Synopsis
This paper describes the results of tests developed to study the rate of water uptake and the equilibrium water content of light weight concrete specimens treated with a variety of waterproofing techniques. The k value and compressive strength of the treated specimens were also determined. The Waterproofing techniques used were: surface sealants; integral sealants, both reactive and non-reactive; waterproofing aggregates; combinations of these last two; cured concrete specimens saturated with a silicone water-repellent solution; replacing cement by resin binders. Some of these techniques were much more successful than others. The least successful was the use of reactive integral sealants, which had no effect upon water uptake. Easily the most successful method was the substitution of resin binders for cement; with these, the equilibrium moisture content was reduced to about l% by volume or less compared with about 20–25% by volume for untreated materials. A substantial increase in compressive strength was also observed. This work indicates that an insulating material with low k value, an adequate compressive strength for use in an engineering environment and a low water equilibrium value will be resin-based rather than cement-based.
