Hydrotechnical concrete structures located in the Baltic sea environment maintenance conditions, causes of the Baltic sea water and freezing and thawing cycles influencing concrete damages were analyzed in dissertation. Experimental research determined mineral additives (blast furance slag, limestone, coal burning fly ashes, silica fume) influence to hydrotechnical concrete properties and changes after affecting with solution of the Baltic sea water chemical composition and freezing and thawing cycles. Environmental conditions of the Baltic sea port water area and their effect on hydrotechnical concrete with different cements, mineral additives and coarse aggregates were researched and evaluated. Hydrotechnical concrete durability testing methodology was created after performed analysis of different factors like sorption and desorption, chloride diffusion, influence of freezing and thawing cycles to concrete of hydrotechnical structures.