Abstract
Degradation of concrete occurs due to such external effects, as freezing - thaw and carbonation. The degree of damage is, in most cases, evaluated by using a uniaxial compression test, material damage is not directly evaluated. For effective quality evaluation of concrete, it is necessary to evaluate not only the strength but also the degree of damage. Quantitative damage evaluation of concrete is proposed by applying acoustic emission (AE) method and damage mechanics. In the present study, damaged concrete samples are examined, based on fracturing behavior under unaxial compression. AE behavior of the concrete under compression is dependent on the degree of damage, and could be analyzed, applying the rate process analysis. Using Loland's model, a relationship between stress and strain is modeled, and a relation between AE rate and the damage parameter is correlated. By calculating the relative damage from the database based on this relation, damages of concrete due to freezing - thaw and carbonation are successfully evaluated. The procedure is applied to core samples taken from a heavily carbonated concrete structure. Thus, quantitative estimation of damaged concrete is effectively conducted.
