Air management in cementitious mixtures having plasticizer and a clay-activity modifying agent

• Main Authors: JEKNAVORIAN ARA A, HILL CHRISTON L, OU CHIAIH
• Format: Patent
• Language: English
• Published: 24.07.2003
• Edition: 7
• Subjects: ARTIFICIAL STONE; CEMENTS; CERAMICS; CHEMISTRY; COMPOSITIONS BASED THEREON; COMPOSITIONS OF MACROMOLECULAR COMPOUNDS; COMPOSITIONS THEREOF, e.g. MORTARS, CONCRETE OR LIKE BUILDINGMATERIALS; CONCRETE; LIME, MAGNESIA; METALLURGY; ORGANIC MACROMOLECULAR COMPOUNDS; REFRACTORIES; SLAG; THEIR PREPARATION OR CHEMICAL WORKING-UP; TREATMENT OF NATURAL STONE; USE OF INORGANIC OR NON-MACROMOLECULAR ORGANIC SUBSTANCES ASCOMPOUNDING INGREDIENTS

An exemplary surface active agent admixture composition of the invention comprises (1) a first surface active agent comprising a betaine, an alkyl or aryl or alkylaryl sulfonate, or mixture thereof; and (2) a second surface active agent comprising a nonionic oxyalkylene-containing polymer surfactant. The present invention therefore provides a system for ensuring the presence in a hydratable cementitious composition (when hardened) a sufficient air volume and sufficient air void fineness and consistency. Further exemplary admixture compositions may comprise one or more plasticizers and one or more clay activity-modifying agents. Cementitious compositions and methods for modifying cementitious compositions, which incorporate the above-mentioned surface active agent combination, are also described. The invention provides the ability to adjust and stabilize air void systems in hydratable cementitious compositions, while allowing conventional air entraining agent (AEA) dosage practices to be followed.