Patent ID: 8551241
Filing Date: 2013-10-08
Classification: C04B,Y02W

Abstract:
1. A composition for preparing a lightweight cement board having increased compressive strength and water durability comprising a mixture of: water, cementitious reactive powder comprising: an alkali metal salt of citric acid as a set accelerator, up to 1.0 part of a secondary inorganic set accelerator, and lightweight aggregate selected from the group consisting of blast furnace slag, volcanic tuff, pumice, expanded clay, shale, and perlite, hollow ceramic spheres, hollow plastic spheres, expanded plastic beads and mixtures thereof; wherein the weight ratio of water to cementitious reactive powder is about 0.17 to 0.35:1.0, wherein the formed mixture has a compressive strength measured after 3 hours of between 2000 psi to 5000 psi (13.8 MPa to 34.5 MPa); and wherein the cementitious material is settable within 4 to 6 minutes of mixing of the composition without addition of a setting retarder.