Abstract:
This paper studies the threaded polypropylene bar as the connecting piece to line the
polypropylene waterproof plate inside concrete segment. The polypropylene bars are
welded to the polypropylene waterproof plate so that the polypropylene waterproof plate
and the concrete segment can be cast together to achieve high-efficient waterproofing.
The bonding properties between polypropylene bar and concrete have been tested. A pullout test including 16 pull-out specimens composed of concrete cube block and
polypropylene bar was conducted under pull-out loading. The parameters included surface
type and diameter of polypropylene bar and concrete strength grade. Test results show
that the maximum bond strength between polypropylene bar with threads on the surface
and concrete reaches 3.14MPa, which is 12.8 times stronger than polypropylene bar with
smooth surface. The bond strength between polypropylene bars with a diameter of 30mm
has doubled strength than polypropylene bars with a diameter of 25mm. The concrete
strength has no significant effect on the bond strength. 3D model of pull-out specimens
was established in simulation software ABAQUS. The bonding connection was performed
by utilizing the non-linear spring elements. The results display that the stress distributed on
concrete starts to radiate from the bonding interface to the surroundings in a dumbbell
shape and gradually decreases. The stress distribution on polypropylene bar gradually
decreases from the loaded end to the free end. The deviation between calculated value
and test value within anchoring range 14%. The finite element model can closely reflect
bond-slip characteristics between polypropylene bar and concrete.
