Durability of lightweight concretes containing expanded polystyrene

Bar corrosion in Reinforced Concrete (RC) structures is a major cause of degradation leading to deterioration before design life is attained. Due to the presence of degradation, recent codes have adopted the concept of structures’ durability and service life. The consequences of reinforcement corrosion are the reduction of bars cross section, the formation of corrosion products leading to loss of bond and to the cracking of concrete cover and subsequent spalling. These problems require an interdisciplinary approach involving both material science and structural design competencies. Focusing on corrosion control of bars in RC structures, the paper presents main results about investigation on durability of EPS-based lightweight concretes. The aim of this work is to evaluate the EPS (Expanded Poly-Styrene) effects on durability of RC structures in case of rehabilitation. Three different concrete mixture (a normal-weight concrete and two different mixtures of lightweight concretes with different percentages of EPS) have been exposed to 3.5% wt sodium chloride solution and electrical current in order to obtain an accelerated corrosion corresponding to a penetration rate of about 100 μm/year. The behavior in terms of durability of the concrete with EPS additions was evaluated considering time to cracking and the loss of bar cross-section