Economic prospects of Steel Reinforced Functionally Graded Concrete (SRFGC) beam structures

Abstract

Engineering materials, for instance, ceramics and concrete, are manufactured with uniform properties purposefully. Because the uniformity is a convenient measurement to ensure the safety design calculation of a structure to be built. The non-uniform material property of concrete can be resulted from mixing, placing, consolidation, and curing processes during the manufacturing of structural members. Therefore, using concrete as a material could lead to an uneconomical use of natural resources because of non-uniformity problems that occur in the structural members. Ideally, in the Functionally Graded Concrete (FGC) material, the properties (elasticity, density, rigidity) of concrete material have to be smoothly graded in the projected directions (longitudinally, transversally, diagonally) by following a governing equation. Hence, FGC has significant advantages over the existing concrete materials in the prominence of cement optimization. In recent progress, many researchers have been studied the mechanical behaviors and production methodologies of FGC enthusiastically. In the state-of-the-art of the FGC developments, two objectives need to be achieved: 1. The manufacturing procedure of FGC material, and 2. The method of analysis to design FGC material. In current developments, the technologies for manufacturing FGC material are still not available for the practitioners. The objective of this paper is to present a method of analysis to design a Steel Reinforced Functionally Concrete Graded (SRFGC) beam element based on the SNI (Indonesian National Standard) of Structural Concrete Requirements for Buildings code 2847:2013. The effects of the non-uniformity of concrete strengths are incorporated into the analysis. Because of the crack-opening assumption in the tensile region of the concrete, the neutral axis position is no longer at the mid-height of the beam cross-section. Hence, an iterative technique has to be employed in the design. An iterative technique is necessary because the internal forces of the beam have to be calculated at the cross-section being designed. The application of the method of analysis is highlighted by designing various type of beam cross-sections, which show the economic benefits of SRFGC beam compared to both the normal and high strength concrete’s material.