Abstract

In this study, core samples were taken from column or reinforced wall in order to make reinforcement or restoration. The effect of the element height and volume of voids of these samples to the compressive strength were investigated. C25 type ready to use concrete was used and a column without steel was produced. During the production process, 15 cm reference cube samples were taken from the fresh concrete. After 28 days, 8 cores from reference cubes and 128 samples from column were taken and their compressive strengths were determined. As a result, the average compressive strength of the reference core samples was 36.95 Mpa and according to the height compressive strengths of other samples was ranging between 37.3 and 43.0 Mpa. The ratio of the increasing of the compressive strength changes between 0.95 and 16.37% according to the reference sample. Based on the experimental results, fuzzy Logic method was used for modelling of the experimental results. The paper demonstrates that fuzzy logic can be successfully used in modelling the compressive strength of concrete for different height and volume of voids. This model enables us to easily and reliably estimate the compressive strength of concrete.

Key words: Concrete, reinforcement, compressive strength, prediction model, fuzzy logic.