عنوان مقاله [English]
Nowadays in most parts of the world, the technology for achieving the concrete with a higher durability has been revolutionized. The usage of the Pozzolan and other additives for this end, has become a common thing in the industry for the past few years. First, the Pozzolan being rather fine and second, its reaction to the Calcium Hydroxide existing in the concrete, are the two factors causing the reduction of the porosity of the concrete and its penetrability and also increasing its durability. This study investigates the effects of egg shell powder on the mechanical attributes of the concrete. In addition, the study attempts to find the optimized percent of the powder in order to reach a higher strength as well as experiments including the percentage of water absorption, the specific weight of the concrete, resistance test –indicating corrosion and permeability- and compressive test on the 15cm cube samples. The samples were prepared by 0%, 10 and 20% egg shell as cement replacement and were tested on 3, 7 and 28 days ones. The normal mixes of concrete were used. The result of the test shows that the samples with 10% replacement have a slump loss by 12%, increasing concrete strength by 1%, reducing in water absorption as 21%, increasing 2% in the specific density, and increasing electric resistance of 90% in comparison with control specimens (0%). The findings indicated the suitability of the egg shell as a waste material and as a replacement of cement in terms of quality and environmental pollution.