Wastepaper fibres in cement products

Wastepaper is an acceptable reinforcement for cement products. At fibre loadings of approximately 12% by mass the air cured cement composite has flexural strength of 18.2 MPa, fracture toughness value of approximately 1.0 kJ/m², water absorption value of 25% and a density of 1.43 g/cm³. Quality wood fibre reinforcement (P. radiata kraft pulp) provides similar values of water absorption and density but has superior values of flexural strength (28 MPa) and fracture toughness (2.3 J/m²) at similar fibre content (12% by mass). The cost of wastepaper is, however, only 15–25% that of P. radiata kraft pulp and for certain applications must have an economic advantage over the more expensive kraft reinforcement.