Statistical modeling of physical and mechanical responses of roller-compacted sand concrete made with ternary sand using the experimental design method

•The compressive strength, splitting tensile strength, dynamic modulus of elasticity, and water absorption, were tested.•Mixture design methodology was employed for modeling and analyzing the results.•Statistical models predicting RCSC properties were established as a function of DS, AS, and CS.•Ternary contour plots are used to provide flexibility in optimizing different sand blends.•The use of desert sand contributes to the improvement of RCSC compactness. The rapid development of road infrastructure and the lack of gravel resources have pushed practitioners in the field to develop and propose new alternative materials for road construction. As these novel materials are essentially based on sand, an innovative technique, i.e. the roller-compacted sand concrete (RCSC) technique, has lately been developed. The present paper aims primarily to investigate the effects of the physical characteristics and the mineralogical nature of sand on the mechanical and physical behavior of the RCSC. For this purpose, it was deemed appropriate to choose the design-of-experiment (mixture design) modeling with three factors that are represented by three different types of sand, i.e. calcareous sand (CS), alluvial sand (AS), and desert sand (DS). In addition, it was decided to select the compressive and tensile strength, dynamic modulus of elasticity, and water absorption at 28 days, as responses. Next, a microstructural analysis was carried out using the scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques. First, 21 roller-compacted sand-based concrete (RCSC) mixtures were prepared and then tested. The results obtained indicated that these concretes had a compressive strength between 5 and 25 MPa, with a splitting tensile strength ranging from 1.4 to 2.8 MPa, and a water absorption rate extending from 3.4 to 11.0 %. Moreover, the RCSC mixture including DS (45% ± 10%), CS (45% ± 10%) and AS (10% ± 10%) showed high compressive and tensile strengths; these were found respectively equal to 24 MPa and 2.8 MPa. In addition, the scanning electron microscopy (SEM) analysis showed that the incorporation of dune sand (DS) into the roller-compacted sand concrete (RCSC) increases its compactness. The results of this study can significantly help concrete technologists to determine the optimal sand composition (high DS and CS rates) with a very small quantity of AS (≤20%) to obtain environmentally friendly roller-compacted sand concrete with desired properties.