Behaviour of Voided Slab Utilizing Waste Materials

Abstract

Slab is an essential structural member in any building and it also consumes highest amount of concrete. The major problem with concrete construction is that weight of slab increases with increase in length which limits the span. The use of cement results in emission of carbon dioxide gas to environment up to a certain extent. The objective of research is to minimize the possible weight of slab and utilization of waste material to reduce the consumption of cement. In the present investigation, plastic balls and thermocol balls were used as void formers and cement was replaced by industrial waste i.e. ground granulated blast-furnace slag. Five slabs were casted including one solid conventional slab. Two slabs were casted by replacing 25% of weight of cement with ground granulated blast-furnace slag (GGBFS). The main aim was to determine the load deflection and first crack. The results of voided slab with the void formers of both the materials (plastic balls and thermocol balls) were compared with conventional slab. It has been observed that reduction in weight of voided slab with thermocol balls and plastic balls was 11% and 14% respectively as compared to solid slab. The overall flexural performance of voided slab was found to be better than conventional slab.