An investigation into the feasibility of hybrid concrete construction in South Africa

[摘要] IntroductionSouth Africa is currently experiencing a significant increase in infrastructure investment.Forecasts by BMI-BRSCU have shown that the building and construction industry is expectedto grow considerably to 2010, before languishing slightly to 2015. This growth will be drivenin particular by investment in non-residential building (41% growth) and construction (73%growth) activities. Even beyond 2015 however, the demand will still be high on theconstruction industry to provide infrastructure for South Africa's growing population.South Africa is also facing a serious shortage of engineers, technicians and other skilledworkers in the construction industry. This places high demands on designers and contractorsto provide services and to realise projects in ever-reducing time periods and at less cost. Theseconditions have made it increasingly difficult to maintain the required quality of constructionin an industry where mistakes can lead to disastrous consequences.Recent advances in structural materials, structural systems and the way in which projects arehandled, now enables a new look at the possibilities of combining pre-fabrication with on sitework. This method, known as Hybrid Concrete Construction (HCC), has the potential torevolutionize the South African construction industry if applied correctly. Local research intothis technique is however required and it is the aim of this thesis to draw attention to thissubject.Key FindingsHybrid Concrete Construction (HCC) can be applied to any structural project, it will howevernot necessarily be successful. A structure needs to be adapted from the very start to suit aparticular construction method. This ensures that all the advantages of the selectedconstruction method may be achieved. Adapting a structure to a different construction methodrequires a mutual understanding and commitment from all project participants, including thearchitect, engineer, contractor and client. HCC also requires a certain degree of repetition in aproject to be financially viable.A theoretical cost exercise was performed where only the material and erection costs wereconsidered. In this exercise, HCC was found to be slightly less expensive than otherconstruction methods for the Office Building of more than 10 storeys. HCC was also found tobe significantly faster than other construction methods for the Office Building of more than 3storeys. The time calculation was however based on the simplified time estimates from onesource.Because of HCC's shorter estimated construction period, the client can expect to earn revenuefrom a much earlier date. This decreases the relative cost of a HCC project. This advantage,however, needs to be quantified for chosen South African projects.On-site safety is still an important issue with HCC projects. Labourers are not accustomed tothis construction method and it may be necessary to alter current skill development programsto include a crane safety course. The training of qualified riggers and crane operators shouldreceive priority if HCC is to develop in South Africa.This preliminary investigation has shown that Hybrid Concrete Construction (HCC) can befeasible for the South African market. Further investigation is however required to determinethe parameters for which HCC would be the preferred construction method.RecommendationsBased on the findings and conclusions of this investigation, the following recommendationsare made.The following actions should be undertaken by individual South African companies:· Develop relationships with external project partners· Train competent riggers and crane operatorsThe South African concrete industry should invest in the following actions:· Invest in mass-producing precast concrete facilities· Develop a central database of South African projects with information on time,costs, project concepts and layouts to be used as a guideline for decision making· Develop local guidelines for the production and application of self compactingconcrete· Compile guidelines for the design and construction of HCC and precast concreteconstruction in South Africa· Develop a local hidden corbel type connection to its full potential

[发布机构] Stellenbosch University