max

ηm dx

where τ

– maximum tension; η – plastic viscidity of the

max

m

system with the maximum destructive structure; dV/dx – gradient

of speed of deformation during flow.

41

a

b

τmax

τmax

Fig. 2.1. Change of viscidly-plastic properties of concrete mixture

depending on tensions:

a – change of structural viscosity; b – change of speed of deformation of

flow (αo and αm – corners, which characterizing coefficients of viscosity of

the system);

τmax – maximum tension; ηo ηm – plastic viscosity of the system accordingly with

nondestructive and destructive structure

42

The conduct of concrete mixtures at vibration approximately can be

described by Newton formula :

dV

τ = η