Abstract
For the purpose to reduce the surface void of powder type self-compacting concrete, the effects of air content and fluidity, the types of form release agent are discussed in this paper.
Generally, the high-range water-reducing agents (SP) are classified for two types to adjust the air content. One of them is a type to annex the air entraining agent for Naphthalene type of SP, and anothor one is a type to annex the deformer agent for Poly-carboxylic acid type of SP.
The behavior of sinking coarse aggregate and rising air void were explained by the equilibrium of the forces of buoyancy, gravity, and fluidity resistance. Coarse aggregate and internal void is assumed a spherical solid body. The fluidity resistance of mortar is expressed by theological constants (yield value and plastic viscosity).
And, the separation of surface void from the form is showen to be possible to explain from the equilibrium of abovementioned force and adhesion to the form.
