Project leader, Division of Building Technology, CSIR, Pretoria,
Swelling clay and rock are a common problem worldwide, and for design purposes it is necessary to quantify the free-swell behaviour of such material. A technique to measure the volumetric free swell of a swelling clay (called the toluene and wax-freezing volumetric free-swell method) is suggested here and consists of two approaches to measuring the volume of a specimen at different moisture contents. Both approaches have certain limitations, but fortunately they complement each other.
The author required a volumetric free-swell method which could be performed with practically zero external load on the sample during free swell and where the scatter in the recorded results would be low. An optional requirement was that one should be able to perform the test in a field laboratory with only a few samples and a minimum of equipment.
The results should be presented in such a way as to make interpretation and prediction easy.
Paper ID: GTJ10575J