Patent ID: 8333836

Claim:
A method of manufacturing a fiber reinforced cement composite material, comprising: providing cellulose fibers, wherein the cellulose fibers include bleached cellulose fibers having a Kappa number less than about 10, wherein the bleached cellulose fibers comprise less than about 40 wt. % of total cellulose fibers and are substituted for premium grade cellulose fibers from P. Radiata pine, wherein the bleached cellulose fibers are not from P. Radiata pine having an average tensile strength of more than about 12.5 km by TAPPI method T231; mixing the cellulose fibers with a cementitious component to form a fiber cement mixture; forming the fiber cement mixture into a shaped fiber cement article; and curing the fiber cement article to form a fiber reinforced cement composite material, wherein, with substitution of the bleached cellulose fibers, modulus of rupture of the fiber reinforced cement composite material when formed is maintained or improved as compared with a fiber reinforced cement composite material manufactured without the substitution for premium grade cellulose fibers.