Composite slabs structures without formwork: effect of the construction method on the study of the service and ultimate limit states

Abstract

Construction requirements have made it possible to build composite slab structures without formwork. When the concrete has hardened these elements together with the concrete and athe reinforcement make up the composite slab structure. The design of these slabs is different from the standards usually used in slab structures with formwork or shored. Code EF-88 and the current Technical Sheets model do not examine the question of slabs without formwork. The article compares the fulfillment of service and ultimate limita states in two construction methods to point out the effect on the type of joist used, the ratios and lengths of reinforcement, deflections, etc. Depending on the depth of the slab, not using formwork can be economical with regard to reinforcement. In slabs with high depths, the types of joists in the stock lengths available on the market may not be strong enough for use without formwork. Serious problems have arisen in sanitary flooring structures, making it necessary to replace them prematurely.