Cost Effectiveness and SWOT Analysis of Using Conventional or Light-Weight Concrete Materials in Buildings Rested on Weak Soils

The design of reinforced concrete (RC) buildings is always considered a challenge to satisfy all code life-safety requirements, to achieve sustainable performance and to economize the cost using available natural and artificial lightweight material. Using three different types of concrete materials (Normal concrete, Lightweight Scoria concrete, and Lightweight Polystyrene concrete), a 5-stories building, has been designed three times to allow comparing these three different materials. The building is located in the coastal area of Khobar city, Eastern province, Saudi Arabia. The coastal area has mostly reclaimed sites that have layers of backfill with fluctuating salty-ground water tables. The construction sites in this region are generally recognized as weak soil locations with low bearing capacity. Therefore, the aim of the study is to investigate the potential of using lightweight concrete as an effective design option to minimize the bearing loads on the weak soil. The design is carried out using Saudi Building Code. The structure was designed to resist gravitational loads as Khobar city is a low-seismic zone. The impact of using different concrete materials on the required steel reinforcement and the total weight of the building is examined. Finally, cost analysis and SWOT analysis for superstructure and substructure have been performed to estimate the total cost of different types of concrete components of the project. The steel and concrete volume LWC for the multi-story building could be substantially reduced. It is conjectured that the environmentally favorable and economical LWC will encourage the use of scoria, particularly as a viable alternative for superstructure construction.