Properties of Fine-Grained Concrete with Admixture of Diatomite Powder

Abstract

The paper reports on the experimental assessment of the physical properties of fine-grained cement-based composites whose composition was enriched with admixture of diatomite powder. Diatomaceous earth, due to its origin and availability, represents highly valuable low cost material that can dispose with high pozzlanic activity. On this account, it can help to mitigate the quantity of used Portland cement, and thus enable to reduce the cost of produced cement-based composites, and accordingly decrease harmful environmental impacts of cement production, especially CO2 emission. In this work, possible use of diatomite powder as partial Portland cement replacement in concrete compoistion was studied. The cement replacement ratio was 5 %, 10 %, 15 %, and 20 % by volume. Reference concrete mixture was prepared as well. The water/binder ratio was 0.5, and was kept similar for all prepared composite mixtures. For 28 days water cured samples, bulk density, specific density, strength parameters, and thermo-physical properties were tested. Results of experimental analysis showed high pozzolanic activity of diatomite resulting in reduced porosity and increased mechanical resistance of the developed concretes. The highly porous structure of diatomite particles helped to decrease concrete heat transport properties, despite of low total open porosity of the tested specimens.