Patent ID: 8383031

Claim:
A method of modifying the properties of a low or medium density FRC, fiber reinforced cement, product comprising: applying a density modifier to a low or medium density FRC product having a density from about 1.2 to 1.6 g/cm 3 , wherein the density modifier reduces the density of the low or medium density FRC product to between about 0.8 to 1.1 g/cm 3 ; densifying said low or medium density FRC product to a density of no greater than about 1.6 g/cm 3 , wherein densifying the low or medium density product comprises applying a light press comprising applying about 5 to 40 MPa to the cementitious matrix with a ramping cycle between 10 to 40 minutes and a holding cycle of between 15 to 30 minutes; and curing said low or medium density FRC product, wherein the cured low or medium density FRC product has a predetermined pore size distribution such that in particular critical zones of said distribution, the pore volume is substantially equivalent to or less than the pore volume in a respective critical zone of a conventional high density FRC product.