Methods of manufacturing cement products

Abstract

This study describes a method for producing cement preparations in which carbon dioxide is fixed. This method allows for a reduction in the reaction time of cement and carbon dioxide and a large amount of carbon dioxide to be fixed in the cement preparation. The method for producing cement preparations uses cement, aggregate, and water. This method includes: step (A) mixing one part cement and one part water to obtain a cement paste with a water-to-cement ratio of 250% or greater; Step (B) exposes the cement paste to carbon dioxide gas to obtain a carbonized paste; Step (C) separates some water from the carbonized paste to obtain a concentrated paste with a liquid-to-solid ratio of 80% to 400%; Step (D) mixes the concentrated paste and the remaining cement to obtain a highly concentrated cement-containing product; Step (E) involves mixing a highly concentrated cement-containing preparation and some remaining water to obtain a cement preparation, and is set up so that aggregate is supplied in any step, one or both steps in step (D) and step (E).