Concrete based on low-strength carbonate rocks

Abstract

The patterns of formation of the main technical and operational characteristics of concrete produced on the basis of carbonate rocks and modified with various chemical additives have been established. The study considered the effect of the superplasticizer Glenium®51 and the hydrophobic-plasticizing additive SDO on the properties and performance characteristics of concrete mixtures and hardened concrete. The influence of the additives on the workability of concrete mixtures, strength characteristics, frost resistance, and the consumption of coarse aggregate and cement was investigated.
When using the SDO additive, the gravel content in the concrete compositions ranged from 0.9 to 0.7 m³. It was established that the introduction of an optimal amount of the SDO physicochemical modifier, equal to 0.03% of the cement mass, into vibroconcrete compositions with a cement content of 350 kg/m³ makes it possible to obtain concrete with a compressive strength of 35 MPa and a frost resistance grade of F150. The obtained results indicate that the optimal dosage of the SDO modifier for concrete compositions with a cement content of 350 kg/m³ is 0.03% of the cement mass, which ensures the required combination of strength and frost resistance characteristics.
It has also been established that concrete compositions containing the Glenium®51 superplasticizer make it possible to obtain concrete with a compressive strength of 35 MPa using vibration-free technology. The use of the superplasticizer contributes to improving the technological properties of the concrete mixture and provides the required strength characteristics without the need for vibration compaction. When the gravel content is reduced to 0.3–0.4 m³ per 1 m³ of concrete, the introduction of carbonate filler makes it possible to reduce cement consumption while maintaining the required performance characteristics of the concrete.
The conducted research made it possible to establish the optimal parameters of concrete compositions based on carbonate rocks, reduce the content of coarse aggregate, and optimize cement consumption. The obtained results confirm the effectiveness of using chemical modifiers and carbonate fillers for the production of concrete with improved technical and operational characteristics and contribute to the more efficient use of local raw materials in concrete production.