The effect of synthetic zeolite on viscosity of cement paste

Abstract

The paper reports the effect of the synthetic zeolite admixture on the viscosity of cement paste. Materials include Portland cement CEM I 42.5 R, synthetic zeolite obtained through low-temperature synthesis under laboratory conditions, polycarboxylate ester based supeplasticizer Muraplast FK 63.30 and tap water. Three compositions of cement paste were made adding 0%, 5%, and 10 wt% of synthetic zeolite. A rotating cylinder viscometer was used for measuring the consistence of the paste; viscosity was measured employing vibrational viscometer SV–10. The consistency test on cement paste showed that spread with no addition of synthetic zeolite made 149 mm, containing 5% of synthetic zeolite the slump was 85 mm and containing 10% of synthetic zeolite spread was 70 mm. The viscosity test also indicated that for the period of 30 minutes, changes in the viscosity of cement paste were as follows: 81.11 mPa s with no addition of synthetic zeolite, 746.5 mPa s containing 5% of synthetic zeolite and 827.1 mPa s containing 10% of synthetic zeolite. Data on the viscosity of cement paste were statistically processed applying software Statistica. Dispersion diagrams demonstrate changes in the viscosity of cement paste adding from 0 to 10 wt% of synthetic zeolite. Taking into account synthetic zeolite, the following correlation coefficients were calculated: 0% – 0.938, 5% – 0.967, 10% – 0.988. The coefficients of determination made 0% – 0,880, 5% – 0,935, 10% – 0,976. Equations for a dependent variable were produced by regression analysis.

Šio darbo tikslas – nustatyti, kokią įtaką cemento tešlos klampumui turi sintetinio ceolito priedas. Naudotos šios medžiagos: portlandcementis CEM I 42,5 R, sintetinis ceolitas, gautas laboratorijoje atliekant žematemperatūrę sintezę, superplastiklis Muraplast FK 63.30 multikarboksilato esterio pagrindu ir vandentiekio vanduo. Buvo maišomos trijų sudėčių cemento tešlos dedant 0 %, 5 %, 10 % sintetinio ceolito priedo nuo cemento masės. Cemento tešlos konsistencijai nustatyti buvo naudojamas Sutardo viskozimetras, klampumui – vibroviskozimetras SV-10. Atlikus cemento tešlos konsistencijos bandymą nustatyta, kad be sintetinio ceolito priedo cemento tešlos pasklidimas – 149 mm, su 5 % sintetinio ceolito priedu – 85 mm, 10 % – 70 mm. Nustačius cemento tešlos klampumą gauta, kad be sintetinio ceolito priedo cemento tešlos klampumas per 30 minučių kinta 81,11 mPas, su 5 % priedo – 746,5 mPas, 10 % – 827,1 mPas. Cemento tešlos klampumo tyrimo duomenys buvo statistiškai apdorojami kompiuterine programa „Statistica“. Šiame darbe pateikiamos sklaidos diagramos, kuriose pavaizduota, kaip kinta cemento tešlos klampumas laiko atžvilgiu naudojant sintetinio ceolito priedą nuo 0 iki 10 %. Nustatyti korealiacijos koeficinetai: 0 % – 0,9380, 5 % – 0,9669, 10 % – 0,9881, bei determinacijos koeficientai: 0 % – 0,8798, 5 % – 0,9348, 10 % – 0,9763. Atlikus regresinę analizę buvo gautos priklausomybių lygtys.