Browsing Faculty of Science and Engineering by Subjects
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Improving construction management practice in the Gibraltar construction industryResearch has shown that 57% of activities in a construction project is non-value adding (waste) which contributes to the poor performance of the sector. While other countries of the world such the USA, UK, Brazil, Nigeria and Israel among others are seeking to understand this challenge and deploy innovative ways and modern techniques to improve it, limited studies have explored factors that contribute to non-value adding activities (NVA) in the Gibraltar construction industry. The current study aims to identify the factors that contribute to NVA on construction sites in Gibraltar and to present an outlook on how this could be minimised using Last Planner System(LPS). A combination of quantative and qualitative research approaches were used. Thirtyone questionnaire responses were analysed and seven semi-structured interviews were conducted. The investigation reveals that the development of unrealistic schedules, lack of adequate training, delayed approval process and work interruption due to the community are the key factors that contribute to NVA. The study found that the suggestions offered by construction professional for minimising NVA align with some LPS principles. The study concludes that some of the current practices, could serve as justification for the introduction of LPS in the construction sector of Gibraltar.
Principles for developing an effective framework to control minerals and rocks extraction impacts, mitigate waste and optimise sustainable quarries managementAn investigation into how and why frameworks are developed led to the understanding of the facts that most frameworks or guides are developed for specific reasons. However, this study reveals that for a framework to be ‘effective’, certain factors ought to be ‘integrated’ in order to specifically address the aim and objectives of the particular framework – especially in specific sectors such as the extractive resources sector. A study of fifteen influential frameworks provided insight as to some outstanding factors that must be atleast considered in developing ‘an effective framework’ for a developing resources extraction sector. Although the knowledge of a granite quarry environment in a developing country has been used in expounding the study, the study is also a referral of ongoing research and can be applicable to the development of similar guides. So, because the principles discussed in this study were also applied in the development of this paper, the principles of this guide could also be applied by governing bodies, local governments, researchers and research institutes, non-governmental and private organisations in the extractive industry and beyond, for the development of ‘effective’ guides aimed at impacts control and waste management.
Structural behaviour of reinforced concrete beams containing a novel lightweight aggregateThis paper reports the results of an experimental investigation into the structural behaviour of reinforced concrete beams incorporating a novel EPS-based lightweight aggregate (LWA) called stabilised polystyrene (SPS) aggregate. Four concrete mixtures with water to cement (W/C) ratio of 0.8 were used. The replacement levels of natural aggregate by SPS were 0%, 30%, 60% and 100%. The volume ratio to manufacture SPS aggregate was 8:1:1 (80% waste EPS: 10% cement: 10% clay). A total of 24 beams were cast and tested at 28-day age. Three types of tension reinforcement were used: 2 bars, 3 bars and 2 bars + shear links. There were no compression bars at the top for all beams. Four point-loading flexural tests were conducted up to failure. In general, it can be observed that the structural behaviour of SPS concrete beams is similar to that of other types of lightweight aggregate concretes used around the world.