THE EFFECT OF SURFACTANTS ON GRINDING AND HARDENING THE PORTLAND SLAG CEMENT CONTAINING HIGH BLAST FURNACE SLAG PROPORTIONS

The paper presents the investigation regarding the effect of surfactants on the specific energy consumption in grinding and on the mechanical characteristics of cement with high blast furnace slag content. Moreover, information regarding the influence of the processing technique of high blast furnace slag cement on cement's properties is disclosed. The surfactants were from the amino alcohol class, the difference between them being the length of concatenation of the hydrocarbon. The surfactants-monoethanolamine (MEA) and triethanolamine (TEA)-were used in ratios of 0.03%, 0.05%, and 0.1%. The obtained cement was ground up to a fineness expressed as Blaine specific surface area of approx. 4500 cm(2)/g. As reference cement, Portland cement without any addition was employed. It was found that for grinding the blast furnace slag and the Portland composite cement with 20% and 80% blast furnace slag, respectively, without any surfactant, the energy consumption was lower than for the ordinary Portland cement. A significant decrease in energy consumption for grinding the ordinary Portland cement. The type and optimal proportion of surfactant varies with the cement sort. In the case of ordinary Portland cement and Portland composite cement with 20% blast furnace slag, the best effect was noticed when using MEA, while in the case of grinding the blast furnace slag and the Portland composite cement with 80% blast furnace slag the best effect was noticed when using TEA. An analysis of the effect of the surfactants upon hardening has revealed a difference in the mechanical behaviour of the cement interground with surfactants as compared to the reference cement. The presence of intergrinding surfactants in both reference cement and Portland composite cement with low addition of blast furnace slag led to slight decreases of the compressive strength. However, the use of TEA in intergrinding the cement with a high proportion of blast furnace slag led to slightly increased compressive strength values as compared to the reference cement.