Feasibility of using polyurethane waste in the form of granules for civil construction
Résumé
This paper investigates the feasibility of using industrially treated polyurethane waste in the form of granules (PUG) in substitution of sand for civil construction (blocks for load or non-load bearing walls, screed). Different PUG amounts were introduced into the cement-based mortar. The results show that 10 wt% PUG strongly reduces the workability and the mechanical strength (at 2 and 7 days) compared to a standard mortar (0 wt% PUG) due to the hydrophilic character of PUG. The mixture with 5 wt% PUG which performs better than 10 wt% PUG was optimized on the basis of workability and early age mechanical strength. It is found that among the tested parameters (superplasticizer (S) at different dosages, PUG pre-saturation, water addition, limestone), adding 1.5 wt% S gives the best performances. At 28 days, 5 wt% PUG with 1.5 wt% S reduced the mechanical strength (32 MPa and 6 MPa, respectively in compression and bending compared to 55 MPa and 9 MPa for the standard mortar) and increased the shrinkage. The dry density and the thermal conductivity were reduced respectively by 9% and 10%, which can be interesting for both off-site construction and plastic waste or mineral resources management.