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Mechanical properties of green concrete with Palm Nut Shell as low cost aggregate

  • Authors: Agbenyeku, Emem-Obong Emmanuel , Okonta, Felix Ndubisi
  • Date: 2014
  • Subjects: Sustainable construction , Prestressed concrete construction , Concrete - Testing , Building materials , Palm Nut Shell
  • Type: Article
  • Identifier: uj:5077 , ISBN 9781614994657 , ISBN 9781614994664 , http://hdl.handle.net/10210/13648
  • Description: The cost saving benefits of aggregate replacement in concrete works are well documented. The utilization of Supplementary Aggregate Materials (SAMs) in concrete engineering without compromising standards in concrete works remain very attractive to both infrastructure developers and design engineers. However, there is continual search for low cost beneficial substitute materials. The mechanical properties of green concrete produced from Palm Nut Shell (PNS) as coarse aggregate was investigated. The abundance of PNS (light weight waste product of palm oil production) in West Africa created the impetus for the study. Series of laboratory tests such as; Slump, Compaction factor, Density, Schmidt hammer and Compressive strength tests were conducted on specimens of 10, 20, 30, 40 and 50% replacements of dry weight of PNS as coarse aggregate and specimens of natural aggregate as control sample. The specimens were cured at relative humidity (RH) of 95-100% and temperature (T) of 22-25oC in a chamber for periods of 7, 14, 21 and 28 days. The results showed the PNS samples to have relatively medium to high workability ranging from 24-47 mm for slump height and values of 0.85 to 0.90 for compaction factors. A general strength development was observed across the different samples with the PNS sample reaching strength of 48.7 N/mm2 at 28 days curing. The 50% replacement specimens which mobilized UCS of 28.7 N/mm2 met the requirement for lightweight concrete however, 30% is the optimum for a partial aggregate replacement in green concrete as UCS of 39.2 N/mm2 was mobilized in 28 days. Thus PNS is a suitable concrete constituent and can be a major cost reduction factor especially in low cost rural projects with streamlined loading requirements.
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Assessment of construction waste management in the Greater Accra Region construction industry - Ghana

  • Authors: Agbozo, Setsofia Kwadjo
  • Date: 2018
  • Subjects: Construction and demolition debris , Construction industry - Ghana - Management , Construction industry - Waste disposal - Ghana , Sustainable construction
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/284717 , uj:30762
  • Description: Abstract: The construction industry is a key sector in the development and economic growth of Ghana. However, the industry has not escaped the challenges facing other countries worldwide in terms of construction waste management in the industry. This study assesses the factors, effects, and measures of minimising construction waste, the extent of material wastage, and the environmental impact of construction waste in the construction industry of the Greater Accra Region Ghana. The data used in this study were derived from both primary and secondary sources. The secondary data were collected via a detailed review of related literature. The primary data was collected through a questionnaire which was distributed to construction professionals. Out of the 200 questionnaires sent out, 132 were received, representing a 66% response rate. Findings revealed that project complexity, site conflicts among construction parties, challenges with transportation, and adverse weather conditions were the major factors of waste generation. Furthermore, the study also showed that the extension of time, idling resources, disputes, and the resignation of skilled employees are the effects of construction waste. The study also revealed that proper project planning and scheduling, the availability of clear information and communication channels, frequent coordination between the construction team, complete and proper design at the right time, and frequent progress meetings were the major ways of minimising construction waste. It was also revealed that water pollution, high energy consumed during extraction, and land consumption were the environmental impacts of construction waste. Finally the findings revealed that paints, plywood, roofing tiles, electrical wires, roofing sheets, and conduit pipes (electrical) were the materials that are observed as being the highest wastage materials in the construction industry. , M.Tech. (Construction Management)
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Practitioners perspective for the implementation of sustainable construction in the Ghananian construction industry

Sustainable construction practices challenges - a stakeholders perspective

Sustainable and ecological designs of the built environment

  • Authors: Mbohwa, Charles , Mudiwakure, Alexander
  • Date: 2013
  • Subjects: Sustainable architecture , Sustainable buildings , Sustainable construction , Ecologically sustainable buildings
  • Type: Article
  • Identifier: uj:6176 , http://hdl.handle.net/10210/13783
  • Description: This paper reviews designs of the built environment from a sustainability perspective, emphasizing their importance in achieving ecological and sustainable economic objectives. The built environment has traditionally resulted in loss of biodiversity, extinction of some species, climate change, excessive water use, land degradation, space depletion, waste accumulation, energy consumption and environmental pollution. Materials used like plastics, metals, bricks, concrete, cement, natural aggregates, glass and plaster have wreaked havoc on the earth´s resources, since they have high levels of embodied energy hence not sustainable. Additional resources are consumed during use and disposal phases. Proposed designs for sustainability solutions include: ecological sanitation and eco-efficiency systems that ensure social, economic, environmental and technical sustainability. Renewable materials and energy systems, passive cooling and heating systems and material and energy reduction, reuse and recycling can improve the sector. These ideas are intended to inform the field of ecological design of the built environment.
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Enabling condition-based maintenance in precious metals processing

  • Authors: Ngoma, W. J.
  • Date: 2019
  • Subjects: Ion pumps - Maintenance and repair , Pumping machinery - Maintenance and repair , Ventilation - Equipment and supplies , Sustainable construction
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/417785 , uj:35396
  • Description: Abstract: This dissertation focussed on improving maintenance practice for vacuum pump and ventilation fan systems. The availability and safe operation of assets and plant is a vital consideration in refineries. The optimisation of maintenance is required to improve the plant availability and performance and to reduce operating costs. This dissertation was inspired by the maintenance challenges facing a company that is involved in the refining of special metals. For such a precious metal refinery plant, fume extraction and filtration systems are important to personal safety and processing. Chemicals used in the plants are toxic and hence it is essential that the engineering systems such as extraction fans are always in good condition. Vacuums systems are used as filtration process to separate solids from waste. Product extraction requires precision systems. Proper and suitable maintenance should be deployed on these critical systems, to avoid plant delays and to provide the necessary plant operating environment. Running equipment/systems to failure affects plant performances. A key focus for the company has been installing early detection sensors to monitor and predict abnormal equipment behaviours. The aim of this dissertation was to build on from such investments and examine how maintenance could be improved and better informed by the condition monitoring systems. The research examined existing literature on condition-based maintenance, maintenance and practice at the company under study. Pareto analysis was used to define the critical assets and problems that dominated the escalating maintenance costs. This allowed focus on the big hit strategies (big gains). The research was conducted in three sections around the entire plant at Precious refinery plant, these sections are as follows, Main extraction fan system, Material handling extraction fan system and Other precious vacuum system. Process data was collected on existing sensors, analysed and used to infer condition of critical assets. New statistical tools such as process capability index were introduced to enable tracking the condition of the equipment. Process capability index values for processes in control and out of control were defined and these can be used for tracking system deterioration and enabling predictive maintenance. The focus was on investigation of failures on vacuum pumps and ventilation fans. The research demonstrated the potential for existing sensors and data to be used in predictive maintenance to alert maintenance teams to attend to vacuum pumps and fans pre-failure and hence improve plant availability, operations and reduce cost. , M.Ing. (Engineering Management)
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Review of the application of nanotechnology for sustainable construction materials

A conceptual systems framework for the built environment

  • Authors: Prazeres, Gabriel Luis Alcantara
  • Date: 2012-02-06
  • Subjects: Architecture , Sustainable architecture , Sustainable engineering , Sustainable design , Sustainable construction
  • Type: Mini-Dissertation
  • Identifier: uj:2001 , http://hdl.handle.net/10210/4355
  • Description: M.Phil. , The building/construction industry is undeniably one of the largest; it however is also one of the most inefficient. These inefficiencies span design, construction and the operational phases. The depletion of natural resources and the need for sustainability has however created an urgent need for Architecture, Engineering and Construction (AEC) consultants to address these issues and develop life-cycle integration systems capable of eliminating or substantially reducing waste and efficiently managing the complex process of building design, construction and building operations management. Such systems may be based on advanced production techniques developed in the aerospace industries for the US military and subsequently adapted for use in the industrial manufacturing industry. This dissertation will attempt to explore the following: 1. Identification of current trends in the AEC industry including global warming and sustainable development, to determine the impact on the Building Industry. 2. The relevance of life-cycle engineering and Lean Production philosophy for the AEC industry. Of particular interest is how System life-cycle engineering will benefit the trend towards 'green' environmentally sustainable buildings. 3. Analysis of the AEC Design/Construction/Operation process (Project life-cycle), with the intention of identifying major weaknesses and strengths. 4. Information systems (current and future) and how these are driving change in the industry. Information systems as a backbone for the implementation of a proposed systems framework. The possible implications of life-cycle systems implementation for the architectural profession and other AEC professions will result in new proposed structures, obstacles and opportunities.
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An assessment of the causes and effects of materials wastage on construction projects : a case study of Gauteng Province

  • Authors: Shai, Thapelo Godfrey
  • Date: 2017
  • Subjects: Construction industry - Waste disposal , Construction industry - Waste minimization , Construction projects , Sustainable construction
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/284118 , uj:30675
  • Description: M.Tech. (Construction Management) , Abstract: Wastage on construction sites poses a big problem to the South African construction industry as more and more wastage generated is not properly disposed. This is so because with the chase by the South African government to go low carbon wastage has become problematic for the South African construction industry. This study seeks to determine the the causes of material wastage on Gauteng Province construction sites, the effects of material wastage on the contractors, the impacts of wastage on construction projects, how can wastage be reduced and better managed on a construction site and the benefits of minimised wastage on construction sites in the South African construction industry The data used in this research was derived from both primary and secondary sources. The secondary data was collected through a detailed review of related literature. The primary data was collected through a questionnaire which was distributed to registered and non-registered construction professionals practising in the industry. One hundred and fifty-three questionnaires were received from two hundred sent out, representing a 77 per cent response rate. Findings from the research were analysed using descriptive statistics. Findings from the descriptive analysis revealed that the primary causes of material wastage on the construction site are design and construction errors, design changes and incorrect specification. Wastage in the procurement process is caused by a lack of allocated responsibility for decision-making, incomplete procurement documentation, and poor coordination among parties. Furthermore, material wastage in material handling is due to shipping and suppliers’ errors, inappropriate handling, and inappropriate storage. In addition, causes of material wastage in site operation are poor site management and supervision, and a lack of knowledge about construction during design activities. Material storage wastage is caused by materials being stored far from the point of application, and improper storing methods. Furthermore, contractual causes of wastage are..
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Non-conventional building technologies in South Africa : simulation of the long-term structural performance

  • Authors: Tayo, Bruno
  • Date: 2020
  • Subjects: Building materials , Structural dynamics , Structural design , Sustainable construction
  • Language: English
  • Type: Masters (Thesis)
  • Identifier: http://hdl.handle.net/10210/479885 , uj:43423
  • Description: Abstract: The entire world is facing a housing crisis since the collapse of the economic, and affordability of the conventional construction method house is becoming more expensive each day creating a housing backlog. This housing backlog can be resolved using, non-conventional building technologies, which is also called alternative building technologies or innovative building technologies. However, the public are concerned over the use of non-conventional building technologies. The safety and durability of the technology is in doubt, even though houses built with non-conventional technologies are affordable, flexible, and environmentally friendly. The critical issue is that data on the long-term structural performance and assessment of non-conventional building technologies are not available to convince the public to invest in this technology. This research study is to investigate the non-conventional building technologies housing sample built in 2008 at the National Home Builders Registration Council Eric Molobi Centre Soshanguwe. One sample of the buildings was chosen and the long-term structural performance was simulated by using ABAQUS software through Finite Element Analysis (FEA). The outcomes provide more information regarding the durability of the non-conventional building technologies... , M.Ing. (Structural Engineering)
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