Simple field tests to characterize fluidity and washout resistance of structural cement grout

摘要: The ability to assess rheological properties of neat cement grout, such as those used in structural repair and for filling post-tension ducts, is special interest the evaluation ease pumping, spreading into place, narrow spaces. There an increasing need identify dependable simple test methods that can characterize consistency specialty grouts reflect variations during handling placement. Several tests be evaluate characteristics a grout suspension, including precise determination parameters procedures fluidity. Rheological accurately determined by using coaxial cylinder viscometer. However, use viscometer mainly limited laboratory, mini-slump spread modified Marsh cone are usually employed field verify quality control. This paper attempts establish relationships between fluidity values obtained methods. Relationships also wash-out resistance various parameters. derived based on wide variety covering up 210 data points. were prepared with W/C ranging 0.30 0.50, Type I III portland cements, well silica fume replacement (up 8% mass), blast-furnace slag contents 20 60%, fly ash substitutions 10 30%, limestone filler replacements 30%. investigated incorporated melamine- naphthalene-based high-range water reducer, welan gum cellulose-based viscosity-modifying admixtures, set-retarding admixture. Test results highlight difficulties relying single empirical given grout. Correlations measurements mass loss apparent viscosities at different shear rates indicate correspond low-shear (5.1 s-1). In contrast, measurement corresponds viscosity high-shear 340 510 s-1. Because pseudo-plastic behavior grouts, control should include assessment low high adequately grouts.