Experimental study of composite beams having a precast geopolymer concrete slab and deconstructable bolted shear connectors. (1st May 2016)

• Record Type: Journal Article
• Authors: Ataei, Abdolreza; Bradford, Mark A.; Liu, Xinpei
• Is Part Of: Engineering structures. Volume 114(2016:May 01)
• Page Start: 1
• Page End: 13
• Publication Date: 2016-05-01
• Subjects: Bolted shear connectors -- Geopolymer concrete slabs -- Deconstructability -- Composite beam -- Sustainability; Structural engineering -- Periodicals; Structural analysis (Engineering) -- Periodicals; Construction, Technique de la -- Périodiques; Génie parasismique -- Périodiques; Pression du vent -- Périodiques; Earthquake engineering; Structural engineering; Wind-pressure; Periodicals; 624.105
• DOI: 10.1016/j.engstruct.2015.10.041
• Languages: English
• ISSNs: 0141-0296

Abstract

Highlights: First ever tests on composite beams with geopolymer concrete slabs are addressed. Precast panels as slabs in composite beams using bolted shear connectors are proposed. Experimental tests are described with detailed results being given. Establishes that the beams may be deconstructed and the components re-used. Precast panels fail by splitting; a different mode to that observed in push-testing. Abstract: Traditional steel–concrete composite beams are known to exhibit excellent structural characteristics, in terms of their stiffness and strength, when compared with bare steel or reinforced concrete beams. However, within current paradigms of lowering carbon emissions and enhancing the possibly of material recycling, such traditional composite beams cannot be deconstructed easily and their elements are not recyclable because they rely on welded headed stud connectors that are encased within cast in situ concrete to achieve the necessary shear connection. This paper presents the detailed results of quasi-static tests conducted on full-scale composite beams as part of a novel deconstructable and sustainable structural system. For this system, precast concrete slabs are attached to a steel beam using tensioned high-strength friction-grip bolts in clearance holes as the elements to provide the shear connection. The precast slabs are made using geopolymer concrete in lieu of concrete made from ordinary Portland cement, whose manufacture is a major contributor to anthropogenic CO2 emissions worldwide, thereby enhancing the low-carbon attributes of the structural system. The test results demonstrate the very significant ductility of the beams, with substantial interface slips being developed and sustained at loads close to the ultimate strength limit state. The tension induced in the bolts provides sufficient frictional resistance between the precast slabs and steel beams to ensure that the composite system has full shear interaction throughout the range of service loading. It is also confirmed that composite beams with bolted shear connectors can be deconstructed easily at the end of their service life, with the slabs, steel beams and bolts being reusable in other structural applications.