Manufactured sand (MS) is widely considered as a sustainable alternative of the river sand (RS). One of the concerns regarding the application of MS in concrete is the influence of workability due to its angularity in nature and high stone powder content. In order to achieve similar workability as RS concrete, a rheology-based design method was established to optimize stone powder content for MS with varied gradations. At mortar stage, Anton Parr rheometer was used to determine rheological parameters, i.e., yield stress, plastic viscosity and thixotropy, by Bingham model for both RS and MS mortar with various lithology, fineness moduli, and stone powder content. The curve fitting least square method was then applied to determine the optimal stone powder content of MS mortar to achieve the similar rheological parameters as RS mortar. The workability was then validated using VKelly test in accordance with modified AASHTO TP 129 at the concrete stage. The mechanical properties were also evaluated for both RS and MS concretes. The VKelly index and mechanical property results indicated that the novel rheology-based design method can be used to obtain an optimized stone powder content for MS concrete with various gradations and lithology achieving the similar workability as RS concrete. Therefore, the effectiveness of this design method was demonstrated and validated. Keyword: manufactured sand concrete; rheology-based design method; stone powder content; rheological behavior

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