摘要:The paper deals with the influence of the composition of cementitious materials on the development of their modulus of elasticity in the early stage of ageing. The primary goal of the paper is to determine the static modulus of elasticity of cement mortars almost from the beginning of their setting. Four cement mortars were produced for the experiment. They differed only in the water/cement ratio and in the amount of plasticizer. All mortars were subjected to continuous measurement of the dynamic modulus of elasticity for 24 hours from the moment of their pouring into the moulds. The measurement involved the ultrasonic pulse velocity method. In addition, the static modulus of elasticity was determined at the mortar age of 24 hours. The results are presented in table and graphical forms.