Abstract
The performance of set-retarder on granulated blast furnace slag（GBFS）was evaluated quantitatively. The GBFS powder containing sodium gluconate as set-retarder was shaped and after that cured at various temperatures. The propagation time changing with curing was measured by means of the ultrasonic transmission method. The analysis of setting time obtained from setting behavior schematically was conducted, based on the adsorption of the set-retarder on the surface of the slag. As a result, the set-retardation performance of sodium gluconate was expressed with the adsorption isotherm of Langmuir-Freundlich type. The set-retardation time mainly depended on the content of sodium gluconate, and was not much affected by curing temperature.
