Experimental Study for Structural Behaviour of Precast Lightweight Panel (PLP) Under Flexural Load
Precast lightweight concrete slab is first fabricated in workshop or industrial before construction and then transported to site and installed by skilled labour. It can reduce construction time by minimizing user delay and time for cast-in-situ to increase workability and efficiency. is environmental friendly and helps in resource reduction. Although the foamed concrete has low compressive strength compared to normal weight concrete but it has excellent thermal insulation and sound absorption. It is environmental friendly and helps in resource reduction. To determine the material properties of foamed concrete, nine cubes and six cylindrical specimens were fabricated and the results were recorded. In this study, structural behaviour of precast lightweight panel (PLP) with dry density of 1800 kg/m3 was tested under flexural load. The results were recorded and analysed in terms of ultimate load, crack pattern, load-deflection profiles and strain distribution. Linear Voltage Displacement Transducers (LVDT) and strain gauges were used to determine the deflection and strain distribution of PLP. The theoretical and experimental ultimate load of PLP was analysed and recorded to be 70 and 62 kN respectively, having a difference of 12.9%. Based on the results, it can be observed that PLP can resist the adequate loading. Thus, it can be used in precast industry for construction purposes.
Structural performance of FCS wall subjected to axial load
Abstract The primary purpose of this paper is to present the structural behavior of precast foamed concrete sandwich walls (FCS) strengthened with double steel shear connectors (DSC) subjected to axial load. The discussion of results addresses the effect of slenderness ratio (H/t) on the behavior of the walls. It also addresses the significant effects of using double shear connectors on these behaviors compared to single steel shear connector (SSC). The FCS wall was modeled using ABAQUS and validated by the results from experiment and previous research. Parametric finite element study (FEA) was conducted by simulating these walls with various H/t under axial load. The structural behavior recorded from FEA includes its ultimate load, failure mode, load-deflection profiles, strain distribution across the wall’s thickness, and ultimate shear load. It was found that as H/t increased, the ultimate load decreased but the maximum horizontal deflection increased. FCS with H/t ⩽25 failed from crushes and cracks within the top and bottom area while FCS with H/t ⩾25 failed from buckling at its mid-height. It was also noticed that FCS with lower H/t experienced more uniform strain distribution across its thickness. FCS with DSC was able to sustain higher load but it deflected less compared to walls with SSC, caused by higher stiffness due to larger steel areas. It is interesting to find that FCS walls with DSC behaved in a more composite manner and was able to sustain higher ultimate shear force under push of loading test compared to FCS walls with SSC. These findings show that the FCS wall with DSC is suitable to be used as a load-bearing wall.
Mechanics of deformable directed surfaces
Abstract The paper develops a simple, yet complete and consistent non-linear dynamic thermo-elastic shell theory based on the concepts of a two-dimensional directed continuum. The constitutive equations are postulated in a general form. Stress-strain relations are derived using the equation of energy balance and the two entropy production inequalities, which are rewritten in a special form. The linear theory is discussed in detail. The structure of the stress-strain relations is presented in the most general form and then specialized to concrete examples, in particular, to the classical shell theory, using their invariance properties with respective to certain symmetry groups. The elastic moduli are determined by demanding the coincidence of the frequency dispersion surfaces obtained using the two-dimensional theory with the lowest foils of the corresponding surfaces resulting from the three-dimensional theory of elasticity.