Abdul Karim Mirasa

The effect of calcium hydroxide, alkali dilution and calcium concentration in mitigating the alkali silica reaction using palm oil fuel ash

This study investigated the mechanism of how POFA mitigated the ASR expansion. Two types of POFA; the UPOFA and GPOFA with different fineness were used to replace the cement at 20% and 40% and their effects on the mortar bar expansion, calcium hydroxide, alkali dilution, and calcium concentration were investigated. The results showed that UPOFA has a significant ability to mitigate the ASR, even at a lower level of replacement (20%) compared to GPOFA. The mechanism of UPOFA in mitigating the ASR expansion was through a reduction in the calcium hydroxide content, which produced low calcium concentration within the mortar pore solution. Low pore solution alkalinity signified that UPOFA had good alkali dilution effect. Meanwhile, a higher dosage of GPOFA was required to mitigate the ASR expansion. An increase in the pore solution alkalinity of GPOFA mortar indicated higher penetration of alkalis from the NaOH solution, which reduced the alkali dilution effect. However, this was compensated by the increase in the cement dilution effect at higher GPOFA replacement, which controlled the mortar bar expansion below the ASTM limit.This study investigated the mechanism of how POFA mitigated the ASR expansion. Two types of POFA; the UPOFA and GPOFA with different fineness were used to replace the cement at 20% and 40% and their effects on the mortar bar expansion, calcium hydroxide, alkali dilution, and calcium concentration were investigated. The results showed that UPOFA has a significant ability to mitigate the ASR, even at a lower level of replacement (20%) compared to GPOFA. The mechanism of UPOFA in mitigating the ASR expansion was through a reduction in the calcium hydroxide content, which produced low calcium concentration within the mortar pore solution. Low pore solution alkalinity signified that UPOFA had good alkali dilution effect. Meanwhile, a higher dosage of GPOFA was required to mitigate the ASR expansion. An increase in the pore solution alkalinity of GPOFA mortar indicated higher penetration of alkalis from the NaOH solution, which reduced the alkali dilution effect. However, this was compensated by the increase in...

Cloud Computing Information System Architecture for Precast Supply Chain Management

The precast construction industry is associated with a lot of activities, vast effort, many parties and numerous processes. The parties involved in the precast supply chain including the planning, design, manufacturing, transportation, installation and construction should have efficient communication and access to precise and latest information contributing to the enhanced collaboration, sustainability and improving the integration. The aim of this study is to explore the collaboration tools with proposing the cloud system architecture for the precast supply chain management. The research findings are according to the comprehensive review of the literature on supply chain management, precast construction industry and cloud computing. Findings demonstrates the major problems within the precast supply chain phases comprised of poor planning, ineffective communications among designers and manufacturers, incompetent employees and damage to raw materials, large size and heavy precast components and the poor on-site coordination. These major problems within the precast supply chain phases could contribute to negative consequences on the efficiency, productivity and effectiveness of precast delivery. Therefore, to mitigate and overcome these major problems within the precast construction, the cloud computing implementation as the valuable alternative could be delivered to enhance the efficiencies and effectiveness of the collaboration systems. This research propose and establishes the concepts of valuable collaborative tools, for instance the Cloud Computing Information Systems (CCIS), for assisting the processes, activities, information and networks within the precast supply chain management through increasing the opportunities to attain higher competitive advantages. Initially, it is anticipated that this research will result to the enhanced collaboration in order to deliver more competitive advantages and increase the opportunities for the globalisation of the construction industry. Secondly, it proposes an effective technique to establish innovative visions, enhanced productivity, increased effectiveness, improve integration and sustainability leading to efficient collaboration within the construction industry.