Assessment of the reliability of Structural Concretes During Execution Phases

The quality control of concrete is basically an assessment of compressive strength from which also depends the durability of the material. In the case of important constructions, the control of design prescriptions is not always easy. In addition to the uncertainty factors related to the composition of the material, there are also factors relating to the construction phases. These problems are amplified if the production is on site. These reasons can often suggest to perform, destructive and non-destructive test after the completion of the structure, in order to obtain further information about in-place concrete strength. These investigations, if accompanied by appropriate evaluation procedures, allow to determine the degree of concrete compaction, that if unsatisfactory, makes the material more permeable, less durable and less mechanically efficient. This paper collects the numerical elaboration of resistances measured on cubes made during the concrete placing and on cores extracted after the completion of the structure, for the concrete used in the construction of the "Esaro" Dam facilities (Cosenza, Italy). In addition to the statistical treatment of the sample, aimed to assess the analytical congruence with the homogeneous classes provided in the design, the influence of compaction degree on in place strength value was qualitatively evaluate, with the aid of an analytical methodology.