Shear Behaviour of Ligthweight Sandwich Reinforced Concrete Slabs

A new lightweight sandwich reinforced concrete (LSRC) section has been developed using prefabricated autoclaved aerated concrete (AAC) blocks as infill in the section where concrete is considered ineffective under bending. This paper presents an investigation into the strength and behaviour of LSRC slabs subjected to shear. Eight tests were conducted on four slabs, one solid and three different types of LSRC slabs. Based on the test results, all LSRC slabs exhibited similar behaviour to the equivalent solid slab and had varying shear capacities depending on the profile of AAC blocks infill. The obtained shear capacities were compared with the design values based on several major design codes and found to be within the safety predictions of the codes. ANSYS was employed to develop nonlinear finite element models of LSRC slabs. The numerical results agree well with the experimental one

A model to similate the strength and deformation of concrete in compression

A simple model is developed to represent the strength and deformational characteristics of concrete when subjected to a rate of strain or rate of stress or creep or relaxation testing under uniaxial compression

Strength of ligthweight ferrocement in flexure

Lightweight ferrocement has been made by replacing sand in the cement mortar by foamed blast-furnace slag (fbs) from 0 to 100 in steps of 20. Ferrocement specimens of rectangular section, 200 mm wide à 25 mm thick, have been cast using this lightweight mortar and containing symmetrically distributed 2, 4 or 6 layers of 4 à 22 gauge galvanized iron wire-mesh. A total of 54 specimens were tested under four-point loading on an effective span of 900 mm and the modulus of rupture computed at first crack and at ultimate. A 'strength-density parameter' has been introduced to represent the effects of varying strength and density of the lightweight mortar. The influences of replacement of sand by fbs and wire meshes on the modulii have been studied with respect to a 'mesh-mortar parameter'. The results are expected to be useful in the understanding of the flexural behaviour of lightweight ferrocement in flexure and in the flexural design of ferrocement building elements. © 1991

Punching shear strength of flat slab corner column connections .1. Reinforced concrete connections

This paper presents the details of an experimental study on punching shear strength and behaviour of reinforced concrete corner column connections in flat slabs; a quasi-empirical method is proposed for computing the punching shear strength. The method has also been extended for punching shear strength prediction at interior and edge column connections. The test results compare better with the strengths predicted by the proposed method than those by Ingvarson, Zaglool and Pollet available in the literature. Further, the experimental strengths of interior, edge and corner column connections have been compared with the strengths predicted by the proposed method and the two codes of practice, viz. ACI and BS code, to demonstrate the usefulness of the method