Polycarboxylate and Polyphosphonate Toward Low-Viscosity Concrete

Advances in dispersants for concrete allow prominent enhancement of the fluidity and workability of concrete. Besides the conventional polycarboxylate, a variety of cement-dispersant polymers have been developed. Recent advances in the rheological characterization of concrete allow the investigation of the dispersant's effect on the rheology of concrete. Cement mortar and concrete incorporating a polyphosphonate and its blend with a conventional polycarboxylate are quantitatively evaluated in this paper. The blended polymers bring a lower spread in the channel flow test when the mortar samples at the same grade of the viscosity curve are compared to the conventional polycarboxylate. Additionally, incorporating the blended polymers can reduce the plastic viscosity of a low water-cement ratio (w/c) concrete at the same grade of slump flow.