Rudy Tawie

Electromechanical impedance method of fiber-reinforced plastic adhesive joints in corrosive environment using a reusable piezoelectric device

Various nondestructive evaluation techniques exist for structural health monitoring of structures such as acoustic emission, ultrasonic impedance, and impact echo testing. However, these techniques often require expensive and sophisticated hardware with expert operators, limiting their applications to a certain aspect. On the other hand, a relatively new technique known as electromechanical impedance–based structural health monitoring has shown promising results as a local nondestructive evaluation method. To date, only a few numbers of studies have been conducted to develop a reusable lead zirconate titanate sensor for the electromechanical impedance method as majority of researchers have focused on damage detection performance. In this study, a reusable method for the electromechanical impedance method was proposed by using a lead zirconate titanate patch to eliminate the trial-and-error approach to minimize the time requirement for the electromechanical impedance method while reducing the cost for multiple measurements. The proposed reusable device was used to evaluate the damage of the adhesive layer between the fiber-reinforced plastic plates subjected to a corrosive solution while investigating the reliability performance of the device.

Initial findings on perspectives of local contractors on waste minimization barriers and incentives on construction sites

The construction industry is generally a high producer of waste. The implementation of waste minimization strategies on construction sites can potentially make a significant contribution to the sustainability of construction industry. However, there are several pitfalls to waste control on construction sites. This study was a preliminary effort to identify relative importance of factors influencing waste minimization barriers and incentives on construction sites in Kuching, Sarawak. Questionnaires were distributed to 50 practitioners who worked for contractors engaged in various types of construction projects in Kuching, Malaysia. The list of contractors was obtained from the CIDB directory. Survey responses were analysed using the Statistical Package for Social Science (SPSS). From this study, useful information concerning barriers to waste minimization and incentives practices from the perspectives of local contractors in Kuching City was obtained. The results obtained also provided some insights for further work.

Towards Implementation of Green Technology in Sabah Construction Industry

The construction industry in Sabah is one of the major roles for development of social, economic infrastructures and buildings in generating wealth to the state besides the tourism sector. The increasing number of construction projects particularly in the rapid developing city of Kota Kinabalu, green technology as a whole is becoming more significant as it helps to develop effective solutions to encounter global environmental issues. The objective of the research is to identify the awareness and implementation of green technology in construction industry in Kota Kinabalu, Sabah. The methodology of the research is through distributing the questionnaire to the contractors, developers, consultants, architects and state government agencies to the area in Kota Kinabalu only. The questionnaires had been analysed to find out the mean value. 100 questionnaires distributed to the respondents but merely 85 questionnaires collected have been analysed. Based on the findings, 83.5% organisations were aware with the concept of green technology in construction project. In terms of the implementation only 64.7% had been implemented in their organizations. More than 50% from the major players such as contractors, consultants, developers, architects and state government agencies were aware based on six green technology concepts in their organizations. As a conclusion, the awareness towards green policy concept in construction industry is very satisfied. Meanwhile, in terms of implementation need to be increased the number of organizations to be involved in green technology in construction industry.

The role of ultrasonic velocity and Schmidt hammer hardness - The simple and economical non-destructive test for the evaluation of mechanical properties of weathered granite

One of the most significant techniques for evaluation of rock strength is by using the simple and economical non-destructive test (NDT). Previous literatures confirm that there were good correlations between NDTs to the strength properties of granite rocks. The present work deals with the use of Ultrasonic Pulse Velocity and Schmidt Hammer Hardness test to predict the mechanical properties of weathered granite. Cylindrical specimens with the length to diameter ratio of two were prepared for this study and were characterized based on different weathering states. Each of the rock specimens was tested under non-destructive test and then followed by uniaxial compression test to assess the mechanical properties. It was found that good correlations established between the NDTs and the uniaxial compressive strength. The correlation between uniaxial compressive strength and rebound hardness number was demonstrated by exponential form; UCS = 6.31e0.057N, while linear correlations was obtained between the uniaxial ...

The acceptance of green technology: A case study in Sabah Development Corridor

Green technology is the development and application of products, equipment and systems used to conserve the environment which minimizes the negative impact from human activities. The technology can be in the form of green buildings or renewable energy such as hydro, solar and biogas. Development in SDC is still at the early stage, hence there is a prospect to plan for proper green concept implementation. With the increasing number of construction projects particularly in the rapid developing city of Kota Kinabalu, green technology as a whole is becoming more significant as it helps to develop effective solutions to encounter global environmental issues. Although there has been lengthy discussion on the green technology, the visibility of the implementation is still yet to be seen widely in Kota Kinabalu. The implementation of green technology in construction will support dynamic growth of economic development activities, while improving the environment. Hence, it is important to develop a strategic plan t...

Monitoring of bone healing by piezoelectric-EMI method

Smart Piezoelectric devices which have excellent piezoelectric properties have been employed for various sensor and actuators applications. The work presented here is an attempt to demonstrate the feasibility of bone healing monitoring by using piezoelectric-electromechanical impedance (EMI) method that have several advantages such as low cost, portable, light weight and simplicity in measurement. A Piezoelectric sensor (PZT) has been widely used in damage detection of various structures including concrete, pipes and bones due to their unique sensing and actuating properties. The EMI technique has emerged as a universal Structural Health Monitoring (SHM) tool suitable for almost all engineering materials and structures. The method used for this proposed study consists of put healing agent in the host structure in particular cracks bone to be monitored by PZT-needle sensor which is embedded to the host structure. The measurements were taken in the frequency range between 0.04 to 100 kHz at 1 kHz interval u...

Bone-crack detection by piezoeletric-electromechanical impedance method

There is a growing interest in the application of smart materials such as piezoelectric in the biomedical field. The work presented in this paper is an attempt to demonstrate the feasibility of bone-crack detection by using piezoelectric-electromechanical impedance (EMI) method, which has the advantages of low cost, portable and simplicity in measurement. A piezoelectric transducer known as PZT (lead zirconate titanate) was used for actuating and sensing simultaneously and as a means of coupling the electrical and mechanical impedance. The basis of this novel method is to monitor variation in the mechanical impedance of a structural element via electrical impedance of a piezoelectric transducer attached to the host structure. In this study, a PZT transducer was used to detect artificially induced cracks in a bone. EMI measurements were carried out using AD5933 evaluation board for frequency range between 0.04 kHz to 100 kHz. The results obtained from the experiment were analyzed by quantifying the damage index using root mean square deviation (RMSD) of the impedance signals before and after cracks were induced in the bone. The results from the study show the feasibility of the piezoelectric-EMI method to effectively detect physical changes in the bone due to the artificially induced cracks.

Plasticity Index of Soft Soil Modified with Fly Ash and Oil Palm Shell Activated Carbon

Soft soil is in the category of problematic soil because it has low bearing capacity, which is not suitable for construction of infrastructures. However, with suitable ground improvement such as soil modification, these grounds can be used as normal. Soil modification commonly uses cement as an additive to improve the characteristics of soft soils. In this study, soil modification with fly ash and oil palm shell activated carbon was proposed to evaluate the plastic characteristics of modified soft soil. These additives could be potential replacement of cement in order to cut down the usage of cement and hence promotes sustainable and green solution. Peat, a type of soft soil collected from Kuching, Malaysia was added with different types of additives in the laboratory. Laboratory tests were carried out to measure plastic characteristics of the modified soil samples. Plasticity of each sample was measured before and after the soil modification. It was observed that plastic characteristics of the modified soil showed improvement compared to the non-plastic peat soil. The test results were discussed with respect to liquid limit and plastic limit of the soil and effect of type of additives used.