Effects of Polypropylene Fibers on Preventing Concrete Spalling In Fire

Abstract

The addition of polypropylene fibers (PP-fibers) has been proved effective to prevent explosive spalling of concrete elements in tests. With PP-fibers, the permeability of concrete will increase significantly above the melting of PP-fibers, as a results, high pore pressure can be prevented. To investigate the effects, the permeability of concrete with PP-fibers has been measured. The effect on explosive spalling of concrete is investigated by experimental and numerical methods. Apart from the amount, the fiber geometry must be taken into account. For the PP-fiber combination investigated by fire test, the recommended amount by Eurocode 2 is effective for these thin PP-fibers. The test result has been simulated by a spalling model. The spalling model considers the influences from the combination of PP-fiber with a simplified increasing factor, the application of other types and amounts of PP-fibers can be evaluated by this model.