摘要:The low resistance to harmful acting of water confined in porous, cement-based materials is a negative feature. As the consequence of porous structure these materials have not sufficient resistance as some physical and chemical detrimental factors. The objective of this paper was to evaluate the impact of organosilicon admixture based on silane and siloxane on physical properties of cement mortar. Internal hydrophobization can significantly improve the durability of a cement materials. At this paper the results of mechanical strength, absorbability and capillary water absorption of internally hydrophobized cement mortar are presented. In addition, a contact angle test was used to assess the changes in wetting angle of cement paste.