scholarly journals Proposing a New Method Based on Image Analysis to Estimate the Segregation Index of Lightweight Aggregate Concretes

Materials ◽  
2019 ◽  
Vol 12 (21) ◽  
pp. 3642 ◽  
Author(s):  
Afonso Miguel Solak ◽  
Antonio José Tenza-Abril ◽  
Francisco Baeza-Brotons ◽  
David Benavente
Keyword(s):  
Image Analysis ◽  
Material Characterization ◽  
Positive Impact ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Pulse Velocity ◽  
Test Method ◽  
The Other ◽  
New Method ◽  
Lower Accuracy

This work presents five different methods for quantifying the segregation phenomenon in lightweight aggregate concretes (LWAC). The use of LWACs allows greater design flexibility and substantial cost savings, and has a positive impact on the energy consumption of a building. However, these materials are susceptible to aggregate segregation, which causes an irregular distribution of the lightweight aggregates in the mixture and may affect the concrete properties. To quantify this critical process, a new method based on image analysis is proposed and its results are compared to the well-established methods of density and ultrasonic pulse velocity measurement. The results show that the ultrasonic test method presents a lower accuracy than the other studied methods, although it is a nondestructive test, easy to perform, and does not need material characterization. The new methodology via image analysis has a strong correlation with the other methods, it considers information from the complete section of the samples, and it does not need the horizontal cut of the specimens or material characterization.

scholarly journals Determination of the apparent porosity level of refractory concrete during a sintering process using an ultrasonic pulse velocity technique and image analysis

2010 ◽  
Vol 16 (1) ◽  
pp. 79-87
Author(s):  
Anja Terzic ◽  
Ljubica Pavlovic
Keyword(s):  
Image Analysis ◽  
Thermal Treatment ◽  
Refractory Concrete ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Apparent Porosity ◽  
Test Method ◽  
Sintering Process ◽  
Porosity Level

Concrete which undergoes a thermal treatment before (pre-casted concrete blocks) and during (concrete embedded in-situ) its life-service can be applied in plants operating at high temperature and as thermal insulation. Sintering is a process which occurs within a concrete structure in such conditions. Progression of sintering process can be monitored by the change of the porosity parameters determined with a nondestructive test method - ultrasonic pulse velocity and computer program for image analysis. The experiment has been performed on the samples of corundum and bauxite concrete composites. The apparent porosity of the samples thermally treated at 110, 800, 1000, 1300 and 1500 ?C was primary investigated with a standard laboratory procedure. Sintering parameters were calculated from the creep testing. The loss of strength and material degradation occurred in concrete when it was subjected to the increased temperature and a compressive load. Mechanical properties indicate and monitor changes within microstructure. The level of surface deterioration after the thermal treatment was determined using Image Pro Plus program. Mechanical strength was estimated using ultrasonic pulse velocity testing. Nondestructive ultrasonic measurement was used as a qualitative description of the porosity change in specimens which is the result of the sintering process. The ultrasonic pulse velocity technique and image analysis proved to be reliable methods for monitoring of micro-structural change during the thermal treatment and service life of refractory concrete.

scholarly journals Analisis Hubungan Kecepatan Gelombang Dengan Kuat Tekan Beton Menggunakan Metode UPV

2020 ◽  
Vol 10 (1) ◽  
pp. 11
Author(s):  
Anggia Eta Rizkiasari ◽  
Abdul Rouf
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Method ◽  
Average Error ◽  
Strength Testing ◽  
Building Structures ◽  
Concrete Compressive Strength ◽  
Strength Based

Until now the use of concrete as a building material is still widely used for building structures. It is important to do concrete compressive strength testing as one of the factors to know the quality of a concrete. NDT (Non-Destructive Testing) is a method of solid quality testing without damaging the object. Testing with the NDT method is considered more efficient than the destructive test method. One method for performing NDT testing is by utilizing UPV (Ultrasonic Pulse Velocity).UPV is a method for estimating concrete compressive strength based on the ultrasonic pulse velocity relationship through concrete with the concrete compressive strength itself. UPV testing works by emitting ultrasonic pulses of 40 kHz through concrete to obtain the travel time of the pulse. Then the resulting time will be calculated the value of its speed and then will be converted into concrete compressive strength.Concrete compressive strength measurement system for high-quality concrete using UPV method can be designed by utilizing relation between ultrasonic pulse velocity with concrete compressive strength. Based on the test results, the average error value of concrete compressive strength testing is 3.04% with a maximum error of 6.63%.

Assessment of Compressive Strength for RC Building Using the Non-Destructive Test and the SonReb Method: A Case Study

2021 ◽  
Vol 1021 ◽  
pp. 45-54
Author(s):  
Mohammed Al-Helfi ◽  
Ali Allami
Keyword(s):  
Compressive Strength ◽  
Concrete Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Test Method ◽  
Technical Institute ◽  
Existing Building ◽  
Destructive Test ◽  
Non Destructive

Non-Destructive methods have greater advantage in assessing the homogeneity, compressive strength, corrosion of rebars in concrete etc. of damaged structures. The aim of the present study is to assess the existing building, which is 41 year old, in the Technical Institute of Amara affiliated with the Southern Technical University, Maysan, Iraq. The research focus on the assessment of the concrete strength and the inspection of the damages in the building. Besides the visual inspection, the ultrasonic pulse velocity and schmidt hammer were used as a non-destructive test method for testing of 30 columns and 15 beams for a building consisting of three floors. The concrete compressive strength was estimated by using SonReb method. The equations proposed by Gasparik, 1984, Di Leo & Pascale, 1994, Arioglu et al., 1996, Cristofaro et al. (EXP), 2020 and Cristofaro et al (PW), 2020 were used for assessment the compressive strength of oncrete. The non-destructive test results indicated that the average strength of the structural elements greater than the design compressive strength of the tested elements. Therefore, the building can be considered structurally is safe.

COMPRESSIVE STRENGTH EVALUATION OF LIGHTWEIGHT CONCRETE WITH EXPANDED GLASS AGGREGATE BY ULTRASONIC PULSE VELOCITY METHOD

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Christopher Collins ◽  
Saman Hedjazi
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Lightweight Concrete ◽  
Lightweight Aggregate ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Normal Weight ◽  
Unit Weight ◽  
Normal Weight Concrete

In the present study, a non-destructive testing method was utilized to assess the mechanical properties of lightweight and normal-weight concrete specimens. The experiment program consisted of more than a hundred concrete specimens with the unit weight ranging from around 850 to 2250 kg/m3. Compressive strength tests were performed at the age of seven and twenty eight days. Ultrasonic Pulse Velocity (UPV) was the NDT that was implemented in this study to investigate the significance of the correlation between UPV and compressive strength of lightweight concrete specimens. Water to cement ratio (w/c), mix designs, aggregate volume, and the amount of normal weight coarse and fine aggregates replaced with lightweight aggregate, are the variables in this work. The lightweight aggregate used in this study, Poraver®, is a product of recycled glass materials. Furthermore, the validity of the current prediction methods in the literature was investigated including comparison between this study and an available expression in the literature on similar materials, for calculation of mechanical properties of lightweight concrete based on pulse velocity. It was observed that the recently developed empirical equation would better predict the compressive strength of lightweight concrete specimens in terms of the pulse velocity.

A New Method to Measure the Gross Volume Density of the Asphalt Mixture Specimen - Brush Wax Method

2014 ◽  
Vol 505-506 ◽  
pp. 154-162
Author(s):  
Long Shi Peng ◽  
Min Gong ◽  
Lan Qiao
Keyword(s):  
Quality Control ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Volume Density ◽  
Test Method ◽  
The Other ◽  
New Method ◽  
Practical Significance ◽  
Technical Requirements

The gross volume density of mix asphalt material compacted specimen is a crucial indicator in the design of asphalt mixture and quality control of asphalt pavement, and it directly determines the asphalt aggregate ratio and the degree of compaction. It has a great practical significance to distinguish and choose the test method of gross volume density correctly. The specific aspects of the methods to determine gross volume density have been controversial. A new method named brush wax method is put forward for these issues. The density, priority, VMA and compactness of asphalt mixture were measured by different methods in the tests. By comparison of the new method and the other methods, the main technical indexes of asphalt mixture obtained by the brush wax method are the only one which greatly satisfies the technical requirements.

scholarly journals Performance Degradation and Microscopic Analysis of Lightweight Aggregate Concrete after Exposure to High Temperature

Materials ◽  
2020 ◽  
Vol 13 (7) ◽  
pp. 1566 ◽  
Author(s):  
Weijing Yao ◽  
Jianyong Pang ◽  
Yushan Liu
Keyword(s):  
Compressive Strength ◽  
High Temperature ◽  
Lightweight Aggregate ◽  
Strength Loss ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Lightweight Aggregate Concrete ◽  
Aggregate Concrete ◽  
Damage Degree

This study analyses the deterioration of mechanical properties in lightweight concrete after exposure to room temperature (20 °C) and high temperature, i.e., up to 1000 °C, including changes in visual appearance, loss of mass, and compressive strength. All-lightweight shale ceramsite aggregate concrete (ALWAC) and semi-lightweight shale ceramsite aggregate concrete (SLWAC) are prepared using an absolute volume method to analyse the relationships between relative ultrasonic pulse velocity, loss rate of compressive strength, damage degree, and temperature levels. Our results show that, under high temperature, the lightweight aggregate ceramsite concrete performs better compared to normal concrete. After exposure to 1000 °C, the ALWAC shows a strength loss of no more than 80%, while the normal concrete loses its bearing capacity, with a similar strength loss as the SLWAC. Furthermore, the relative ultrasonic pulse velocity and damage degree are used to evaluate the effects of high temperature on the concretes, including the voids and cracks on the surface and inside of the specimens, which induces the deterioration of mechanical properties and contributes to the thermal decomposition of the cementing system and the loss of cohesion at the aggregate interface. Based on internal structure analyses, the results from this study confirm that the lightweight aggregate concrete shows a high residual compressive strength after exposure to the high temperature.

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