Cost estimation, optimization and competitiveness of different composite floor systems - Part 1: Self-manufacturing cost estimation of composite and steel structures

摘要

This paper presents self-manufacturing cost estimation, cost optimization and competitiveness of different composite floor systems: composite I beams, composite trusses produced from rolled channel sections and composite trusses made from cold formed hollow sections. Part 1 of this two-part series of papers presents the estimation of the self-manufacturing (direct production) costs for composite and steel structures. The self-manufacturing costs are proposed to be defined as the sum of the material, the power consumption and the labour costs. The material costs of the structural steel, concrete, reinforcement, the shear connectors, electrodes, the anti-corrosion, fire protection and top coat painting, the formwork floor-slab panels and gas consumption are presented in detail. The power consumption costs comprise costs of sawing the steel sections, edge grinding, drilling, welding, stud welding and vibrating the concrete. The labour costs (times) presented define the costs of metal cutting, edge grinding, preparation, assembling and tacking, welding, welding of shear connectors, steel surface preparation and protection, drilling, cutting, placing and connecting the reinforcement, concreting, consolidating and curing the concrete. New approximation functions are proposed for the calculation of some manufacturing times and material consumptions. As the discussed costs vary significantly around the world, the proposed cost expressions are given in the open form to be used for cost estimation in different economic conditions. A numerical example of the estimation of the self-manufacturing costs for a composite I beam floor system shows the suitability of the proposed approach.On the basis of the defined self-manufacturing costs, introduced in Part 1, the cost optimization and the competitiveness of different composite floor systems are discussed in Part 2.