Re-Use of GRP Industrial Waste in Cementitious Products

The feasibility of re-using GRP industrial waste to produce blended cements was investigated. Firstly, the waste material was characterized and then it was added to standard mortars as cement replacement at dosage rates of 10% - 20% - 40% by cement weight. The addition appeared chemically compatible with cement and GRP could replace up to 15% by weight of the cement in order to assure the mechanical strength threshold prescribed by actual cement standards. The new "GRP blended cements", even if showing significantly lower volumic mass and mechanical strength, seem to be able to confer higher deformability to the cementitious products manufactured by them. Moreover, since the GRP waste did not show any binding capacity, the addition lead to an increase in the water/cement, thereby raising the porosity of the manufactured elements. However, unexpectedly, capillary water absorption and drying shrinkage of these elements resulted lower than those of the reference mortar without any GRP addition, showing in this way enhanced durability.