Views: 179 Author: Sam Lee Publish Time: 2019-03-07 Origin: Site
The technology evaluated six commercial grinding additives used in the production of Portland cement (ground in a ball mill at the laboratory stage). They tested all cement mixtures for initial and final setting times, consistency of standard paste, flow of traditional mortar, and compressive strengths after 2, 7, and 28 days. They found slight decreases in the initial and final setting times in the cases of TEA-containing grinding aids based on C3A reaction acceleration. However, they also found that the presence of TIPA as a grinding aid in cement mixtures increases the initial and final setting times by around 15%, acting as a retarder of hydration at early stages. The aim of the research by technology was to interpret the effectiveness of TEA on the grindability and set and strength behavior of Portland cement in laboratory ball and vibrating disk mills when adding 0.06% amount by weight to the cement. They concluded that the addition of TEA increased both initial and final setting times and decreased the compressive strength at 3-, 7-, and 28-day curing ages in both ball and vibrating disk mill-ground cement.
The engineer determined the effect of grinding aid (GA) additions on the variation of flow of cement pastes. Two types of GA were used in which the first one was amine-based GA composed of a mixture of TIPA and TEA and the second was glycol-based GA composed of DEG and MEG. The Blaine fineness or energy consumption (Ec) is set constant for the experiments. They found that the water demand was increasing continuously with GA concentration because of higher cement fineness at constant Ec. The setting times of cement reduced by increasing GA concentration with constant Ec. When Blaine was set fixed with higher GA concentrations, a gradual increase in setting times and a decreasing tendency in water demands were seemed.