Since fiber reinforced composites are often used in an aggressive environment (bridge decks, drainage pipes etc.), it is necessary to estimate their durability and ability to maintain superior mechanical properties in such conditions. One of microscale mechanisms that has a dominant influence on achieving desirable mesomechanical behavior, such as multiple cracking, is fiber-matrix interfacial bond. In the present study, the effect of calcium leaching on the bond properties and fiber-matrix interfacial one are experimentally investigated. To this end, a series of tests is performed, in which a single fiber is pulled out from cementitious matrix under displacement control. Both chemical and frictional bonds are calculated from the measured load-displacement curves, and the effect of environmental exposure on these parameters is clarified. In order to gain a deeper insight into the microscale mechanical phenomena associated with calcium leaching, the fiber-matrix interfaces of both control and chemically attacked specimens are examined by nanoindentation and ESEM. These experiments show that leaching severely degrades the stiffness of the farther transitional zone. and Obsahuje seznam literatury