THE EFFECT OF SEA SAND DEREDGER ON THE RESISTANCE OF CONCRETE PIECES REINFORCED WITH METAL FIBERS

The unique properties of concrete, especially reinforced concrete, and economic costs make it the most suitable material for most infrastructures of the world. The aggregate is known as cost reduction factor of concrete production which is now a challenging topic for sustainable development. The most urgent issue in this regard is the environmental impacts of aggregate production. Many areas in the world including Persian Gulf are suffering from excessive deterioration and even inaccessibility to appropriate rock and minerals. The unconventional use of aggregate mines in the country and the limited source of these mines and their accessibility cost made us to consider a solution for thisissue concerning the demolition of dredging materials on the coast and the shortage of materials in far distances of south Iran and margins of Persian Gulf. In this paper, itis tried to use metal fibers for reinforcing this concrete with various percentages of 4%- 6% and 8% in addition to using sea dredging sand (prepared from ShahidRajaee Port Complex of Bandar Abbas) as 25% substitute for fine aggregates in concrete. In so far as mostly in making reinforced concrete armatures, fabricis used instead of bar, therefore, the impact of sea sand on metal fibers for reinforcing this type of concrete will be studied in this application.In most parts of the world, there is a legal restriction on utilization of pits and mines. For example, in parts of the southwest of England, the supply of aggregates isvery low, so that in order to meet the demand, it is inevitable to import it from the Midlands, Ireland and Manche Channel. In a study in Spain, three differentconcrete treatments have been used for construction of the pavement and the impact of dredger sand as a sandstone in production of concrete has been analyzed.In Barcelona, another study has been conducted on making a cement mortar from three types of sand. The purpose of this research was to determine the effect ofadding dredge sand on bonding and consistency of concrete and the effect of modified fine grains on compressive strength in the different mixing scenarios ofconcrete. In their study, Chapman et al concluded that the dredged material of the sea could be used in the manufacturing of concrete [1, 2, 3, 4]. using the dredging materials, as a replacement for the whole or a percentage of the aggregates is a perfect solution. Regarding various aspects related to this new source of materials several studies have contributed.Examples of which are being followed as: Limeira et al. (2010); Limeira et al. (2012); Moradi et al. (2018); Etxeberria et al. (2016); Liu et al. (2016) [5, 6, 7].