Study of Linear Deformation Changes in Heavy Concrete Based on Modified Portland Cement

The investigation results revealed how modified standard Portland cement of grade 42,5 (M400) with 10% of the expanding additive changes  the deformation characteristics of heavy concrete. Heavy concrete of class B 22.5 (M300) with a different water-cement ratio (slump 3 cm and 5 cm) was selected as the object of study, from which cubic specimens of side 10 cm were prepared. The impact of modified cement on concrete linear deformations is determined at the ages of 1, 3, and 28 days under normal setting conditions, and changes in the sizes of the same specimens are checked for three months under air-drying conditions. The study confirmed that the most effective impact of modified cement, as in the case of construction mortars, is also observed in 3–7 days  of curing. It was found that the effect of modified cement is increased with the increase in the water-cement ratio, and a relatively low percentage of expansion through the low water-cement ratio is explained by the certain rigidity of the concrete internal structure.