The use of fibers in concrete at relatively low volume fraction has been gaining rising popularity among researchers for the recent years due to its availability, ability to enhance overall performance and cost effectiveness. Fibers are mainly classified according to their origin. Numerous researches have been carried out with natural and artificial fibers separately to elucidate its effect on the various parameters of concrete. However, a little finding is available about the comparative study among these three distinct types of fibers affecting concrete properties. In this study coconut coir, nylon thread and low-cost galvanized iron wire have been selected as natural, synthetic and steel fibers respectively. Coconut coir and nylon thread were mixed at three different percentage of 1.5%, 2.5% and 3.5% respectively by weight of cement. Steel fibre contents 1.5%, 2.5% and 3.5% respectively by weight of concrete. The results were obtained through an experimental investigation that shows the influence of natural, synthetic and steel fibers on rheological and mechanical properties of concrete. Optimum fibre content was 2.5% where steel fibre shows a maximum 17% and 30% rise in compressive and flexure strength respectively. On the other hand, fibres play a great role with its combining effect on the post cracking ductility and energy absorption of concrete.
On account of ever increasing complexities and uncertainties, construction project management has become more and more challenging day by day. As a result, continuous project monitoring emerges as a prime concern for the planned activities to be completed on schedule and within budget. Limitations in traditional time and cost monitoring practices result in time and cost overrun which seriously hinder successful completion of a project. The impact of time and cost at various stages of a construction project is a critical factor in the project's successful completion and management. Most of the construction projects in Bangladesh have completed with extra time which leads the demand of additional cost because of poor project monitoring and controlling system. In these consequences, a widely recognized emerging project monitoring technique, Earned Value Management (EVM) can be introduced to conduct project progress, performance and forecasting. EVM measures the actual work completed on a project at any time with respect to the original cost and schedule by integrating project scope, cost and schedule in order to predict cost and completion timeline. In this study, a three-storied residential building project at Khulna, Bangladesh was considered to perform earned value management for tracking whether the project is either delay or not along with either over budget or under budget at any particular day. The construction operations up to the first six months were assessed using an EVM based on a work-breakdown structure (WBS), in which the real activities and costs were compared to the projected program. The progress of the under constructed project considering cost and schedule were also evaluated through analyzing EVM indexes using Microsoft Project Professional 2019 software. Construction performance was assessed respecting cost variance (CV), schedule variance (SV), cost performance index (CPI) and schedule performance index (SPI). CV and CPI are evidently less than 0 and 1, respectively, indicating thatthe project was on the verge of cost overrun; on the other hand, SV and SPI are both less than 0 and 1, indicating that the project was running behind budget after six months. As a result, if this project is pursued at its current pace, it will be finished behind schedule and above budget. It will undoubtedly assist project rescheduling to bring the performance back to harmony.
Purpose This article aims to signify the influences of the COVID-19 outbreak on the construction sector which resulted in project setbacks, labor shortages, work cuts, time and expense overruns, and financial uncertainty that significantly disrupted major infrastructure development programs worldwide. Approach In order to assess the current perception of the construction sector fighting with COVID-19, an online-based semi-structured and self-reported questionnaire survey was conducted from November 23 to November 30, 2020, involving the Project Manager, Managing Director, Project Engineer, Architect/designer, and Site Engineer. Therefore, raw data were documented (edited, sorted, and coded) by using Microsoft Excel 2019 which was later imported to IBM SPSS version 25.0 to analyze frequencies, percentages, means, standard deviations, ANOVA, and chi-square tests. Findings The majority of the respondents claimed that they have experienced financial and mental difficulties in the forms of losing their job, temporary suspension, deduction in salary, no festival bonus, delayed payment, etc. Participants demanded strict monitoring systems, sufficient medical facilities, and exact pandemic mitigation policies in both the workplace and nationwide. Furthermore, it is vital that the policy-makers should review the strategies and make the necessary adjustments to address any potential problems that arise once in a while like COVID-19. Originality This research will contribute to refined personnel management by analyzing the insight impacts of this pandemic prior to precarious shutoff. Policymakers will surely find it helpful enough for reviewing the current and longer-term impacts of this crisis to organize the plans and implementations regarding effective pandemic management.
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