 Fiber-reinforced polymer, FRP, composites have gained increasing recognition and application in the field of civil engineering in recent decades due to their notable mechanical properties and chemical resistance. This paper presents the current state of the art on the key environmental and mechanical conditions affecting the durability and mechanical properties of the main FRP composites used in reinforced concrete, RC, structures. This article was authored by Jesus D. Ortiz, Syed Saman Kedmit Gosar Daladi, Prenet Mullah, and others.