INFLUENCE OF THE RECIPES ON THE STRENGTH OF STRENGTH OF GEOPOLYMER COMPOUNDS WHEN CEMENTING LRW

Abstract

The influence of the composition of geopolymer binders (blast furnace slag, removal ash, liquid glass and KOH) on the properties, namely the compressive strength of the compounds formed during LRW cementation, is studied. To perform the work, compounds were made in which the masses of the components varied according to the plan of the factorial experiment in 23 – three factors on two levels. The factors chosen were: liquid glass, a mixture of slag with ash in a ratio of 1: 1 and potassium hydroxide. The mass of LRW imitation did not change in all experiments. The experiments were not duplicated, and the random error was assessed analytically. The calculations gave the equation that relates the compressive strength of the compounds to the mass of liquid glass, slag and ash, and potassium hydroxide. When constructing the equation, it was found that the variance of the batch of measurements by the Cochren’s criterion is homogeneous, the coefficients of the equation by the Student’s criterion are statistically significant, and the model (equation) by the Fisher criterion is adequate. The analysis of the equation showed that the strength limit is influenced by slag and ash, but the greatest influence is exerted by the pair interaction of liquid glass with ash and slag. The consequence of the interaction is the formation of a geopolymer network, which strengthens the compounds. The addition of potassium hydroxide reduces the strength of the samples due to excess potassium and sodium cations, for which there is no functional place (combination with Al atoms to change the electronic configuration to tetrahedral). For this case, an equation with a correlation coefficient R = 0.86 is obtained. The application of the method of steep ascent showed the possibility of increasing the strength limit by 1.5 times or more. In the future, it is planned to reduce the amount of ash in the binder or replace it with temperature-activated kaolin. Mechanical activation of the slag powder had a positive effect on increasing the compressive strength.