A Preliminary Study on the Effects of Cracks on Chloride Penetration in Different Concrete

The penetration of chloride ions into concrete is one of the most detrimental processes affecting durability of reinforced concrete (RC) structures. Concurrently, cracks are almost inevitable in RC constructions, providing an easy access to chlorides and therefore an accelerated reinforcement corrosion. In this paper preliminary results are presented, concerning the resistance to chloride penetration of different cracked and uncracked concretes - evaluated in terms of chloride migration coefficient – measured with non-steady state migration test. Sound and cracked prismatic specimens, realized with different cement types and a w/c ratio of 0.45, were tested. A specific cracking procedure was developed to obtain load-induced micro-cracks, characterized by a width ranging between 10 μm and 50 μm. Results showed that in correspondence of the micro-crack, the chloride migration coefficient was subjected to a local increase up to 2.2 times the value measured on sound concrete.