Effect of MgO additive on the specific conductivity of portland cement paste : master thesis

U ovom radu provedeno je određivanje specifične električne provodnosti cementnih pasti bez dodatka, te uz dodatak 5 mas. % i 10 mas. % MgO. Ispitivan je utjecaj dodatka MgO na pojavu maksimuma specifične električne provodnosti cementnih pasti. Mjerenja su provedena u termostatu pri 20 ⁰C i pri vodocementnom V/C = 0,5 i voda/kruto omjeru, V/K = 0,5. Sve dobivene krivulje ovisnosti specifične električne provodnosti o vremenu hidratacije pokazuju sličan oblik s naglašenim maksimumom specifične električne provodnosti. Iz rezultata se može zaključiti da čisti portland cement ima najveću vrijednost specifične električne provodnosti koja iznosi 18,22 mS cm -1 , dok dodatak prirodnog i sintetskog MgO uzrokuje pad specifične električne provodnosti.In this paper, the determination of the specific electrical conductivity of the cement pastes was carried out without the addition and with addition od 5 wt. % and 10 wt. % MgO. The effect od MgO addition on the appearance of the maximum soecific electrical conductivity of cement pastes was examined. The measurements were carried out in the thermostat at 20 ⁰C and at the water/cement ratio, W/C = 0.5 and water/solid ration, W/S = 0.5. All obtained curves of specific electrical conductivity dependence on the hydration time of the cement paste show a similar shape with a pronounces maksimum of the specific electrical conductivity. From the results it can be concluded that pure portland cement has the highest value of specific electrical conductivity which is 18.22 mS cm -1 , while the addition of natural and synthetic MgO causes a decrease of specific electrical conductivity. Samples with the addition of MgO have the appearance of a maximum of specific electrical conductivity in earlier hydration times