Strength and durability of polypropylene fiber reinforced grouts

Fibrillated polypropylene fibers were added to cementitious grouts to determine whether improved mechanical properties and durability could be achieved. The grouts were studied for suitability as subsurface containment barriers around stabilized hazardous waste landfills. Strength, wet-dry and freeze-thaw durability and shrinkage crack control were investigated. Fibers added at volume fractions of 0.1 and 0.2% were found to reduce crack widths of restrained shrinkage specimens by bridging action. Compressive and flexural strengths were not consistently affected by incorporation of fibers. Fibers did not significantly change the residual compressive strength of air entrained grouts subjected to freeze-thaw cycles. Cementitious grouts are being evaluated for subsurface containment barriers around a chemical waste landfill at Sandia National Laboratories in New Mexico as part of the Mixed Waste Landfill Integrated Demonstration