Durability of concrete containing blended cements in harsh marine environments: 18 years exposure study

Abstract

This paper aims to study the long-term durability of reinforced concrete in Persian Gulf region, as one of the most aggressive marine environments. Ten mixtures with Type II, and V cement and Portland Pozzolanic cements including IS(20), IPnp(15) and IPsf(10) with three cover thicknesses (35, 50 and 70 mm) utilized. In the preliminary laboratory stage, the compressive strength and depth of water penetration measured up to 365 days. Then, in the field stage, specimens exposed in atmospheric condition, tidal zone and totally submerged in seawater to evaluate the 18 years-corrosion performances. In tidal zone, Type V mixtures experienced a high degree of corrosion in the field study and IPsf(10) and IPnp(15) exhibited the best performance up to 18 years exposure. Moreover, in this condition, the corrosion potential of Type V concrete with 35 mm cover thickness had increased after 6 years and its reinforcements experienced pitting corrosion. Generally a minimum 50 mm concrete cover thickness might be proposed as a criterion for long-term durability in tidal zone.