Abstract:In order to study the influence of different layers and environment on the durability of basalt fiber reinforced polymer(BFRP) sheet, tensile tests of two layer, three layer and four layer BFRP sheet under ultraviolet light, fatigue load and their combination were carried out. The influences of different environments and action time on its tensile strength, tensile elastic modulus and tensile failure strain were investigated. The results show that under the action of three different environments, the tensile strength of the three kinds of BFRP sheet gradually decreases and the decline rate tends to be gentle with the increase of the action time. The change trend of tensile failure strain is similar to that of the tensile strength. The tensile elastic modulus changes little, the fluctuation range is not more than 7%, and there is no obvious regularity. Under the effect of ultraviolet light, fatigue load and their combination, the maximum decrease in the tensile strength of the two layer BFRP sheet was 1560%, 1113%, and 1782% respectively;the maximum decrease in the tensile strength of the three layer BFRP sheet was 466%, 640%, and 1169% respectively; the maximum decrease in the tensile strength of the four layer BFRP sheet is 1178%, 1747%, and 1995% respectively. With the increase of the action time, the influence of the combined action is obviously greater than that of the single action; Under the above three environments, there is no proportional relationship between the tensile properties of BFRP sheet and the number of layers. It is necessary to consider the degradation of tensile strength due to environmental effects on the performance of BFRP sheet used for bridge engineering reinforcement.