GRANULOMETRIC COMPOSITION OF CEMENT AS A METHOD OF CONTROLLING CEMENT STONE PROPERTIES

The obtained data demonstrate the dependence of the frequency and amplitude of fluctuations in the compressive strength of cement stone on the granulometric composition of the cement. Using electron microscopy, it was found that the new formations in cement stone made from model coarse-grained cement have greater difficulty growing together into a monolithic conglomerate. Cement stone derived from predominantly coarsely ground cement, compared to stone from finely ground cement, gains strength more slowly. Strength fluctuations in the former occur with lower frequency and amplitude. At later stages of hardening, the strength values recover and increase after a temporary decline. Comparative X-ray phase analysis confirmed the accelerated hydration of fine cement fractions, leading to the formation of fine-crystalline structures prone to recrystallization. Due to recrystallization, cement stone made from finely ground cements is susceptible to cyclic decreases in compressive strength, without full recovery to its early maximum values. Based on the obtained data, to mitigate strength reductions and enhance the strength characteristics of cement stone at later hardening stages, it is necessary to ensure a balanced granulometric composition. This should include a complex mix of coarse (greater than 50 microns), medium (30–50 microns), and fine fractions in the cement.