Experimental investigation of the influence of the plasticizing agent on the properties of cement mortars

Abstract

Negative properties of concrete include the volume changes occurring during their solidification and hardening process. These deformations and cracks lead to reduce the strength and the 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 verification of the properties of cement mortars using selected kinds of plasticizing agents developed for self-levelling cement screeds. Applied agents (MS 3-12, MS 4-12, MS 5-12 and reference Berascreed 101) are based on modified polycarboxylates. The dosage of these agents was determined by the previous research in the amount of 1.5% by weight of the binder. The use of agents had a positive impact on the consistency of the fresh cement mortars and increased values of the initial and the long-term compressive strength. The negative impact of these agents was noted at the shrinkage and bulk densities of fresh and hardened cement mortars. Based on the achieved results can be concluded, that the plasticizing agent MS 4-12 may be considered a suitable substitute for the reference agent.