In this thesis the influence of internal curing on the compressive strength of high strength concrete was examined. Such concretes have much higher compressive strength than conventional concretes, so they can withstand the same load with a smaller cross-section of the element. However, since the high compressive strength is ensured primarily by the low water-cement ratio, these concretes are subject to greater shrinkage and consequently, cracks. Early shrinkage deformation can be greatly alleviated by the internal curing of the concrete, by means of internal water reservoirs, which in turn may adversely affect the compressive strength of the concrete.
An experimental study was conducted in which the phenomenon of internal reservoirs in high strength concrete was tested and analyzed. As an internal water reservoir we used pre-soaked natural tufa aggregate, pre-soaked artificial lightweight Liapor aggregate, pre-soaked basalt fibers and pre-soaked cellulose fibers. Internal water reservoirs were placed in concrete by replacing part of a conventional unit with a pre-soaked medium. We found that pre-soaked lightweight aggregate, natural and artificial, gave concrete a higher compressive strength compared to non-lightweight aggregate concrete, and placement of pre-soaked basalt and presoaked cellulose fibers had a negative effect on the compressive strength of concrete.