ABSTRACT

Negative properties of concrete include the volume changes occurring during their solidification and hardening process. These deformations and cracks lead to reduction of the strength and durability of structures. The most important volume change of concrete is shrinkage resulting from the ongoing physical and chemical processes. The concrete with a high water to cement ratio is especially prone on the drying shrinkage. This article deals with the effects of Shrinkage Reducing Agents (SRA) in different volume dosages on the properties of cement pastes. The experimental study was based on the measurement of the shrinkage and the cracks of hardened cement pastes occurrence, while the dosage of SRA additives and water to cement ratios varied. In addition, the impact of SRAs on the compressive strengths at the age of 1 to 90 days was also observed. The consistency and the bulk density were monitored on fresh pastes. The achieved results have shown positive effects of SRA, but only to a certain extent.