Effect of Nano Clay on the Durability of Reinforced Concrete Beams under Service Loads and Chloride Attack

Abstract

Durability of reinforced concrete (RC) structures has been increased using different additives under corrosive environments in the recent years. In the present study, 0, 0.5, 1 and 1.5 percentage of nano clay particles were substituted as cement. Therefore, 24 RC beams divided in three groups after 28 days of curing. The first group consists of 8 beams which were tested after 28 days of moist curing. The second and the third groups consist of 8 beams in each group, which were tested after 6 months exposure in chloride solution and wetting and drying cycles, where the third group beams were additionally under service loads. Also, compressive strength and water absorption of the mixtures were evaluated at different ages. Results showed that the addition of nano-clay particles considerably reduces the compressive strength of concretes which consequently decreases the flexural capacity of the beams. In addition, nano-clay particles reduce the half-hour water absorption and increase 24-hour water absorption. Also, results showed that the wetting and drying cycles of chloride solution for 6 months reduces the flexural capacity of the beams, but service loads reduces the negative effect of the exposure. Also, the beams containing nano-clay particles showed better performance under chloride attack.

Keywords

• nano-clay
• reinforced concrete beam
• service loads
• chloride ion
• wetting and drying cycle
• corrosion of rebar