The purpose of the thesis was to study the manufacture of cement and the additives used in this process. The research was focused on the use of plasticizers, and on the methods of researching their adsorption. The aim was to find a way to measure adsorption on the surface of the Portland cement (CEM I) particle. Two commercial plasticizers were analyzed, as well as two new lignin-based plasticizers. The work was carried out for VTT Oy.

Literature was studied to define adsorption and to describe its isotherms, concrete production and the additives used in it. Then, On the basis of other reports, various methods to analyze the ability of plasticizer adsorption were investigated to form a method that combined the various steps from these reports.

Small cement paste samples were made by mixing water, cement, and plasticizer with each other. These paste samples were centrifuged. The centrifuged samples were separated by pipetting the liquid which was then filtered. The amount of unadsorbed plasticizer was measured by the UV spectrophotometer. Over 40% of commercial plasticizers with a dose of 1% adsorbed, and according to graphs, the adsorption would have continued. About 30% of the lignin-based plasticizers with a dose of 1% adsorbed, and the adsorption maximum were found.

The method used was easy and accurate. When analyzing the method, the dispersion was small for all phases, producing accurate results. The results behaved like the Langmuir isotherm. The results also revealed that the larger particle size was adsorbed more easily on the surface of the cement particle than the smaller ones.