THE RELATIVE TOTAL SHRINKAGE STRAIN OF EXPANDED CLAY CONCRETE
The article provides a comparative analysis of the existing design models for determining the shrinkage strain of lightweight concrete. The factors for calculation shrinkage strain of lightweight concrete for the presented models are considered. The object of research is expanded clay concrete based on expanded clay gravel. The subject of research is the unrestrained shrinkage strain of expanded clay concrete. The results of experimental studies of the relative strain of the total shrinkage of expanded clay concrete are presented. A comparison of the experimental values of the shrinkage strain of expanded clay concrete with the calculated values obtained according to the considered models proposed by other researchers, and given in national and foreign standards is carried out. In accordance with the obtained results, it was found that the values of shrinkage strain obtained in the calculation according to the considered models significantly exceed the experimental values, especially for the early period of shrinkage (the first 7 days). The use of the presented design models to determine the shrinkage strain of expanded clay concrete does not guarantee that the correct calculated values will be obtained, and it necessitates additional studies to improve the design models.