Polypropylene fibres within concrete with regard to heat induced spalling and reduction in compressive strength

The paper examines the effect of various polypropylene fibre additions (Types 1 and 2 and different fibre volumes) to concrete with regard to explosive spalling when subject to high temperatures similar to that experienced in building or tunnel fires. The pilot study used to determine an appropriate heat source for the test showed concrete to be a significant insulator and fire protection for structural members. Explosive spalling was shown to be reduced with the use of polypropylene fibres but the final compressive strength of concrete was significantly reduced and had little residual structural value after a 2 hour period of heating.