Shahiron Shahidan

Properties Of Concrete With Different Percentange Of The Rice Husk Ash (RHA) As Partial Cement Replacement

The use of pozzolanic material from waste product as partial cement replacement in concrete contribute to reduce the environmental, economic problem through their waste and as well enhance the strength and properties of concrete. Rice husk ash (RHA) is one of the industrial waste that suitably used as a cement replacement due to its pozzolanic properties which can enhance the properties of concrete. In this study, the workability, compressive strength and water absorption of the concrete containg RHA is investigating. The chemical content of RHA also investigated by using X-ray Fluorescence Test (XRF). The different RHA percentage of 5%, 15% and 25% were used in this study with burning temperature 650°C. The concrete cube of size 100 mm x 100 mm x 100 mm were prepared and cured for 7, 14 and 28 days. Based on result, it was concluded that the optimum RHA replacement for cement in this report was 5 %, which provided the highest compressive strength at 28 days.

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 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.

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.

Analysis of the AE signals parameter at the critical area on the concrete beam

This paper enquires the utilization of acoustic emission (AE) to identify the nature of damage such as tensile cracks and shear movements at the critical zone within a structure. The AE parameters were involved in this research are Amplitude, Rise Time and Average Frequency. Some experimental works were performed with the scale of the beam (150 × 250 × 1900 mm) and AE data was captured then analyse by post-test analysis. Eventually, the acoustic emission analysis was successfully identifying the cracks movement accordance to the real observation during the loading cycle.

Experimental Study of Slurry Infiltrated Fiber Reinforced Concrete

Slurry Infiltrated Fiber Reinforced Concrete (SIFCON) is a relatively new high performance and advanced material and can be considered as a special type of Steel Fiber Reinforced Concrete (SFRC). The hooked-end shape steel fiber assist in controlling the propagation of cracking in the matrix by improving the overall cracking resistance and by bridging across even smaller cracks. In this paper, the comparison between the steel fiber reinforcement and BRC wire mesh will obtain and also between the different thickness size. The steel fiber will use from different percentage based on volume frictions which are 0.5%, 1% and 2% with aspect ratio 67. The beam is tested for flexural strength. The relationship between loads versus deflection represented graphically. The highest flexural strength obtained in this research is 19.34 MPa with 2% volume friction of steel fiber.

Physical and Chemical Properties of Coal Bottom Ash (CBA) from Tanjung Bin Power Plant

The objective of this study is to determine the physical and chemical characteristics of Coal Bottom Ash (CBA) obtained from Tanjung Bin Power Plant Station and compare them with the characteristics of natural river sand (as a replacement of fine aggregates). Bottom ash is the by-product of coal combustion during the electricity generating process. However, excess bottom ash production due to the high production of electricity in Malaysia has caused several environmental problems. Therefore, several tests have been conducted in order to determine the physical and chemical properties of bottom ash such as specific gravity, density, particle size distribution, Scanning Electron Microscopic (SEM) and X- Ray Fluorescence (XRF) in the attempt to produce sustainable material from waste. The results indicated that the natural fine aggregate and coal bottom ash have very different physical and chemical properties. Bottom ash was classified as Class C ash. The porous structure, angular and rough texture of bottom ash affected its specific gravity and particle density. From the tests, it was found that bottom ash is recommended to be used in concrete as a replacement for fine aggregates.