Paper Title
Optimization of Mechanicalproperties of Fair-Faced Concrete: Role of White Portland Cement

Abstract
The application of Fair-Faced Concrete (FFC) receiving more and more attention in the architectural design of modern buildings due to its aesthetic qualities, infinite range of color tones, natural surface texture, lowering cost by avoiding plastering or veneered, and cladding as well as makes structures more sustainable and easier to recycle.Since the demand of this concrete is increasing day by day, hence it is essential to have exhaustive knowledge about the mechanical properties of FFC. To this purpose, an extensive experimental campaign has been conducted to investigate the mechanical properties as well as aesthetic view of FFC and Normal Concrete (NC) made with burnt clay brick and natural stone aggregates. The FFC was made with a combination of White Portland Cement (WPC) and Ordinary Portland Cement (OPC). In order to optimize the mechanical properties of FFC, five different replacement percentage of OPC by WPC (0, 25, 50, 75, and 100% for brick aggregate and 0, 30, 60, 80, and 100% for stone aggregate) have been investigated.Additionally, an unconstrained nonlinear optimization scheme known as Nelder-Mead Simplex Method was employed for modeling stress-strain behavior of FFC and NC. The experimental results have clearly shown that the compressive strength and modulus of elasticity of FFC is higher than NC (0% WPC). It has been found that up to 50% WPC for brick aggregate and 60% WPC for stone aggregate could be suitably used to obtain maximum mechanical properties of FFC. Furthermore, it has been observed that the outer surface of FFC is smoother, good natural texture of the surface,impressive in color, and brighter than NC.Moreover, a quite good agreement between the measured and the predicted stress-strain curves was observed. Index terms - Fair-faced concrete, White Portland cement, Aesthetical look, Compressive strength, Stress-strain relation, Optimization.