Adnan A. Basma’s scientific contributions

A simplified model to predict the ultimate drying shrinkage of concrete is introduced. The model is based on the theory of elasticity. Utilizing the mathematical formulation proposed by Almudaiheem, a computer program was written to provide values for the ratio of the shrinkage of concrete to the shrinkage of paste Rcp. A multiple regression analysis on 250 data points of the output produced the preceding model. The results of the regression analysis indicated that Rcp is dependent on the degree of hydration α and the volume ratio of aggregate Va. To portray actual field conditions, the degree of hydration was assumed to vary with temperature and was determined experimentally. Consequently, Rcp was assumed to vary. The variation in Rcp was assessed through a Taylor's series expansion about the mean. Using appropriate probability distribution, values of Rcp corresponding to various reliability levels were thus evaluated. The validity of the proposed model was investigated by considering experimental data available in the literature. The results indicated that the model provides an excellent basis for predicting the ultimate shrinkage of concrete.