An investigation into the time and cost factors for a decision between in-situ and hybrid concrete construction

[摘要] ENGLISH ABSTRACT: The construction industry is a competitive market and contractors need to keep up-to-date with newconstruction methods and technologies. Project teams in South Africa are required to make decisionsduring the early stages of construction projects. These decisions often need to be made in a short timeperiod, and include the decision between various construction methods, such as the decision betweenin-situ concrete construction and hybrid concrete construction.Hybrid concrete construction is a combination of pre-fabricated concrete and cast in-situ concrete toobtain the supreme benefits of their different construction qualities. This method of construction isultimately used to achieve faster, and occasionally, more cost effective construction. Hybrid concreteconstruction, today, is a well-known term in the construction industry and is widely used in the UKand other developed countries. However, the use thereof is limited in South Africa, and in-situconcrete construction remains the conventional method of construction. Possible reasons for thelimited use of hybrid concrete construction are investigated in this study. With the intent of improvingthe construction industry of South Africa, guidelines are provided to assist project teams in a decisionbetween in-situ concrete construction and hybrid concrete construction.The decision between construction methods is based on many factors, such as project time, cost,quality, safety, environmental performance, socio-economic aspects (labour) and client satisfaction.Project time and cost are, however, the most important of these factors. It is stated that the structure ofa building represents typically only 10 % of the construction cost, however, the choice of constructionmethod and material can have significant effects on the cost of other elements throughout the life cycleof construction projects. It is therefore important to measure the whole life cycle cost when decidingbetween construction methods, such as in-situ concrete construction and hybrid concrete construction.The aim of this study is to identify and investigate the factors that influence project time and cost,throughout the life cycle of construction projects, and to provide a framework that can assist projectteams in their decision between in-situ concrete construction and hybrid concrete construction inSouth Africa. The decision between these two construction methods is influenced by a vast number ofvariables that may be difficult to quantify. The framework therefore consists of qualitative informationthat can assist project teams in their decision.The framework provided in this study includes the factors that have an influence on the time and costfor a decision between in-situ concrete construction and hybrid concrete construction. These factorsare identified for the three primary phases in the life cycle of construction projects. These phases arethe design phase, the construction phase and the maintenance phase.

[发布机构] Stellenbosch University