An apparatus for testing the response of small specimens to controlled environmental changes

A modular apparatus is described with which small specimens can be subjected to controlled changes of compressive load, temperature and humidity while concurrent measurements of immediate and time-dependent deformations are made. The versatility of the apparatus is demonstrated by noting how (a) the type of material, (b) the geometry of the specimen, and (c) the timing and size of changes in any of the three environmental parameters can be selected for specific examinations. Pilot tests and typical results from tests on hardened cement paste are used to demonstrate the sensitivity, accuracy and reliability of the apparatus.