Abstract The impact of three different organosilicon compounds: poly(dimethylsiloxane) (PDMS), potassium methylsiliconate (MESI) and triethoxyoctylsilane (OTES), used as integral admixtures, on Portland cement hydration has been investigated by isothermal calorimetry DTA-TG analysis. silicon-based compounds are widely internal hydrophobic agents added into batch water; therefore, their effectiv...