Modeling of dimensional variations of a dune sand concrete reinforced by addition of steel fibers

Technically, the dune sand concrete (DSC) can replace the traditional concrete in some construction cases. Even economically, this material is also cheaper, since dune sand (with its large availability in the Saharan regions), is used as a single aggregate. In addition, the incorporation of steel fibers into this material can remedy its brittle behaviour and limit the microcracking caused by the high shrinkage that typically characterizes the sand concrete. Moreover, the use of the experimental design approach to model the influence of the fibers content [Vb], the filler content [LF] and the Water/Cement ratio [W/C] on the shrinkage is very attractive.For this, tests of endogenous shrinkage (ES) and the free shrinkage (FS) were carried out on various compositions of dune sand concrete reinforced by steel fibers (FRDSC). The results are then compared with those of the dune sand concrete (DSC) taken as a concrete control. Generally, the addition of steel fibers significantly reduces the shrinkage of the dune sand concrete. At the young age, only small differences were observed when fiber contents passed from a dosage to another; however, at the long term, the fibers effect became more marked. In addition, the use of the experimental design theory was very beneficial for modeling the effect of the studied factors on the studied responses. Although [LF] and [W/C] also significantly influenced the total shrinkage of RFDSCs, [Vb] showed the greatest effect. The recorded optimums in the study field were 0.6, 200 kg/m3 and 1% were for [W/C], [LF] and [Vb] respectively.