APPARATUS FOR CARBONATION CURING AND PROCESS FOR PRODUCING CURED CEMENT OBJECT WITH DENSIFIED SURFACE LAYER

摘要

An apparatus for carbonation curing is provided which can be kept at any desired carbon dioxide concentration exceeding 20%, preferably exceeding 30%. The apparatus for carbonation curing has a shielded space where a cured cement object is placed and shielded from the outside atmospheric environment. The shielded space is equipped with: a gas introduction opening which is connected to a carbon dioxide supply source through a gas flow rate regulation mechanism; and a gas discharge opening which is connected to the outside through a gas inflow prevention mechanism. The gas flow rate regulation mechanism and the gas inflow prevention mechanism can be switched so that the mode of controlling the internal atmosphere can be any of at least a 'gas replacement mode' and a 'stationary mode.' This apparatus is especially suitable for use in the carbonation curing of a cured object formed from a kneaded cement mixture containing low-heat portland cement and γC2S, the amount of the γC2S being 30±10 parts by mass per 100 parts by mass of the binder, and having a water/binder ratio of 35% or lower.