scholarly journals Behaviour of Incorporation of Bacteria in Concrete

2021 ◽  
Vol 889 (1) ◽  
pp. 012022
Author(s):  
Aditya Kumar Tiwary
Keyword(s):  
Flexural Strength ◽  
Healing Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Conventional Concrete ◽  
Concrete Crack ◽  
Micro Cracks ◽  
Enterobacter Species ◽  
Compressive Strength Of Concrete

Abstract The life of the healing in concrete is many years old and when the study was done on this, outcomes were coinciding with the auto-genus healing process which was capable to heal the micro cracks inside cementitious based materials and hereafter research led to the study of autonomous healing. In the autonomous healing process, the main aim was to fill the cracks and heal the fracture at the macro level. This was possible with the help of bacteria that were embedded in the cementitious based material with different technologies and methods. In this paper, Enterobacter species and Cohnii bacteria were incorporated into concrete. The behaviour of bacterial concrete was investigated in terms of compressive, tensile, flexural strength and ultrasonic pulse velocity. It observed that the compressive strength of concrete was increased by 11.5%, flexural strength increased by 11.9%, tensile strength increased by 12.8% with the replacement of Cohnii bacteria as compare to conventional concrete. These bacteria have been proved a positive approach to the healing process in cementitious based material. Also, the important criterion has been studied which is essential when dealing with the autonomous healing process. Both the bacteria generate the calcite that helps to fill the concrete crack and voids if water come in to contact.

scholarly journals Implication of Nondestructive Test NDT for Evaluation of Crack Healing in Asphalt Concret

2020 ◽  
Vol 2 (1) ◽  
pp. 1-5
Author(s):  
Saad Issa Sarsam
Keyword(s):  
Asphalt Concrete ◽  
Healing Process ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Load Test ◽  
Loading Frequency ◽  
Crack Healing ◽  
Micro Cracks ◽  
Before And After

Asphalt concrete practices heavy loading and environmental impacts through the service life of the pavement. Micro cracks usually initiate and accumulate to form various types of distresses. However, asphalt concrete has the ability of self-healing under rest period and environment conditioning. Asphalt concrete is a composite material consisting of aggregates, bitumen, and air voids. Its mechanical behavior is complex due to its dependency of temperature, loading frequency, and strain level. In this investigation, asphalt concrete specimens of wearing course have been prepared in the laboratory and subjected to repeated indirect tensile stresses to initiate the micro-cracks. The test was stopped after 1200 load repetitions, and the specimens were stored in an oven at 60°C for 120 minutes to allow the crack healing process by external heating to start. Specimens were returned to the testing chamber and were subjected to another round of load repetitions. Specimens were tested before and after load repetitions and crack healing with the aid of ultrasonic pulse velocity traversing the specimen using pundit instrument. The healing indicator was the change in pulse velocity before and after the repeated load test and before and after healing process. It was concluded that the velocity decreases as the loading cycles proceeds indicating the start of damage, while the ultrasonic pulse velocity increases after the micro-crack healing process.

scholarly journals Using Support Vector Machine to Improve Ultrasonic Pulse Velocity Test for Concrete

2018 ◽  
Vol 207 ◽  
pp. 01001
Author(s):  
Tu Quynh Loan Ngo ◽  
Yu-Ren Wang
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Support Vector ◽  
Non Destructive Testing ◽  
Testing Methods ◽  
Destructive Testing ◽  
Compressive Strength Of Concrete ◽  
Non Destructive

In the construction industry, to evaluate the compressive strength of concrete, destructive and non-destructive testing methods are used. Non-destructive testing methods are preferable due to the fact that those methods do not destroy concrete samples. However, they usually give larger percentage of error than using destructive tests. Among the non-destructive testing methods, the ultrasonic pulse velocity test is the popular one because it is economic and very simple in operation. Using the ultrasonic pulse velocity test gives 20% MAPE more than using destructive tests. This paper aims to improve the ultrasonic pulse velocity test results in estimating the compressive strength of concrete using the help of artificial intelligent. To establish a better prediction model for the ultrasonic pulse velocity test, data collected from 312 cylinder of concrete samples are used to develop and validate the model. The research results provide valuable information when using the ultrasonic pulse velocity tests to the inputs data in addition with support vector machine by learning algorithms, and the actual compressive strengths are set as the target output data to train the model. The results show that both MAPEs for the linear and nonlinear regression models are 11.17% and 17.66% respectively. The MAPE for the support vector machine models is 11.02%. These research results can provide valuable information when using the ultrasonic pulse velocity test to estimate the compressive strength of concrete.

Ultrasonic Pulse Velocity for In Situ Measurement of Compressive Strength of Concrete

2007 ◽  
Vol 18-19 ◽  
pp. 55-61 ◽  
Author(s):  
C.A. Chidolue ◽  
B.A. Chidolue ◽  
S.N. Umenwaliri
Keyword(s):  
Aggregate Size ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Direct Transmission ◽  
Indirect Transmission ◽  
Mix Proportion ◽  
Compressive Strength Of Concrete ◽  
A Site

In this study, pulse velocities calculated from the time taken by pulses emitted by a transducer to traverse a known thickness of the concrete is utilized in building up a correlation between pulse velocity and strength of concrete cubes and between pulse velocity and age of concrete. Three different arrangements of transmitters and receivers were studied to cover the varieties of problems likely to be encountered on a site. These are direct transmission, semi-direct transmission and indirect transmission. For a particular mix proportion and aggregate size a calibration curve was obtained for in-situ testing of concrete. These curves can be used to determine the relative in-situ strength of similar members or structures.

scholarly journals Empirical Investigation on Compressive Strength of Geopolymer and Conventional Concretes by Nondestructive Method

2021 ◽  
Vol 2021 ◽  
pp. 1-10
Author(s):  
B. Ravali ◽  
K. Bala Gopi Krishna ◽  
D. Ravi Kanth ◽  
K. J. Brahma Chari ◽  
S. Venkatesa Prabhu ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Fly Ash ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Nondestructive Method ◽  
Geopolymer Concrete ◽  
River Sand ◽  
Rebound Hammer ◽  
Compressive Strength Of Concrete

Need of construction is increasing due to increase in population growth rate. The geopolymer concrete is eco-friendly than ordinary concrete. Current experimental investigation was conducted on ordinary and geopolymer concrete using nondestructive testing (NDT) tests like ultrasonic pulse velocity (UPV) test and rebound hammer (RH) test. Cube specimens of dimensions 150 mm × 150 mm × 150 mm are used to conduct these tests at 7, 14, and 28 days. Proportions considered for concrete are cement-fly ash-river sand (100-0-100% and 60-40-100%), cement-fly ash-robo sand (100-0-100% and 60-40-100%) whereas geopolymer concrete fly ash-metakaolin is taken in proportions of 100-0%, 60-40%, and 50-50%. Alkaline activators (sodium hydroxide and sodium silicate with molarity 12M) were used in preparing geopolymer concrete. The major objective of the current study is to obtain relation between compressive strength of concrete and UPV values.

scholarly journals The relationship between the compressive strength and ultrasonic pulse velocity concrete with fibers exposed to high temperatures

2018 ◽  
Vol 3 (1) ◽  
pp. 31
Author(s):  
Belaribi Hassiba ◽  
Mellas Mekki ◽  
Rahmani Fraid
Keyword(s):  
Compressive Strength ◽  
Ultrasonic Velocity ◽  
High Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Cement Ratio ◽  
Compressive Strength Of Concrete ◽  
The Relationship ◽  
The Waves

The paper analyses the effects of high temperatures on the concrete residual strength using ultrasonic velocity (UPV). An experimental investigation was conducted to study the relationship between UPV residual data and compressive strength of concrete with different mixture proportions, cubic specimens with water-cement ratio of 0.35. They were heated in an electric furnace at temperatures ranging from 200°C to 600°C. In this experiment a comparison was made between the four groups which include two types of fibers steel 0,19%, 0,25% and 0,5%, polypropylene: 0,05%, 0,11% 0,16 % by volume. Cube specimens were tested in order to determine ultrasonic velocity. The compressive strength was tested too. According to the results, relations were established between ultrasonic velocity in the specimens and the compressive strength at different temperature and the range of the velocity of the waves were also determined for this kind of concrete. Result of the test showed that UPV test can be successfully used in order to verify the consistency of structures damaged by fire.

Effect of Elevated Temperature on the Strength and Ultrasonic Pulse Velocity of Glass Fiber and Nano-Clay Concrete

2010 ◽  
Vol 163-167 ◽  
pp. 1532-1539 ◽  
Author(s):  
Chung Ming Ho ◽  
Wei Tsung Tsai
Keyword(s):  
Compressive Strength ◽  
Glass Fiber ◽  
Residual Strength ◽  
Elevated Temperatures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Nano Clay ◽  
Compressive Strength Of Concrete ◽  
Temperature Exposure

The objectives of this paper are to find the strength and ultrasonic pulse velocity (UPV) of concrete adding admixtures by glass fiber and nano-clay. Residual strength and residual UPV of concrete specimens subjected to elevated temperatures are investigated. Experiment results showed that adding glass fiber and nano-clay would be beneficial for the later-age compressive strength of concrete. Adding nano-clay could considerably increase the flexural and split strength and the toughness of concrete. It is revealed that adding nano-clay could significantly maintain residual compressive and split strength of specimens after high temperature exposure. Regression analysis results revealed that the residual strength and residual UPV of concrete specimens had a high relevance after elevated temperatures exposure.

Estimating Crack Depth of Concrete Structures Using Ultrasonic Pulse Velocity

2012 ◽  
Vol 496 ◽  
pp. 546-549
Author(s):  
Young S. Cho ◽  
Sang Woo Han ◽  
Hyun Suk Jang ◽  
Sang Ki Baek ◽  
Seong Uk Hong
Keyword(s):  
Human Life ◽  
Crack Depth ◽  
Concrete Structures ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Concrete Crack ◽  
Long Time ◽  
Close Range ◽  
Non Destructive

The concrete structures have the quite close linkage on the human life and it is used for a long time. Therefore, the importance for structure safety had been being continuously increased. The general method in order to measure concrete crack is the non destructive inspection. This method is known efficiently when it is difficult to check the crack through the eyes because of not exposed. Hence, the purpose of this study is measuring a crack depth of concrete by using the ultrasonic pulse velocity. And the Pundit that is one among the supersonic equipment was used in order to proceed with this research. In the first place used the existing methods (Tc-To, BS, T, close range bypass wave) in order to estimate crack depth of concrete. And then new method that the BS method and the T method are combined make an attempt to analyze the error.

scholarly journals Empirical Formula for Assessment Concrete Compressive Strength by Using Ultrasonic Pulse Velocity

2018 ◽  
Vol 7 (4.20) ◽  
pp. 113
Author(s):  
Hameed Shakir Al-Aasm
Keyword(s):  
Compressive Strength ◽  
Empirical Formula ◽  
Salt Content ◽  
Ultrasonic Pulse Velocity ◽  
Ultrasonic Pulse ◽  
Pulse Velocity ◽  
Fine Aggregate ◽  
Acceptable Error ◽  
Statistical Program ◽  
Compressive Strength Of Concrete

Statistical practical program was carried out to establish a fairly accurate empirical formula between compressive strength of concrete and ultrasonic pulse velocity. The work has a strong empirical base, but it is firmly governed by theory. In concrete, the compressive strength of concrete is related to the type, proportion and physical properties of aggregate but it is well known to be intensely affected by the properties of the cement paste, which relate, mainly, to the w/c ratio. The other variables such as age and density of concrete, salt content in fine aggregate and curing method have a relatively little effect on compressive strength of concrete. Therefore, the program involves field testing of reinforced concrete members that their w/c ratio and cube uniaxial compressive strength are known. The results were used as input data in statistical program (SPSS) to develop an empirical formula between the compressive strength of concrete and ultrasonic pulse velocity. The proposed formula was confirmed by the results of previous experiments. Although the relationship between the compressive strength of concrete and ultrasonic pulse velocity physically indirect, the statistical program revealed that the pulse velocity test could be used with acceptable error in evaluating the compressive strength of concrete.  

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