The effect of sea water as mix water and curing medium on mechanical and durability properties of concrete

Concrete is the most widely used building material in the world. Concrete mixture includes binding material, aggregate and water. With the decrease in fresh water resources in the world, research on the use of seawater in concrete has increased in order to reduce the use of fresh water in concrete, the most widely used building material, and to ensure sustainability. The use of seawater in concrete will have an important place in terms of sustainability by reducing the consumption of fresh water resources. In this study, the effect of using seawater as mixing and curing water on concrete was investigated. The samples were prepared with CEM I 42.5 R cement. Control group samples were produced with tap water. The samples prepared with three different seawater concentrations, namely diluted seawater, normal seawater and concentrated seawater, were cured in two different curing environments: tap water and seawater. Cube samples with dimensions of 100x100x100 mm, reinforced and unreinforced beam samples with dimensions of 100x100x500 mm, and reinforced cylinder samples with dimensions of 100x200 mm were produced in the determined mixtures. The samples were tested for compressive strength at 3, 7, 28 and 365 days. 28-day samples were subjected to ultrasonic sound transmission velocity, wide disc abrasion test, flexural strength, acid attack, sulfate attack, high temperature (250 ºC, 500 ºC, 750 ºC) tests. Accelerated corrosion test was performed on cylinder samples prepared with 16 mm diameter reinforcements. In the accelerated corrosion test performed by applying a constant 12 V current for 160 hours, the current passing through the reinforcement was measured at 8 hour intervals. After the accelerated corrosion test, pull-out test was performed on the corroded samples.