Reinforcement Wastage and Management Scheme on Selected Apartment Building Projects in Addis Ababa
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Date
2020-12
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Addis Ababa University
Abstract
Cutting reinforcement bars from only one length of 12 meter to suit construction project
requirements result in cutting losses. Major waste is encountered in huge projects such as
housing apartments and high rise building projects during cutting of steel from standard lengths.
The actual amount of wastage generated on-site exceeds the initial estimated amount which leads
to the additional project cost. The loss of rebar can be minimized with proper planning and
optimizing the procedure of bar cutting and fixing. To achieve this goal, the accurate and
detailed information of rebar is extracted, followed by both a rapid and efficient bar combination.
Therefore, reducing steel waste (or minimizing cutting losses) has long been the focus of
academic research in one-dimensional stock design and cutting problems.
This thesis determines the amount of rebar wastage generated on-site by classifying potential
sources of wastage and waste minimization practice applied on-site. This will be applied for the
Army foundation apartment (Kality 1 and Kality 2) project with a total of 28 buildings. Methods
used for data collection and analysis are interview, content analysis method, participatory
observation and case study. The optimum cutting pattern was assessed using structural design
and optimization software such as MaxCut and GoNest 1D. Secondary sources of data were
collected from previous studies done on the subject and various works of literature. As the main
source of data, direct site observation, and accurate measurement were done.
The findings of this research illustrate the direct sources of rebar wastage are cutting bar waste,
un-optimized working procedure, rework, design change, and corrosion. Also, indirect sources of
waste are ahead of time material delivery, management waste, and late deliveries. Rebar waste
minimization implemented on-site are design modification, on-time deliveries, reusing cutoffs,
establishing a kaizen team, and return leftover rebar to the client. Challenges in the site to
enforce material management schemes are undefined scope on material waste, lack of
communication between parties involved, lack of details in drawings, and improper storage of
materials.The recommendations given based on the obtained results are proper and detailed planning of
material usage before beginning project work to reduce the amount of wastage. Planning also
should include a map of storage, transportation, and cutting areas within the site. The
construction industry is a fast-growing field therefore professionals involved in the industry must
update themselves to current practices to avoid misusage of materials and reduce waste.
Designers and consultants should develop a design that includes the most optimal dimensions
and supervision is mandatory for waste minimization.
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Keywords
Rebar optimization, Wastage percentage, Rebar waste reduction