To develop a high performance cement-based grouting materials and use it in complex stratum

the effects of sodium aluminate (SA)

superplasticizer (Sp)

super-absorbent polymer (SAP) and their dosage on rheological properties and bleeding of fresh cement paste were investigated. The hydration evolution of cement paste at early stage and suspension morphology of particles in different polymers system were also analyzed by heat monitoring and fluorescent inverted microscope. Results indicated that the flowability and bleeding of fresh cement paste negatively related to the dosage of SA and SAP

which were enhanced with the increase of Sp contents. The stage of hydration induction was delayed for about 1 h

then the rate of heat flow decreased significantly with the incorporation of Sp and SAP. Affected by the procoagulant of SA

the dispersion of Sp

and reservoir function of SAP

the period with high flowability (greater than 200 mm) of fresh cement paste could be controlled within 10 min

20 min

and 30 min respectively with a bleeding ratio lower than 5% (stable slurry). Then the rheological parameters suddenly increased while the fluidity sharply decreased. Combined with microstructure test results

the evolution model was established to reveal the rheological mechanism of dispersion-absorption-rheological-hydration at early stage affected by the synergetic effects of polymers system.