Moisture Effects on the Bahaviour of PCC Pavements

Results of immersion-drying laboratory lest on pavement con-crete pieces show that tbe deformations produced by internalmoisture variations are as important as those produced bytemperature changes. Indirect measurements of internal mois-ture in actual pavements demonstrate the predominant existenceof a moisture differential between the slab surface and bottom.The resulting upward warping in the pavement slabs isdemonstrated by the changes in slab deflections and transversejoint openings, measured precisely during 3 years of monthlycampaigns conducted in the course of a research sponsored bythe Higway Administration of Chile.