Form Filling with SCC in a Vertical Form: Results from Experiments

This paper presents the results obtained from two different vertical form filling experiments with SCC that have been completed as part of the experimental work in an ongoing Ph.D project. The project is carried out at the Danish Technological Institute in collaboration with the Technical University of Denmark and the second largest ready-mix manufacturer in Denmark, 4K-Beton A/S.

The aim is to identify the flow characteristic of SCC and the effect of concrete properties, casting technique, reinforcement configuration, and form geometry. A wall form of dimensions l = 3m, w = 0.3m, h =1m has been produced. To improve identification of the flow (i.e. dead zones, plug flow, laminar flow, turbulent flow, blocking etc.) the form has one transparent acrylic plate and it has shown valuable to change between normal greyish concrete, and a pigmented (red) concrete during the filling process.

Monitoring equipment has been produced and tested and is valuable as documentary evidence of the flow in combination with visual observations. In one experiment reinforcement gap sizes of 1.5 and 3⋅Dmax,agg have been applied and blocking occurred at 1.5⋅Dmax,agg. Pumping from the bottom corner at casting rate of 10 m/h resulted in hydrostatic pressure.

Continuously shearing across the surface seems to have a positive effect on the surface quality (no blowholes).