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Development of a Simplified Structural Design Procedure for Flexible Pavements in Sudan
Issue:
Volume 1, Issue 1, December 2017
Pages:
1-11
Received:
10 December 2016
Accepted:
23 December 2016
Published:
18 January 2017
DOI:
10.11648/j.ajcbm.20170101.11
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Abstract: The inconsistencies and variations in design of pavements arising from using different methods has become a critical issue in Sudan. This paper is aimed to develop a structural design procedure for flexible pavements in order to simplify the design process by using a software program and provide a uniform structural design result. The literature of the conventional design methods commonly experienced in Sudan was intensively reviewed. In fact, these design methods were not designed to cater for the current needs and conditions of Sudan. Thus, an attempt was made to establish a simplified design procedure to accommodate the ever increasing traffic loads, available pavement materials and significant change in climate conditions in Sudan. Based on previous experiences, a design chart for a particular set of traffic loading and CBR values of subgrade soils and granular materials was developed. A software program using Visual Basic language of the Microsoft was created to facilitate the design process. To verify the validity of the developed design chart, three existing roads in Khartoum were redesigned by the new design chart and compared with their previous designs. The results proved that the new design is more realistic, reliable, and accurate design than the previous design. Therefore, adopting the developed design procedure in Sudan might help in enhancing the performance and sustainability of roads. Finally, recommendations are provided for further improvement in design of pavements in view of future developments.
Abstract: The inconsistencies and variations in design of pavements arising from using different methods has become a critical issue in Sudan. This paper is aimed to develop a structural design procedure for flexible pavements in order to simplify the design process by using a software program and provide a uniform structural design result. The literature of...
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Experimental Study of Steel Slag Used as Aggregate in Asphalt Mixture
Magdi M. E. Zumrawi,
Faiza O. A. Khalill
Issue:
Volume 1, Issue 1, December 2017
Pages:
12-18
Received:
29 September 2016
Accepted:
8 February 2017
Published:
27 February 2017
DOI:
10.11648/j.ajcbm.20170101.12
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Abstract: Steel slag is a by-product of the steel industry and can be used potentially as aggregate in asphalt mixture. This study evaluates the use of Steel Slag Aggregates (SSA) as substitute for natural aggregates in the production of hot mix asphalt (HMA) for road construction. Based on intensive laboratory testing program, the characteristic properties of SSA were assessed to determine its suitability to be used in HMA. Four different percentages (0, 50, 75 and 100%) of SSA were used, and the proposed mix designs for HMA were conducted in accordance with Marshall mix design. The experiments results revealed that the addition of SSA has significant improvement on the properties of HMA. An increase in density and stability and a reduction in flow and air voids values were clearly observed in specimens prepared with 100% SSA. It is concluded that the steel slag can be considered reasonable alternative source of aggregate for concrete asphalt mixture production.
Abstract: Steel slag is a by-product of the steel industry and can be used potentially as aggregate in asphalt mixture. This study evaluates the use of Steel Slag Aggregates (SSA) as substitute for natural aggregates in the production of hot mix asphalt (HMA) for road construction. Based on intensive laboratory testing program, the characteristic properties ...
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Influence of Geometric Parameters of Connections’ Members on Behavior of RC Buildings: A Computational Study
Issue:
Volume 1, Issue 1, December 2017
Pages:
19-25
Received:
2 March 2017
Accepted:
13 March 2017
Published:
7 April 2017
DOI:
10.11648/j.ajcbm.20170101.13
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Abstract: One of the most important structures to resist against lateral loading, are moment frames. It is obvious that the beam-column connections play an important role in frame behavior especially on the lateral displacement of structure. In this study, 3 buildings with 5, 10 and 15 stories respectively was modeled by ETABS software and various dimension was applied on beams and columns of these buildings in order to accurately assess the effect of dimension variation of beam and column in connections. It was revealed that the amount of drift ratio significantly decreased by increasing the ratio of beam height to beam width. Moreover, the enhancement of ratio of column width to column height caused to decrease the drift in connections. The increase of ratio of width of beam to width of column will lead to decrease drift, as well.
Abstract: One of the most important structures to resist against lateral loading, are moment frames. It is obvious that the beam-column connections play an important role in frame behavior especially on the lateral displacement of structure. In this study, 3 buildings with 5, 10 and 15 stories respectively was modeled by ETABS software and various dimension ...
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Common Construction Site Hazards in Nairobi County, Kenya
Kemei Raymond,
James Wambua Kaluli,
Charles Kabubo
Issue:
Volume 1, Issue 1, December 2017
Pages:
26-33
Received:
23 May 2017
Accepted:
31 May 2017
Published:
20 July 2017
DOI:
10.11648/j.ajcbm.20170101.14
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Abstract: This study included collection of field data using questionnaires and analysis of secondary data from Kenya’s Directorate of occupational safety and Health (DOSH) covering the period between 2010 and 2014. Perhaps due to inadequate training in safety and lack of experience, 74% of the workers who were injured or killed when accidents occurred in construction sites were below 40years old. Some 26% of the accidents occurred during the busiest months of the year, June and July, a period which coincides with the closure of financial year. Also, about a third of construction site accidents occur during the busiest hours of the day (10-11 am, and 3-4 pm). Falling from height and being hit by falling objects contributes towards about 64% of all construction site accidents. The majority of construction companies in Nairobi allocate less than 1% of project budget to health and safety. This could be because most companies do not have a clear accident prevention policy. Five administrative factors rated on a scaled of 0-5, were thought to contribute to accidents: (1) reluctance to provide resources for safety (4.10 ± 0.2); (2) lack of staff training (4.07 ± 0.2); (3) safety regulations not enforced (3.98 ± 0.2); (4) workers not safety conscious (3.83 ± 0.2); and (5) top leaders not being safety aware (3.71 ± 0.2). It is recommended that investment in Occupational Health and Safety (OSH) and also in health and safety training should be prioritized in construction industry. DOSH should be empowered to provide customized safety training, workshops and seminars to enable construction workers minimize accident occurrence.
Abstract: This study included collection of field data using questionnaires and analysis of secondary data from Kenya’s Directorate of occupational safety and Health (DOSH) covering the period between 2010 and 2014. Perhaps due to inadequate training in safety and lack of experience, 74% of the workers who were injured or killed when accidents occurred in co...
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