Effect of polymers on cement hydration: A case study using substituted PDADMA

A study was carried out, using heat flow calorimetry and quantitative X-ray diffractometry, of the different influences which are exerted by types of cationic Polydiallyldimethylammonium (PDADMA) displaying different anionic counterions on the hydration behavior of an Ordinary Portland Cement (OPC). It was shown that the influence of the cationic polymer PDADMA on the hydration of the cement will tend to be strongly dependent on the nature of the anionic counterion. In case of OH−, more calcium sulfate will tend to be dissolved in the early stages, which acts in turn as an accelerator for the hydration of the C3S phase. In case of SO42- there will tend to occur a secondary gypsum precipitation, which will in turn act to lower the Ca2+ – content in the mix water, leading to a retardation of the hydration process compared to the hydration in absence of polymer.