The technical term GRC (glass fiber reinforced concrete) is widely used in the precast industry. This type of concrete, which is obtained by mixing cement, sand, glass fibers and some chemicals, is very durable. Compared to conventional concretes, high compressive, flexural and impact strength is the preferred choice for building facade coatings. In this paper, the usability of sepiolite as a pozzolan in glass fiber reinforced concrete and its effects on mechanical and physical properties were investigated. GRC samples were produced by adding 3% glass fiber by volume to substituted mixtures. Crude and calcined sepiolites were replaced with cement at 5%, 10%, 15% and 20% by weight. Compressive strength, flexural strength, impact strength and abrasion resistance of produced GRC samples were determined. As a result, It was observed that as sepiolite ratio increased, mechanical and physical properties of samples decreased in early and later ages, and crude sepiolite substituted samples had lower mechanical strength than the calcined sepiolite substituted samples.