Aimed at the shortcomings and the applied limitation of the existing accelerators of concrete,a new type of accelerator has been developed.It is composed of the crystal seed,the high valence cation sulfate and hydroxycarboxylic.When the new accelerator is added into concrete,it will increase the early strength of concrete,reduce the slump-loss and bleeding,and decrease the shrinkage.The new accelerator has a good compatibility with cement.The effect of early strengthen is obvious at low temperature.The conc...