Title: Development of Slump-Loss Controlling Agent with Minimal Setting Retardation

Author(s): D. Hamada, H. Sato, H. Yamamuro, T. Izumi, and T. Mizunuma

Publication: Symposium Paper

Volume: 217

Issue:

Appears on pages(s): 127-142

Keywords: concrete; setting retardation; slump-retention; superplasticizer

DOI: 10.14359/12910

Date: 9/1/2003

Abstract:
A new slump-loss-controlling agent was found that could control the slump retention time for more than 90 minutes with minimal setting retardation. This slumploss-controlling agent was based on the polyether-grafted polymer in which the specific monomers were co-polymerized. Although this agent did show weak initial dispersing ability of cement particles just after the addition to cement slurry, it was decomposed in the alkaline condition of the cement slurry and gradually enhanced its dispersing ability, which made long retention of dispersability possible. Utilizing the technology of long polyether-grafted chains, which was previously reported to be very effective to disperse cement particles by steric repulsion, high dispersing retention ability with lower dosage and minimal setting retardation could be achieved. This slump-loss-controlling agent has already been used successfully worldwide. This technology will bring various possibilities and merits in concrete construction field such as shortening the construction period.