METHOD FOR CONTROLLING A WORKABILITY PARAMETER OF A CONCRETE IN A MIXER

摘要

A method for controlling at least one workability parameter of a concrete contained in the container of a mixer with a non vertical rotational axis, includes making the container turn at at least two different rotational speeds; determining, for each of the rotational speeds, a rotary drive torque C of the container, a value of shear stress τ of the concrete and a speed gradient value {dot over (γ)} of the concrete according to the following relationships:;τ=T(ω)·C ;{dot over (γ)}=G(ω)·ω;where T and G are predetermined functions;
determining a relationship of variation of the shear stress τ according to the speed gradient {dot over (γ)} by extrapolation and/or approximation based on the determined values; andproviding an indication of the workability parameter of the concrete based on the relationship of variation.

主权项

1. A method for controlling at least one workability parameter of a concrete contained in a container of a mixer with a non vertical rotational axis, comprising:
making the container turn at at least two different rotational speeds ω; determining, for each of said at least two rotational speeds ω, a rotary drive torque C of the container, a value of shear stress i of the concrete and a value of speed gradient {dot over (γ)} of the concrete according to the following relationships:
τ=T(ω)·C {dot over (γ)}=G(ω)·ωwhere T and G are predetermined functions;
determining a relationship of variation of the shear stress τ according to the speed gradient {dot over (γ)} by extrapolation and/or approximation based on the determined values; and providing an indication of the workability parameter of the concrete based on the relationship of variation.