Structural Precast Concrete in Melbourne, Australia

Since its early application in tilt-up construction for industrial buildings, precast concrete has evolved to become the dominant form of multi-storey construction in Melbourne. Flat panel loadbearing walling with insitu or precast floors is the preferred construction method for multi-storey residential buildings, and precast skeletal frames with precast flooring is common on multi-storey commercial buildings. This paper will detail and illustrate the concepts that have been adopted and developed in Melbourne to suit the local market. Buildings range from two to several storeys and from a few hundred to tens of thousands of square metres. Many are of mixed construction, incorporating precast with other structural systems. In the Australian market where weather has little impact on construction methods, precast concrete usually needs to rely on factors other than direct cost savings to compete. In this market the following factors need to be considered when establishing design concepts: High on-site labour costs mean the saving in construction time for a precast structure will frequently have a more significant influence on cost than the quantities of materials. The labour content of the manufacturing process can be significant. The structure should be composed of a small number of different types of elements so that variations of basic types can be produced in the same mould. Connections should be simple and quick to construct. Setting up and adjusting the precast elements should require no fixed scaffolding. Application of these concepts has resulted in the evolution of the following types of structural systems: Panellised structural envelope. Structural precast skeletal frame. Hybrid structure Mixed construction. Each of the above structural systems use a range of standardised components.