Title: Influence of the Aqueous Phase of Cement Paste on the Rheology in the Presence of PCE

Author(s): Wolfram Schmidt, Sarah Leinitz, Berta Mota, and Claudia Crasselt

Publication: Symposium Paper

Volume: 329

Issue:

Appears on pages(s): 429-444

Keywords: aqueous phase of cement paste; polycarboxylate ether; rheology; yield stress; plastic viscosity; heat of hydration; syngenite; solid volume fraction.

DOI: 10.14359/51711232

Date: 9/26/2018

Abstract:
The paper presents rheometric results and hydration curves for cementitious systems based on cement mixed with different aqueous phases at solid volume fraction of ϕ = 0.45. The varied aqueous phases were deionized water, limewater, the filter residue of a cement paste mixed at w/c = 2.0, and the filtrate of cement paste at solid volume fraction of 0.45. Each cementitious system provided different amounts and sizes of particles formed in the aqueous phase. The pastes were observed with and without polycarboxylate ether based superplasticizer. It was observed that the presence of particles causes higher PCE saturation dosages to achieve a minimum value, but the minimum value is only affected in the case of large particles. In all cases with and without PCE, the presence of small particles causes increased plastic viscosity. In addition, with decreased number and size of hydrates in the aqueous phase the hydration was retarded, which was specifically pronounced in the presence of PCE.