Browsing by Author "Alashwal, A"

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item: Conference-Full-text
Impact of fly-ash on carbon emissions in different concrete grades
Paino, J; Perera, S; Alashwal, A; Rodrigo, MNN
Concrete is one of the most used construction materials; however, it contributes to about 7% of all carbon emissions. Various supplementary cementitious materials such as flyash have been considered to enhance concrete performance. There is a limitation of studies that address the influence of fly-ash on carbon reduction in different grades of concrete. Hence, the aim of this study is to analyse the impacts of fly-ash in concrete on carbon emissions in construction projects. A comparison between carbon emissions of portland cement concrete projects and fly-ash concrete projects was conducted using data collected from 20 construction projects in New South Wales, Australia. The results showed that higher the grade of concrete used, higher the carbon dioxide emissions, due to the increase of portland cement needed to achieve the higher grades of concrete. Introducing fly-ash to the concrete mix showed a significant reduction in carbon emissions. However, from the financial perspective, it was found that the rate per cubic metre of fly-ash concrete is 2.1% more expensive than standard concrete mixes. Therefore, the idea of adopting fly-ash into the concrete mix may not deliver cost savings as expected. Overall, this study provided clear insight into the effects of concrete usage on the environment and ways to reduce carbon emission.
item: Conference-Full-text
Selection approaches and methods of construction industry consultant: A systematic literature review
(Ceylon Institute of Builders - Sri Lanka, 2022-06-24) Hummadi, MA; Perera, S; Jin, XH; Alashwal, A; Sandanayake, YG; Waidyasekara, KGAS; Gunatilake, S
Selecting the most appropriate construction industry consultant (CIC) is a crucial process if projects are going to be successful. However, poor performance of CICs and failure to meet a client's needs are common, and the CIC selection process has not been adequately analysed in previous research. A systematic literature review of the CIC selection process will help to clarify the different approaches and methods. The study concluded with three common approaches for selecting the appropriate CIC: pricebased selection, qualification-based selection, and qualification-price-based selection. The selection approach is conducted either by using a direct or a comparative method. The direct approach is based on reputation or past experience with the client, while the comparative selection method occurs through an evaluation process and a list of selection factors. There are two processes involved in the comparative selection method: interview-based selection process and Multi Criteria Decision-Making (MCDM)-based selection process. However, while there are different opinions about what is the best way to select a consultant, the authors assert that the ideal process depends mainly on client and project conditions. Future study is recommended on this topic. This study contributes to the literature on the CIC selection and open the door to further studies such as developing a new selection approach or method and studying factors and criteria of CIC selection.