Influence of Magnetized Water on Mechanical Properties and Durability of Recycled Aggregate Concrete

The main objective of this study was to investigate the influence of using magnetized water on the mechanical properties and durability behavior in terms of freeze-thaw resistance of recycled aggregate concrete. In addition to the effect of different numbers of water rounds in the magnetic field, other variables including steel fibers, super-plasticizers and silica-fume were considered in the concrete production in order to achieve the ideal possible performance for recycled aggregate concrete made with 100% coarse aggregates replacements. For this purpose, a total of 11 concrete mixes were prepared and tested. At the first step, the effects of the mentioned variables on the basic properties, including workability, water absorption, compressive strength, splitting tensile strength, flexural strength and freeze-thaw durability test were investigated. Additionally, flexural toughness was evaluated in accordance with the post-crack strength (PCS) method and the microstructure of concrete specimens was also observed by using scanning electron microscope (SEM). The results of most experiments indicated that magnetized water, although highly effective on the mechanical properties of concrete, should not be solely utilized as a compensating factor for the defects caused by recycled coarse aggregates. The optimum toughness and durability results regarding the fiber-reinforced concrete mixes produced with recycled coarse aggregates, were related to samples containing silica-fume and 10-rounds magnetized water. Furthermore, the existence of cement replaced by 10% of silica-fume and 10-rounds magnetized water in the concrete mix MW-SF2, increased the durability of the recycled aggregate concrete by an average of approximately 63%.