Effect of Mineral Additions and Metal Fibers on the Resistance of Cracking of the Dune Sand Concretes
Résumé
This article presents the results of tests on the behavior to cracking of concrete made with dune sand compositions containing mineral additions namely silica fume, limestone fillers and metal fibers (0%, 1% and 2%) and studies the influence of water/cement ratio (W/C). Research has shown that the age of cracking and the cracking stress of the selected specimens vary with the rate of mineral additions and fiber content. It has been noticed that the mixture with a water ratio = 0.40 shows an age of cracking shorter than the mixture with a higher ratio (W/C = 0.53) and that the age and the constraint of cracking of dune sand concrete vary with the rate of the mineral additions and fiber content. Indeed, the silica fume and the limestone filler significantly increase the age of the concrete cracking. It is found that the addition of metal fibers slightly reduces shrinkage on the other hand there is very little difference between the different dosages in fiber. In the long term, the action of the fibers is clearer because the reinforced fiber matrices are stabilized more quickly than the control matrices without fibers. The outbreak of the restrained shrinkage cracking is delayed and it appears in form of a network of cracks shorter, not very open and therefore less damaging for the new composite.