The rheological curves of powder viscosity modifier admixture(VMA)combination type self compacting concrete(SCC)with different water powder ratios were determined by means of RHM 3000 ICAR rheometer. The data obtained were modeled by the Bingham model, Herschel Bulkley(H B) model and modified Bingham model respectively. The results indicate that the yield stress increases with increasing water powder ratio of the SCC with the same slump flow and air content, while the opposite is true for the plastic viscosity. The increasing water powder ratio can weaken the shear thickening behavior. When the water powder ratio increases to 0.40(by mass), the shear thickening phenomenon completely disappears, showing a shear thinning behavior. Both H B model and modified Bingham model can describe the shear thickening behavior of SCC, and the c/μ of modified Bingham model is more sensitive to shear deformation.
LI Huanjian,TAN Yanbin,XIE Yongjiang,et al.The characteristics of self compacting concrete and its application in high speed railway[J].Railway Engineering,2012(8):143 145.(in Chinese)
[4]FEYS D,VERHOEVEN R,de SCHUTTER G.Why is fresh self compacting concrete shear thickening[J].Cement and Concrete Research,2009,39(6):510 523.
[5]YAHIA A.Effect of solid concentration and shear rate on shear thickening response of high performance cement suspensions[J].Construction and Building Materials,2014,53(2):517 521.
[6]HEIRMAN G,HENDRICKX R,VANDEWALE L,et al.Integration approach of the Couette inverse problem of powder type self compacting concrete in a wide gap concentric cylinder rheometer:Part Ⅱ.Influence of mineral additions and chemical admixtures on the shear thickening flow behavior[J].Cement and Concrete Research,2009,39(3):171 181.
[7]de LARRARD F,FERRARIS C F,SEDRAN T.Fresh concrete:A Herschel Bulkley material[J].Materials and Structures,1998,31(7):494 498.
[8]YAHIA A,KHAYAT K H.Analytical models for estimating yield stress of high performance pseudo plastic grout[J].Cement and Concrete Research,2001,31(5):731 738.
[9]FEYS D,VERHOEVEN R,de SCHUTTER G.Evaluation of time independent rheological models applicable to fresh self compacting concrete[J].Applied Rheology,2007,17(5):1 10.
XIE Youjun,CHENG Xiaobo,MA Kunlin.Effects of fly ash on shearing thinning and thickening of cement paste[J].Journal of the Chinese Ceramic Society,2015,43(8):1040 1046.(in Chinese)
[11]CYR M,LEGRAND C,MOURET M.Study of shear thickening effect of superplasticizers on the rheological behavior of the cement pastes containing or not mineral additives[J].Cement and Concrete Research,2000,30(9):1477 1483.
[12]HEIMAN G,VANDEWALLE L,van GEMERT D,et al.Time dependent deformations of limestone powder type self compacting[J].Engineering Structures,2008,30(10):2945 2956.
[13]WALLEVIK J E.Relationship between the Bingham parameters and slump[J].Cement and Concrete Research,2006,36(7):1214 1221.
[14]ROUSSEL N.Correlation between yield stress and slump:Comparison between numerical simulations and concrete rheometers results[J].Materials and Structures,2006,39(4):501 509.
[15]YAHIA A.Shear thickening behavior of high performance cement grouts—Influencing mix design parameters[J].Cement and Concrete Research,2011,41(3):230 235.
[16]HOFFMAN R L.Explanations for the cause of shear thickening in collodial suspensions[J].Journal of Rheology,1998,42(1):111 123.
[17]BRADY J F,BOSSIS G.The rheology of Brownian suspensions[J].The Journal of Chemical Physics,1989,91(3):1866 1874.
[18]FEYS D,VERHOEVEN R,de SCHUTTER G.The mechanisms behind shear thickening behavior of fresh self compacting concrete[C]∥3rd International RILEM Symposium on Rheology of Cement Suspensions such as Fresh Concrete.Bagneux:RILEM Publications,2009:105 112.