The impact of adjusting the fineness modulus of dune sand on the mechanical behavior of ordinary concrete - Case of granular range of 15 mm

The targeted objective of this work is to present an optimal formulation of ordinary concrete (Dmax=15mm) using local materials from an arid region, by correcting the fineness modulus of dune sand to obtain a preferred sand. We conducted a series of tests on more than 270 cubic specimens (15*15*15) cm³. The use of dune sand alone in the composition of concrete can create problems with the continuity of the granular mix due to its granularity, which is poor in grains larger than 2 mm and a fineness modulus lower than 1.80. These characteristics directly influence the behavior of concrete in both fresh and hardened states, which is why we try to correct the fineness of dune sand (0/1.25) mm by incorporating crushed sand (0/5) mm with targeted fineness modules of 2.2, 2.5, and 2.8. We found that the introduction of corrected sand has a positive influence on the consistency of the concrete as well as its compressive strength. The results obtained for the compressive strength of the concrete correspond to sand with a fineness modulus varying between 2.2 and 2.8, which are the best compared to concrete with a 100% dune sand content.