Predicting of the compressive strength of RCA concrete

Abstract

Abstract. The paper presents the results of predicting the strength of 61 concretes made with the use of recycled concrete aggregate (RCA). Five models in the form of first-order polynomials containing two to six variables characterizing the composition of the mixture were formulated for this purpose. Factors for unknowns were selected using linear regression in two variants: with and without additional coefficient. For each model, the average absolute error of the concrete strength estimation was determined. Because of the various consequences of underestimation and overestimation of the results, the analysis of models quality was carried out with the distinction of the two cases. The results indicate that the key to improving the quality of models is to take into account the quality of the aggregate expressed by the ACV parameter. Better match results were also obtained for models with more variables and the additional coefficient.

The influence of RCA addition on selected parameters of concrete

“…Common calculation methods and reinforcement detailing allows to effectively predict the behaviour of the structure in which concrete with RCA was used as good as those where only NA was used. Attempts are also made to estimate certain properties of concrete with the use of RCA using mathematical models based on experimental results [12,13]. The results of the attempts are ambiguous.…”