, it is aimed to determine the optimum ratio by using different ratios of sawdust-cement while keeping the water-cement ratio constant in production. The specimens taken from the production were exposed to high temperature after gaining strength. The strength results, unit weights and ultrasonic pulse velocity results of cement bonded wood composite samples exposed to high temperature were examined. Although cement bonded wood composites are exposed to high temperatures such as 400°C, it has been observed that strength is achieved. With this study, an alternative area was proposed for the evaluation of these wastes.

Ultrasonic Pulse Method - Influence of Internal Compressive Stress on Results of Testing Calcium Silicate Bricks

2016 ◽  
Vol 722 ◽  
pp. 260-266
Author(s):  
Jiří Brožovský
Keyword(s):  
Compressive Strength ◽  
Calcium Silicate ◽  
Pulse Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Ultimate Compressive Strength ◽  
Technical Literature ◽  
Theoretical Assumptions ◽  
Inner Tension

Measuring with ultrasonic pulse method is influenced by various factors, like loading in particular inner tension when material built in a construction is tested. The paper researches influence of inner tension (load) on testing of calcium silicate bricks with ultrasonic pulse method. Calcium silicate bricks were loaded with force corresponding to 0 % (unloaded test specimens), 10 %, 20 %, 50 %, 60 % of ultimate compressive strength with various content of humidity (dried samples, w=2 %, w=8 % and samples saturated with water). It was found that ultrasonic pulse velocity is not considerably influenced at load of 10% and 20% of ultimate strength of bricks. However, ultrasonic pulse velocity considerably decreases after loading at 50% and 60% of ultimate compressive strength. Most of theoretical assumptions concerning mentioned concrete stated in technical literature were confirmed, however, particular values were different because of differences between concrete and calcium silicate bricks.

scholarly journals Effect of Improper Curing on the Properties of Normal Strength Concrete

2018 ◽  
Vol 8 (6) ◽  
pp. 3536-3540
Author(s):  
R. P. Memon ◽  
A. R. M. Sam ◽  
A. Z. Awang ◽  
U. I. Memon
Keyword(s):  
Cement Content ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Controlled Environment ◽  
Normal Strength Concrete ◽  
Normal Concrete ◽  
Normal Strength

In real applications, 28 days are regarded as proper curing time for concrete. There is a self-evident need to minimize the duration of curing days. For this purpose, this research investigates 1 to 7 days of curing and compares it with concrete cured for 28 days. Three grades of normal concrete strength grade 30, grade 35 and grade 40 were made. After curing, two exposure conditions were applied to the concrete, inside laboratory-controlled environment and outside environment. Results indicate that slump increases with cement content in DOE method at constant water content. The concrete density in all grades reduces when the concrete is subject to inside exposure in comparison with outside exposure. Water loss from concrete reduces with increase in curing days in all concrete grades. Compression strength of all concrete grades increases with increase in curing days. For the uniformity of concrete, ultrasonic pulse velocity indicated that with an increase in curing days, concrete becomes denser and a bit void. Results showed that an increase in curing days also improves the surface quality of concrete. The significance point noticed is that there was not much difference in the concrete properties between 7 days of curing and 28 days of curing in all grades.

scholarly journals Effect of Peat on Physicomechanical Properties of Cemented Brick

2014 ◽  
Vol 2014 ◽  
pp. 1-8 ◽  
Author(s):  
Syed Mofachirul Islam ◽  
Roslan Hashim ◽  
A. B. M. Saiful Islam ◽  
Ryan Kurnia
Keyword(s):  
Building Materials ◽  
Low Cost ◽  
Experimental Studies ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Physicomechanical Properties ◽  
International Standards ◽  
Unit Weight ◽  
Materials Used

The popularity of low cost, lightweight, and environmentally affable masonry unit in building industry carries the need to investigate more flexible and adaptable brick component as well as to retain the requirements confirmed in building standards. In this study, potential use of local materials used as lightweight building materials in solving the economic problems of housing has been investigated. Experimental studies on peat added bricks have been carried out. It demonstrates the physicomechanical properties of bricks and investigates the influence of peat, sand, and cement solid bricks to the role of various types of constructional applications. The achieved compressive strength, spitting strength, flexural strength, unit weight, and ultrasonic pulse velocity are significantly reduced and the water absorption is increased with percentage wise replacement of peat as aggregate in the samples. The maximum 20% of (% mass) peat content meets the requirements of relevant well-known international standards. The experimental values illustrate that, the 44% volumetric replacement with peat did not exhibit any sudden brittle fracture even beyond the ultimate loads and a comparatively smooth surface is found. The application of peat as efficient brick substance shows a potential to be used for wall and a viable solution in the economic buildings design.

Analysis of Relations for Determination of Parameters of Various Types of Concrete Based on Ultrasonic Pulse Method Measurement

2014 ◽  
Vol 923 ◽  
pp. 99-107
Author(s):  
Jiří Brožovský ◽  
Jiří Bydžovský
Keyword(s):  
High Performance ◽  
Pulse Propagation ◽  
Pulse Method ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Technical Literature ◽  
Determination Of Parameters

It is often necessary to determine strength of concrete (Normal-weight, High-performance and Light-Weight) in the structure. To determine strength, ultrasonic pulse method is used. However, the basic condition of its effective use is existence of relations between velocity of ultrasonic pulse propagation and strength. These relations are elaborated for normal weight concrete in great extent. However, for other types of concrete, relations for determination of strength on the basis of ultrasonic pulse velocity are stated in technical literature and their practical applicability could be questioned. The paper gives analysis of such relations from the point of view of practical applicability for determination of parameters of concrete built in a structure.

scholarly journals MECHANICAL, THERMAL AND DURABLE PERFORMANCE OF WASTES SAWDUST AS COARSE AGGREGATE REPLACEMENT IN CONVENTIONAL CONCRETE

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Gassan Fahim Huseien ◽  
Ruhal Pervez Memon ◽  
Ziyad Kubba ◽  
Abdul Rahaman Mohd Sam ◽  
Mohammad Ali Asaad ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Elevated Temperatures ◽  
Evaluation Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Conventional Concrete ◽  
Long Duration ◽  
Mechanical And Physical Properties

Wood yields a number of by-products and Sawdust is as useful as others. Sawdust is regarded as a waste material and is effectively utilised as sawdust concrete in the construction of buildings. It is capable to be utilised as light-weight concrete and holds the quality of long duration heat transfer. In this study, three different ratios (1:1, 1:2 and 1:3) volume mix proportions of cement to sawdust were adopted to make sawdust concrete. At varied intervals of 7, 28 and 56 days of air curing, thermal and mechanical properties like workability, density, elastic modulus, strength and heat transfer were probed of mentioned sawdust concrete proportions. The resistance to elevated temperatures was also evaluated after 28 days of age; weight loss, residual compressive strength, surface texture and ultrasonic pulse velocity were considered in evaluation process. The findings showed that increase in sawdust volume affected to decrease the workability, strength and elevated temperatures resistance. However, the concrete having higher proportion of sawdust performed competently and well in terms of thermal conductivity. Moreover, a decrease in the heat transfer of sawdust was also observed. Examining the all-embracing mechanical and physical properties, sawdust can be effectively utilised in the construction of buildings.

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