Here is the full list of all 10 Bridge Constructor Stunts achievements.
Accumulate 1 hour of air time.
Gain 1000000 points through destruction.
Destroy 250 red explosive barrels.
Destroy the pickup truck 250 times.
Do 500 flips.
Collect 250 stars.
Do a 4x flip with the dump truck.
Collect 25 bolts.
Do a jump with 7 seconds of air time.
Do a 5x flip with the pickup truck.