Polycarboxylate Polymer Modified Cement Grout and Grouted Sand Behavior-Paper

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The study investigates how polycarboxylate ether (PCE) polymer affects cement grout rheology and the strength of grouted sand. Ordinary Portland cement grouts containing up to 0.16% PCE by cement weight were tested at water-to-cement ratios (w/c) of 0.6 and 1.0, at 25°C and 50°C. Three sands with different particle-size distributions were grouted, and compressive behavior was assessed after curing.<br /><br />PCE addition increased grout yield stress, apparent viscosity, and plastic viscosity, with the magnitude depending on polymer content, w/c, and temperature. At the maximum dosage, reported increases ranged from 15% to 136% for yield stress, 32% to 319% for apparent viscosity, and 58% to 367% for plastic viscosity. Raising the temperature also increased these rheological measures, while increasing w/c reduced viscosity. PCE further affected setting time.<br /><br />Compressive strength increased with PCE content and curing time, but also depended on the water-to-cement ratio, temperature, and sand type. The study attributes strength improvement partly to cement-particle dispersion and stronger bonding between particles. Differences in sand grading influenced grout penetration and the resulting strength.<br /><br />The researchers used the Vipulanandan p-q model to predict the stress–strain behavior of grouted sand and compared its predictions with the Wang model. Overall, the findings show that PCE can substantially modify grout flow and improve the mechanical performance of grouted sands, although outcomes depend on mix design and soil characteristics.

Keywords

polycarboxylate ether

cement grout

rheology

yield stress

plastic viscosity

grouted sand

compressive strength

water-cement ratio

temperature effect

Vipulanandan p-q model