The effects of environment types and acting time on the elastic modulus and tensile strength of basalt fiber reinforced polymer（BFRP）were analyzed by performing durability experimental tests under the condition of acid solution

freeze-thaw cycles and coupled effects.The test variables include BFRP diameter（6 mm

8 mm

10 mm）

corrosion age（15 d

30 d

45 d）

freeze-thaw cycles（50—300 times）

etc.The results show that under the action of acid solution

freeze-thaw cycles and coupled actions

the tensile strength is decreased by up to 33.9%

10.5%

31.1%

respectively

for BFRP bars with diameter of 6 mm

by up to 29.2%

6.9%

28.6%

respectively

for those with diameter of 8 mm

and by up to 10.2%

14%

10.2%

respectively

for those with diameter of 10 mm.The damages of BFRP bars with diameter of 6 mm or 8 mm and the epoxy resin matrix interface were greater under coupled effects than those under single effect

but the influence is not obvious for bars with diameter of 10 mm.The elastic modulus of BFRP bars with three different diameters is 46.2 ±1 GPa under the natural environment

while it became 46.5 ±1.5 GPa under the condition of acid solution

freeze-thaw cycles and coupled effects.Under the influence of above environmental factors

the variation of elastic modulus of BFRP bars with three different diameters reinforced is 0.44%—1.67%.BFRP bars with three different diameters have a certain precision with respect to the Lemaitre strain equivalence principle under freeze-thaw cycles.