Shrinkage and thermal effects in R C flat plate and raft foundation

Abstract EN

In this study, the effect of shrinkage and temperature variation on thebehavior of long span reinforced concrete flat plate system and raft foundation supporteddirectly on soil or piles, has been examined via the nonlinear finite element analysis.

Inthe analysis, shrinkage has been considered as a drop of temperature of 30 oC for the flatplate system and of 20 oC for the raft foundation.

A change of temperature of uniformprofile and of nonlinear gradient have been considered.

The analysis accounted formaterial nonlinearity and it has been performed for all possible load combinations.

The results of analysis revealed that material nonlinearity plays a major role in theresponse of the structure for temperature and shrinkage effects since its presenceremarkably reduced the adverse effect of the two factors.

Shrinkage and temperaturevariation had more significant effect on slthan on rafts.

Their effect on concretestresses was not critical in sland had no significance in rafts.

On the other hand, sucheffect on steel reinforcement was noticeable in rafts and significant in slThis led tothe conclusion that the effect of both temperature variation and shrinkage can beaccommodated by additional reinforcement.

In sl, for an accurate assessment ofdeflection, it is important to account for both factors in the analysis.