Abstract
This study utilized Ordinary Portland cement (OPC) and fly ash (FA) as primary cementitious materials andinnovatively introduced graphene oxide (GO) as a reinforcing and toughening agent to develop a novel andenvironmentally friendly fly ash-cement composite grouting material (FCGM). The influence of GO dosage onworking and mechanical properties of the FCGM was systematically investigated through single-factor experiments.Furthermore, microscopic analyses were performed to elucidate the mineral composition, chemicalstructure evolution, and microstructural characteristics of the hydration products. In addition, uniaxialcompression test (RMT) and scanning electron microscopy (SEM) were employed to evaluate the groutingeffectiveness in the coal gangue consolidation experiments. The results indicated that the incorporation of GOeffectively reduced the bleeding rate of FCGM. In contrast, the setting time, flowability, and compressive strengthof the hardened specimens initially increased and then decreased with increasing GO dosage. The FCGMexhibited optimal workability at a GO dosage of 0.01 %. Compared to the control group, the compressivestrength of the specimen increased by 27.1 % and 20.1 % at 3 days and 28 days, respectively. Microstructuralanalyses confirmed that GO promoted cement hydration and accelerated pozzolanic reaction of FA, therebyenhancing the formation of cementitious products and improving matrix crack resistance. Grouting reinforcementtests demonstrated that the cemented specimens exhibited significantly enhanced mechanical property at aGO dosage of 0.01 %. This enhancement in mechanical properties was attributed to the formation of a networklikecalcium silicate hydrate (C-S-H) gel, which reinforces the adhesion between the cementitious matrix andgrouting interface.
NETL
NSTL
Elsevier