Title:
The Effect of Draining Formwork Materials on the Durability of Concrete
Author(s):
J. Stark, H. M. Ludwig and U. Knaack
Publication:
Symposium Paper
Volume:
170
Issue:
Appears on pages(s):
1029-1048
Keywords:
Blast furnace slag; cements; deicing; durability; drains; portland cement;
scaling; supersulfated cement.
DOI:
10.14359/6866
Date:
7/1/1997
Abstract:
The effects of a new draining formwork material made from polypropylene fibres on the properties of concretes of different composition were determined. The cements used were portland cement, blast-furnace slag cement, and supersulphated cement. Besides, the addition of air-entraining admixtures, and the use of the draining formwork material were also modified. In addition to the compressive strength other parameters influencing the durability of concrete were examined, i.e. the microstructure of the concrete, gas permeability, imperviousness to water, chloride-ion penetration, depth of carbonation, air void parameters and the frost and frost-deicing salt scaling resistance. In fresh portland cement concrete the effect of the draining formwork material on the water/cement ratio was determined at various depths of the concrete. In some cases the parameters which are important for the evaluation of the durability of concrete structures were considerably improved. A particularly advantageous result is that even concretes containing cements rich in granulated slag and made without air-entraining admixtures may achieve a high frost-deicing salt scaling resistance when this formwork material is used. The use of a draining formwork material is to be recommended when the requirements on the durability of concrete are very high.