Hydraulics of grouts

Conclusions

• 1. Automatic recording of the hydraulic parameters of grouts makes it possible to obtain qualitatively new data on the character of flow of grouts. In particular, it is possible to record the character of occurrence of thixotropic properties during flow of grouts.

• 2. The regularity of the flow of viscoplastic thixotropic fluids is analogous before and after rupture of the thixotropic bonds, but differs in the magnitude of the static shear stress. The time of rupture of the thixotropic bonds depends on the loading rate, and after their rupture an abrupt decrease in the pressure difference occurs.

• 3. To describe the flow curves of grouts it is necessary to know the viscosity and values of the static shear stresses characterizing the sensitivity of the grout at rest and after its mixing, and also the relaxation time of grout during unsteady flow.

• 4. The relations obtained between the hydraulic characteristics of the flow of grouts in a pipe and in a slit permit converting from the characteristics of flow in pipes to that in slits and vice versa.

The rheological characteristics of grouts determined in a capillary viscometer with a circular and slit form coincide in magnitude.