Effect of Ultrafine Additives on Mechanical Properties of Concrete

The study is aimed at assessing the mechanical properties of concrete modified with ultrafine powders produced from construction waste by fine grinding. To achieve this goal, concrete samples with different contents of ultrafine powders in the cement matrix were prepared and tested. The mechanical properties of the samples were assessed in terms of compressive strength and modulus of elasticity. The tests were carried out on concrete samples aged for 7, 14, 21 and 28 days, followed by an analysis of the average values of the three measurements for each time point. The results of the study showed that concrete mixtures containing ultrafine powders have improved mechanical properties compared to control samples. The optimal content of ultrafine powders is 20% of the cement weight. The compressive strength of such concrete samples exceeds the reference values by 46% after 28 days of hardening. This indicates the possibility of using ultrafine powders to improve the performance of concrete structures. Experimental studies have shown that the size, concentration, and chemical composition of ultrafine particles significantly affect the mechanical properties of concrete mixtures modified with ultrafine powders of construction waste