Paper by SEVERI BALBO from ISCR 9th 2004 Instanbul Turkey
Results of over one year monitoring concrete pavement slabs in São Paulo, where a typical hot-wet environment prevails, were presented. The experimental test tracks comprise 15 different concrete slabs instrumented with thermal resistors allowing the monitoring of temperatures. Over the course of the monitoring, it was sought the influence of climatic conditions such as temperature and moisture on the daily and seasonal variations of temperature differentials through the slabs depths. Daytime temperature differentials of more than 15ºC were observed during typical summer days (e.g., high air temperature of 32ºC and 7.6 hours of solar radiation), and of about 10ºC during typical winter days (e.g., low air temperature of 11ºC and 3 hours of solar radiation). The absolute value of nighttime temperature differentials is not as extreme as the daytime differentials, and is significant mostly during spring and summer (September to March). Nonlinear quadratic temperature distributions through the slab thickness were evident in most cases; nevertheless, distributions that are almost linear may be present at some times during the day and even at night. The effects of tropical rains on temperature differentials are presented, and empirical models for the prediction of temperature differentials in slabs are suggested.