| 配制方法： |
100 grams of Portland cement is mixed dry with 200 grams of sand and 400 grams of 1/2-3/4" rock aggregate. This is then prepared as a heavy slurry in water. A dispersion of 10 parts of carbon black in 15 parts of dimethyl slufoxide is prepared on a small laboratory mill. Ten grams of this dispersion is diluted with 10 ml of water containing 0.2 gram solids of a set-control agent, i.e. a ligninsulfonate derivative. The diluted dispersion is added to the concrete slurry. The slurry is allowed to set, then is broken and excellent distribution of color is noted throughout the mass. |