Numerical modeling and experimental evaluation of shrinkage of concretes incorporating fly ash and silica fume

Shrinkage is generally considered as an important hardened concrete property. During the drying process, free and absorbed water is lost from the concrete. When the drying shrinkage is restrained, cracks can occur, depending on the internal stresses in the concrete. The ingress of deleterious materials through these cracks can cause decrease in the compressive strength and the durability of concrete. In the first stage of the study, prediction models through gene expression programming (GEP) and neural network (NN) were derived. The data set used for training and testing covers the experimental data presented in the literature. In the second stage of the study presented herein, the findings of an experimental study on drying shrinkage behavior of concretes incorporated with silica fume (SF) and fly ash (FA) were reported. Free shrinkage strain measurements as well as corresponding weight loss were measured over 40 days of drying. The obtained experimental results were also used for the validation of the proposed prediction models. The highest amount of mineral admixture resulted in high shrinkage strain development. Moreover, the proposed NN model also accurately predicted the values obtained from experimental study. The errors obtained from GEP model were very high, especially for SF incorporated concrete Keywords: Shrinkage, modeling, Prediction, Experimental validation, Mineral admixtures