dc.description.abstract |
Cement is obtained by heating a mixture of limestone with iron oxide, aluminium oxide
and silicon oxides; and grinding the resulting clinker together with calcium sulfates and
slag, limestone, or fly ash depending on the cement type. In this study the effect of PCE on
cement grinding, compressive strength and water demand of treated cement has been
investigated. Response Surface Methodology (RSM) based on central composite design
(CCD) experiments was used to optimize process parameters for compressive strength and
water demand of mortar. A statistical model with the factor of PCE concentration and
blaine was developed using two-level CCD experiments with central and axial points. From
the analysis of variance, it was observed that both parameters have a significant effect on
compressive strength and PCE concentration has a significant effect on water demand
reduction of resulted cement. The maximum and minimum values of compressive strength
were 61.56 and 52.9 MPa respectively. The optimum results found to be compressive
strength of 60.92 MPa, PCE concentration of 0.15 %, and blaine of 3690 cm
2
/g for the
given cement type and composition.
The difference between R-squared and Adj R-squared is less than 0.2 in both cases. This
implies the experimental data is good fit at linear model for compressive strength and
quadratic model for the water demand. Since the experimental result is in accordance with
the model predicted value; it shows the reliability of the predicted model.
Keywords: Polycarboxlate Ether, Cement, cement/PCE composite, compressive
strength |
en_US |