초록 ▼

A method and apparatus for continuous production of a quick-setting foamed cement grout, in which the individual constituents of the grout are proportionally adjustable. Finished foam and cement slurry are mixed at metered rates to form a foamed cement grout which is pumped to a wye connection proxi

A method and apparatus for continuous production of a quick-setting foamed cement grout, in which the individual constituents of the grout are proportionally adjustable. Finished foam and cement slurry are mixed at metered rates to form a foamed cement grout which is pumped to a wye connection proximate a remote injection site. Sodium silicate solution is added at the wye connection at a metered rate, using a second metering pump. The sodium silicate solution mixes with the foamed cement grout to greatly accelerate the setting time thereof, and compressed air may also be added to accelerate the passage of the material through the injection hose and nozzle. The quick-setting material is particularly suited for use with a tunnel boring machine (TBM), to grout the annular cavity between the tunnel bore and the segmented liner which is installed therein.

대표청구항 ▼

[ What is claimed is:] [1.] Apparatus for forming a flow of quick-setting foamed cement grout, said apparatus comprising:means for providing a flow of finished foam material at a metered rate;pump means for mixing said flow of finished foam material with a flow of cement slurry which is received by

[ What is claimed is:] [1.] Apparatus for forming a flow of quick-setting foamed cement grout, said apparatus comprising:means for providing a flow of finished foam material at a metered rate;pump means for mixing said flow of finished foam material with a flow of cement slurry which is received by said pump means at a metered rate, so as to entrain air therein and thereby form a viscous, low shear-strength foamed cement grout which is discharged from said pump means, said finished foam being added to said cement slurry in an amount sufficient to provide said foamed cement grout with a viscosity which is sufficiently high to minimize flow of said grout through and out of a void prior to a predetermined initial set of time of said grout; andmeans for adding a flow of sodium silicate solution to said flow of foamed cement grout downstream of said pump means so as to form said quick-setting foamed cement grout, said sodium silicate solution being added at a metered rate selected to accelerate hardening of said quick-setting foamed cement grout to said predetermined initial set time.