Towards a demountable composite slab floor system

Abstract

Composite slab consisting of in-situ casted reinforced concrete on profiled sheeting, which is connected to steel beams by shear connectors, is a common structural flooring system in office buildings and car parks. The headed welded studs are inexpensive and rather easy to use in-situ because they can be welded to the steel beam through the metal sheeting. A permanent link is created between the composite slab and steel beams leading to rather time-consuming and expensive deconstruction process. Various types of bolted shear connections, recently investigated by various researchers in Europe, Australia, USA, provide a demountable alternative for the flooring system. This paper describes the experimental study using a bolted shear connector consisting of an embedded bolt/coupler and external bolt, originally developed for a prefabricated concrete deck. A full-scale composite beam was tested under working loads up to 6.25kN/m 2 in a 4-point bending. In addition to bolted shear connectors a timber joist is embedded in the composite slab over the web of the steel beam. After the first life cycle, the timber joist provides the cut edge of the slab. The experiment is used to model behaviour in the first life cycle. The composite slab was then cut, demounted, re-assembled and tested again in the second life cycle. The load was applied up to 6.25kN/m 2 and finally to the failure. Multiple arrangements of shear connectors were investigated to analyse performance of "a modified composite slab". Experience gained on the experiments of testing the composite beam in the first and the second life cycle is accompanied by FE analysis.

Japanese Efforts to Promote Steel Reuse in Building Construction

“…Item (5) has been identified as the most significant barrier by many studies (Addis 2006;Dunant et al 2017;Tingley et al 2017;Hopkinson et al 2019). Item ( 2) is addressed by research to develop deconstructable and reusable composite slabs (Gritsenko et al 2019;Jakovljević et al 2020), and proposed connections that minimize welds and rely instead on bolts (Hradil et al 2021). Item (3) is discussed extensively by Pongiglione and Calderini (2015).…”

“…(2) Establish connections deigned for disassembly: The member targeted for reuse should be reclaimed by disassembly process that introduces minimal or no damage. The expense of removing the composite slab (Fujita and Iwata 2008;Gritsenko et al 2019) presents a major concern for extracting beams from existing buildings. The adoption of rigid connections at all beam-to-column nodes, achieved by complete-joint-penetration groove welds and occasionally slip-critical bolted joints, poses a unique challenge to Japan.…”

Design for Deconstruction: Futuristic Sustainable Solution for Structural Design

“…Nevertheless, efforts are being made to devise demountable composite system with flexible reuse. For more examples on the wide research interest in the area of demountable composite slab floor systems, recent investigations were performed by Lawan et al [22] also by Gritsenko et al [23], Ataeia et al [24], Patel et al [25]. Table 5.…”

Experimental Study of Novel Demountable Shear Connectors for Steel-concrete Composite Buildings

“…Additional parameters such as preservation, storage, economy, etc. have emerged, and new key members are taking roles in order to coordinate, which is a new challenge for the engineering society [2].…”

“…Demountable structures could be temporary structures or buildings with standardized geometry. An insightful and simple example is the demountable parking house [2] which has standardized dimensions due to vehicles and lanes, has a temporary need due to some event or demand that can be easily demounted in order to build a new place where it is going to serve the new needs. In addition to this, any kind of structure can be dismantled with proper design, for example, the Stadium 974 in Qatar [3].…”