The mechanochemical process and properties of Portland cement with the addition of new alkanolamines

Abstract

Grinding aids have been researched and used for decades to reduce energy consumption in the process of cement production. In this work, the effects of new alkanolamines, such as N,N-bis(2-hydroxyethyl)isopropanolamine (DEIPA), N,N-bis(2-hydroxypropyl)-2-aminoethanol (EDIPA) and N,N,N′,N′-tetrakis(2-hydroxyethyl)ethylenediamine (THEED), on the grinding, flowability and physical properties of Portland cement were investigated. The results indicated that DEIPA and EDIPA could significantly decrease the sieve residues (45μm), and improve the flowability of the cement powder. They could decrease the compressibility and the magnitude of the pressure drop of the cement at a definite normal stress, thereby preventing cement particles from agglomerating. Notably, DEIPA and EDIPA increased both the early (3-day) and late (28-day) compressive strengths. DEIPA can be used as an accelerator to shorten the setting time. THEED just provides a greater contribution to the late compressive strength.