| 摘要 |
PURPOSE:To inhibit whitening by curing hydraulic substance at artificial low evaporation velocity in such a range that whitening is not caused or vaporizing and curing the hydraulic substance until gelatinized water is made absent and carbonating the hydraulic substance by reaction of both CO2 substituted by vaporization of water and a whitening component. CONSTITUTION:Cement, aggregate, a water-reducing agent and water are mixed at the prescribed weight. The obtained hydraulic substance is placed in a formwork or thereon. Then, a whitening component of the inside is not migrated on the surface by curing the hydraulic substance at artificial low vaporization velocity in such a range that whitening is not caused. Air is replaced by slowly vaporized water and approached to the inside. The whitening component reacts with CO2, contained in the air and thereby dense CaCO3 is formed to the inside from the surface. Therefore, the hydraulic substance is made difficult water-absorption and secondary whitening is made difficult to be caused. Further, hydraulic substance is left to stand and cured until capillary water is made absent. When the hydraulic substance is vaporized and cured until gelatinized water is made absent, the whitening component of the inside is not migrated on the surface layer because gelatinized water is joined to gel. The hydraulic substance is carbonated in the inside and secondary whitening is made difficult to be caused. |
