Maltitol-Derived Sacrificial Agent for Enhancing the Compatibility between PCE and Cement Paste.

Area of Science:

• Materials Science
• Civil Engineering
• Concrete Technology

Background:

• Clay in concrete interferes with polycarboxylate ether (PCE) adsorption onto cement particles, reducing slurry workability.
• This interaction limits the effectiveness of PCE superplasticizers in clay-rich cementitious materials.

Purpose of the Study:

• To develop and evaluate a novel sacrificial agent (SA) to improve PCE compatibility and performance in clay-containing cement slurries.
• To investigate the mechanism by which the SA enhances the dispersion and fluidity of cement pastes with clay.

Main Methods:

• Synthesis of a maltitol-ammonium salt cationic (KN-lm) sacrificial agent.
• Assessment of KN-lm's effect on the fluidity of clay-containing cement paste.
• Analysis using Total Organic Carbon (TOC), X-ray Diffraction (XRD), and zeta potential measurements.

Main Results:

• KN-lm significantly increases the initial fluidity of clay-containing cement slurry by approximately 19%.
• KN-lm preferentially adsorbs onto clay particles via electrostatic interactions, preventing PCE adsorption onto clay.
• No crystal structure changes were observed in clay, and cement particle dispersion was improved.

Conclusions:

• Maltitol-ammonium salt cationic (KN-lm) acts as an effective sacrificial agent for cement slurries containing clay.
• KN-lm enhances PCE compatibility with clay-containing cement, improving fluidity and dispersion.
• The preferential adsorption mechanism of KN-lm effectively hinders clay hydration expansion and PCE intercalation.