Bamboo Scaffolding Research Articles

Production of activated carbon from bamboo scaffolding waste—process design, evaluation and sensitivity analysis

A feasibility study has been carried out on the preliminary process design of the production of activated carbon from the bamboo scaffolding waste based on 30 tonnes of bamboo waste per day throughput. A comparison of the process economics of the stand-alone bamboo carbonization plant with a plant that is integrated into another major processing facility has been studied. The preliminary process design was based on various literature sources and an economic evaluation, in which the total capital investment (TCI), the production cost, the return on investment (ROI), the cash flow and the internal rate of return (IRR) of the stand-alone plant and integrated plant were estimated. The TCI of the stand-alone plant and integrated plant are HK$ 7,430,000 and HK$ 6,430,000, respectively. Net present values of two plants at various discount factors have been determined and the IRR have been estimated as 13.0 and 20.1% for the stand-alone plant and integrated plant, respectively. Sensitivity analysis reveals that the cash flow of the project would be increased or decreased up to 40, 65 and 120% by varying production factors of cost of chemical activation agent, production capacity and selling price of activated carbon, respectively, in the extent of ±25%.

Paper #49 The twist-lock concept of tissue fixation without knots: observations along the Hong Kong skyline

Paper #49 The twist-lock concept of tissue fixation without knots: observations along the Hong Kong skyline

Column buckling of structural bamboo

Bamboo scaffolding is widely used in construction in the South East Asia, in particular, the Southern China and Hong Kong for many decades. However, bamboo scaffolds are generally erected by scaffolding practitioners based on their intuition and experiences without any structural design. In general, column buckling is considered to be one of the critical modes of failure in bamboo scaffolds, often leading to their overall collapse. This paper presents a research and development project for structural bamboo where the column buckling behaviour of two structural bamboo species, namely Bambusa pervariabilis (or Kao Jue) and Phyllostachys pubescens (or Mao Jue) were investigated. A total of 72 column buckling tests with bamboo culms of typical dimensions and properties were executed to study the column buckling behaviour of structural bamboo. Furthermore, a limit state design method against column buckling of structural bamboo based on modified slenderness was established and carefully calibrated against test data. It is shown that for Kao Jue, the average model factors of the proposed design method are 1.63 and 1.86 for natural and wet conditions, respectively. Similarly, the average model factors of the proposed design method for Mao Jue are 1.48 and 1.67 for natural and wet conditions, respectively. Consequently, the proposed design method is shown to be adequate. With the availability of design data on the dimensions and the mechanical properties of structural bamboo together with the proposed column buckling design rule, structural engineers are encouraged to take the advantage offered by bamboo to build light and strong bamboo structures to achieve enhanced economy and buildability.

A comprehensive framework for assessing and selecting appropriate scaffolding based on analytic hierarchy process

Problem: Bamboo scaffolding has been widely used in South China, Hong Kong, and Southeast Asia for many years. Bamboo scaffolding is more economical, but its safety record is relatively poor. Conversely, metal scaffolding is more expensive, but its use in these regions has increased in recent years because it is relatively safe. The assessment and selection of the most appropriate type of scaffolding for a particular construction project is always a concern for project managers. Method: This paper suggests a comprehensive assessment framework that enables project managers to take a number of major quantitative and qualitative factors into consideration when making scaffolding decisions. This framework is based on the Analytic Hierarchy Process methodology and a survey among project managers in Hong Kong. Results: The research reveals that the overall performance of metal scaffolding is believed to be better than bamboo scaffolding. A sensitivity analysis has also been conducted to investigate the impact of various factors on the final decisions. Impact on Industry: The proposed assessment framework can be used as a supporting tool for project managers in the selection of scaffolding for their projects.

Polymicrobial Outbreak of Intermittent Peritoneal Dialysis Peritonitis during External Wall Renovation at a Dialysis Center

To investigate an outbreak of peritonitis in intermittent peritoneal dialysis (IPD) patients. An outbreak investigation was performed to identify the etiology of the polymicrobial outbreak, and a retrospective case-control study was conducted to assess the risk factors for development of peritonitis. Renal dialysis center. Ten episodes of peritonitis occurred in 8 of 61 patients over a 6-month period in which 669 IPD procedures were analyzed. Field visit to renal dialysis center to examine the entire IPD procedure, inspect the hospital environment, and perform air bacterial count. The environmental factors and risk factors contributing to the polymicrobial peritonitis outbreak in IPD patients. The incidence of IPD peritonitis was determined before and after interventions. The causative organisms included Acinetobacter baumanii (6), Stenotrophomonas maltophilia (2), Pseudomonas aeruginosa (1), Candida albicans (1), C. tropicalis (1), Enterococcus (3), and Enterobacteriaceae (2). Four episodes of peritonitis involved infection by more than one organism. Air sampling of the environment detected a median of 110 colony forming units of bacteria per cubic meter of air, 10% of which were found to be Acinetobacter baumanii. The source of this polymicrobial outbreak was attributed to the bamboo scaffolding structure covering the external wall of the hospital during renovation. A retrospective case-control study indicated that the absence of the flush-before-fill step was a risk factor for development of peritonitis. In addition to invasive aspergillosis in transplant or oncology patients, Acinetobacter peritonitis in dialysis patients should be considered another microbial cause of outbreak associated with hospital renovation.

Behaviour-based safety management in Hong Kong's construction industry: the results of a field study

Hong Kong's construction industry has had a poor site safety record for over a decade. Behaviour-based methods of safety management (BSM) have proved successful in other industries and in other countries. Hence, this study aimed to test the effectiveness of BSM by applying goal-setting and feedback interventions to specific areas of safety performance on Hong Kong Housing Authority construction sites. Using a within-group experimental design and with the use of a proportional rating safety measurement instrument, data were collected on the effectiveness of BSM on Hong Kong sites. The data were recognized as time series data; this has been a serious methodological oversight in much previous research. The data were analysed using autoregressive moving averages models, and the results were mixed in that a significant improvement in safety performance occurred in the housekeeping category of intervention but no improvement was observed in the access to heights and bamboo scaffolding categories. Based on these results a goal setting/expectancy theory model of site safety improvement has been synthesized, and the lack of provision of an adequate safety infrastructure has been identified as a serious impediment to improvement.

Behavior-based safety management in Hong Kong's construction industry

A behavior-based approach to industrial safety management has been advocated by many authors and has been found to effectively improve safety performance in different industrial settings and on different continents. This paper reports on the implementation of a behavior-based safety management program in the Hong Kong construction industry. The behavior-based safety management techniques of performance measurement, participative goal setting, and the provision of performance feedback were introduced in a carefully controlled field experiment on seven public housing construction sites in Hong Kong. The paper describes this experiment and explains how the program was implemented. The results of the experiment were mixed. Behavior-based safety techniques were highly effective in bringing about improved performance in site housekeeping, but significant improvements in access to heights were only observed on two of the seven sites, and there was found to be no significant improvement in the use of bamboo scaffolding during the experimental intervention. The paper presents these results and discusses factors that may have contributed to the limited effectiveness of the techniques in the latter two performance categories.

Stability analysis of semirigid steel scaffolding

Skeletal structures with members under high axial loads, defined as brittle structures, are widely used in practice. Structures in this category include space frames, transmission towers, and steel and bamboo scaffolding. The collapse of this type of structure is considerably more frequent than that of the conventional beam-column type of steel building. The structure may fail by a series of members buckling which may be initiated by a single member failure or, by global snap-through instability. In both cases, the connection stiffness plays an important role in affecting the buckling capacity of the structure. The linear analysis of this type of brittle structure is basically not different from the conventional analysis of the beam-column type of structure. However, in nonlinear analysis, their methods of analysis differ since the former requires a careful consideration of the second-order effect due to axial load. This paper details the method specially designed for elastic buckling analysis of scaffolding systems where failure is controlled by instability. Theinfluence of the connection stiffness is included in the analysis by the concept of effective length. The application of the proposed method is demonstrated in a number of worked examples.