Study On Preparation And Application Of New Type Cement Grinding Aids

New types cement grinding aids were prepared by methods of modification of triethanolamine and synthesis of high polymers. Under grinding condition unchanged, it can improve greatly the fineness and strength of cement and can also reduce its dosage, achieving goals of improving the performance of cement and also reducing production costs.Firstly, the effect of modified-triethanolamine composite grinding aids on properties of cement was studied through modifying triethanolamine with acetic acid and maleic anhydride (MA) and through mixing with a variety of surfactants. It is found that effect of MA-TEA with dosage of0.06%o on properties of cement is best.45μm sieve fineness reduces7.6%than blank cement samples, the3d and28d compressive strength of cement mortar improves3.5MPa and4.8MPa respectively than that of blank cement samples. In addition, compared with unmodified-triethanolamine composite grinding aids, it has also better improvement on fineness and strength,and has lower dosage.Meanwhile, it also optimizes cement particle size distribution, making cement particles content of3-32μm improve significantly.Secondly, using APS as the initiator, a multifunctional macromolecule grinding aids was prepared through technical approach of free radical copolymerization of multiple. The experimental results show that it is best reaction condition when the dosage of AA, MA, MA-TEA, SMAS is respectively0.6,0.15,0.25,0.015mol, reaction temperature is75℃and initiator dosage is3.0%. And the effect of macromolecule grinding aids on cement performance is best.45μm sieve fineness reduces9.4%than blank cement samples, the3d and28d compressive strength improves4.4MPa and5.5MPa respectively than that of blank cement samples.Finally, micro-action mechanism of grinding aids was studyed by testing methods such as SEM and XRD. It is indicated by SEM and XRD that cement samples with MA-TEA composite grinding aids or macromolecule grinding aids samples have more hydration products and more fully degree of hydration compared with blank cement samples,which can improves the strength of cement mortar.