The article presents the results of research that focused on the selected physical properties of concrete modified using mineral powders. The influence of replacing part of the cement on the physical properties of concrete was studied in the article. The concrete mixtures were modified by quartz, quartz-feldspar and basalt powder in amounts of 10, 20 and 30% of the weight of the cement. The results show that using mineral admixture can reduce concrete absorptivity and porosity and make concrete more watertight.