It was carried out a study on the properties of polymer modified concrete (PCM) in fresh and hardened state. It was used three types of polymers: epoxy resins, polyurethane and methylcellulose in different percentages and different water cement ratio.The main objectives was to improve workability and rheological behavior of these mixtures in fresh state and mechanical strength tests on hard concrete. Has been investigated the polymer influence on compression strength and flexural strength and analyzing the time evolution of these strengths and participation of polymer in the microstructure formation.

The paper shows the constituents and technical properties of low calcium aluminates cement concretes with ultra dispersed mineral powders and admixtures.

The paper shows the possibility to utilize, for manufacturing of concrete with aluminous cement, the clay or silicon carbide waste aggregates resulting from demolition of linings, concomitantly with the decrease of cement content by using of the cheap admixtures.

The article presents a comparative analysis on the hydration of cement paste without superplasticizer and water/cement ratio of 0.35 and a cement paste with the same water/cement ratio but has in its composition 2% superplasticizer additive Glenium Sky 526. For characterizing the hydration process of cement paste, both mixtures were subjected to X-ray diffraction and thermogravimetry analysis, at 3, 7, and 28 days passed since the initiation of hydration process.

Abstract.