Norazura Muhamad Bunnori

Quantitative Evaluation of the Relationship between Tensile Crack and Shear Movement in Concrete Beams

This paper investigates the use of acoustic emission (AE) to identify tensile cracks and shear movements in concrete structures. The analysis of AE signals detected during a concrete beam investigation mainly focused on the relationship between signal parameters namely rise time, amplitude, duration and counts. This method allowed crack classification and shear movements to be identified. A laboratory experiment test was completed on a reinforced concrete beam (150 x 250 x 1900 mm). During testing AE data was captured and analysed post-test. Results from the most severely damaged zone, based on visual inspection, was analysed. The results indicated that tensile cracks developed though out the area of analysis, as confirmed by visual observation and relatively little shear movement occurred as would be expected in a reinforced beam.

An investigation on acoustic wave velocity of reinforced concrete beam in-plane source

This paper is presented an investigation on acoustic wave velocity of reinforced concrete beam in-plane source based on AE waveform analysis. Pencil Lead Fracture (PLF) was used to generate sudden release of stress at selected source location. Three threshold levels were considered for determining wave velocity in RC beam. It can be concluded that the wave velocity was dependent to the threshold levels, high threshold level would prolong the TOA of the wave and the velocity would be reduced; which the wave travels in the RC beam at velocities in the range 2410 m/s to 4000 m/s. The wave velocity also decreased as the distance from individual sensor to synchronize sensors increased.

Damage severity evaluation on reinforced concrete beam by means of acoustic emission signal and intensity analysis

Concretes structures have been facing several types of damage mechanisms during their lifetime. The types of common defects in concretes structures are crack formations, corrosion, scalling, and etc. Therefore, an evaluation method such as acoustic emission (AE) is required for assessing the deterioration on concretes structures. This paper provides a brief discussion on the evaluations of the acoustic emission signal strength to the health monitoring of reinforced concrete structures beams. Small scale size beam has been used for this investigation and the AE signal processing is the main principal data in this work for assessing by using the statistical quantitative technique, which is known as intensity analysis (IA).This type of technique is able to quantify and evaluate the damage severity on concretes structures. Eventually, the results presented in this research using AE signal strength are greater parameter in determining the micro and macro cracking and also the damage mechanism level on concretes structures.

An Overview Current Application of Artificial Neural Network in Concrete

This paper presents the overview of aArtificial Neural Network (ANN) in the scope of civil engineering application. ANN is one of the artificial intelligence (AI) applications which are currently one of the effective methods used by engineers and researchers to solve technical problems in many scopes of engineering field. One of the explicit criteria of ANN is the ability of the network to deal with the incomplete data and have the capability of learning from experience. This network is also able to adapt to new and changing situation or environment.

Characteristics of Treated Palm Oil Fuel Ash and its Effects on Properties of High Strength Concrete

Palm oil fuel ash obtained from palm oil mill was treated via screening, grinding and heating to improve its pozzolanic reactivity. The characteristics of the palm oil fuel ash before and after treatment were monitored to assess the changes in the properties of the palm oil fuel ash. The resulting ultrafine palm oil fuel ash was then utilized to produce high strength concrete by replacing the ordinary Portland cement at 0, 20, 40 and 60% on mass-for-mass basis. The results show that the treatment process undertaken reduces the particle size, diminishes the unburned carbon content, while at the same time increases the glassy phases. The utilization of the ultrafine palm oil fuel ash in high strength concrete was observed to improve workability especially at higher ultrafine palm oil fuel ash content. In addition, the long-term compressive strength of the high strength concrete was significantly increased with the ultrafine palm oil fuel ash inclusion. Further, the long-term rapid chloride permeability was significant reduced especially at higher ultrafine palm oil fuel ash content of 60%, which could be translated into superior durability performance.

An observation of noise intervention into acoustic emission signal on concrete structure

This paper is presented the observation of noise intervention into acoustic emission (AE) signal on reinforced concrete beam based on data recorded in the AEWin software at different pre-set thresholds manually. Two kinds of sources were selected; namely in-plane source and out-plane source. The correlation between threshold levels and number of hits has been observed. It can be concluded that for both AE sources in-plane and out of plane at the lower threshold level, huge hits were produced which including unwanted hits as well as noise. At high threshold level only required data / hits were recorded by AE signals, where the data presented owing to sudden release of stress from pencil lead fracture at selected source location. Thus, it produced lower correlation between threshold levels and a total number of hits recorded as the coefficient of determination for both sources is around 0.8 only and the graph produced is not linear.

Relationship between acoustic emission signal strength and damage evaluation of reinforced concrete structure: Case studies

Relationship between acoustic emission (AE) signal strength and damage evaluation has been reviewed. Several case studies have been referred to get information on that relationship. The notion or any opinion relates to the case study also had been discussed. Reviews of AE signal strength relate to damage evaluation of reinforced concrete structure and other materials are significantly useful for newly researchers.

Health Index Evaluation on Acoustic Emission Signal for Concrete Structure by Intensity Analysis Method

Concrete structures have been facing several types of damage mechanisms during their lifetime. Mostly, the types are commonly defects in concretes structures are crack formations. Therefore, evaluation methods such as acoustic emission (AE) are required for assessing the deterioration on concrete structures. This paper gives a brief on the evaluations of the acoustic emission signal strength to the health monitoring of reinforced concrete structure beam. Small scale size beam have been used for this investigation and the AE signal processing are the main principal data in this work for assessing by using the statistical quantitative technique, which is known as intensity analysis (IA).This type of technique is able to quantify and evaluate the damage severity on concrete structures. Eventually, by using the AE signal strength data, the results indicates are greater instruments in determining the damage mechanism level on concretes structure.

Overview of moment tensor analysis of acoustic emission signal in evaluation concrete structure

This paper is present a review on the evaluation of concrete structure damage by utilizing the moment tensor analysis (MTA) of acoustic emission (AE) source technique. In general moment tensor analysis is concerning the quantitative information on kinematics of cracks according to the AE source. This concept of AE analysis has been developed and mostly applied in reinforced concrete structure. Furthermore, the formulation of the evaluation of MTA is divided to a three different parts which are; namely kinematics crack, crack classification and crack volume. All these kinds of formulation have been established and proved by the previous researches. This paper also provides a brief overview of research work and several research papers on these topics were cited. Finally, this paper concluded with a discussion for future research area.

Applications of Acoustic Emission Technique Associated with the Fracture Process Zone in Concrete Beam – A Review

This paper summarized the recent development within the application of acoustic emission technique in the formation of fracture process zone and the AE energy released during the fracture process in concrete beam specimens. AE technique is a non destructive technique which is a useful tool to study the energy released during the different failure mechanisms in different types of materials and fracture process is one of the failure mechanisms in concrete. Most of the researchers were applied three point bending test on plain concrete in order to determine the facture process zone of the concrete and some of them were used numerical modeling to verify their results. The results between AE data and experimental in different parameters such as specimens size and aggregate size are normally compared. As a conclusion, AE technique is a very useful tool to determine the fracture process zone in concrete.