STRUCTURE FORMATION OF HYDRAULIC LIME IN THE PRESENCE OF A POZZOLANIC ADDITIVE

Abstract

The article presents data on the strength of samples based on hydraulic lime in the presence of the pozzolanic diatomite additive. It establishes that the replacement of hydraulic lime with diatomite increases the compressive strength at the age of 28 days of hardening in air-dry conditions. When 20% of hydraulic lime are replaced with diatomite, the compressive strength is 35 kgf/cm2, and when 10% are replaced with diatomite, this value is 30 kgf/cm2 . The pozzolanic strength index is 1.07–1.25 depending on the diatomite content. The differential thermal analysis method revealed a lower content of portlandite and calcite and a higher content of calcium hydrosilicate in the structure of samples with the addition of diatomite. The carbonation reaction of the samples based on NHL5 hydraulic lime has a higher rate at an early stage of hardening compared to the samples with the addition of diatomite.