ANÁLISE DA FISSURAÇÃO TÉRMICA EM ESTRUTURAS DE CONCRETO MASSA ASSOCIADA ÀS PROPRIEDADES FÍSICO-QUÍMICA DO MATERIAL

Resumo

Massive concrete structures are those for which the hydration effects of the cementitious ma-
terials at the early ages, such as heat generation and autogenous shrinkage, can lead to cracking, since the

properties of the material are changing rapidly under the influence of hydration. The thermal cracking
in these structures is an important phenomenon, originated and induced mainly by matterss related to
the hydration reaction of the cementitious binder, becoming an important issue to the durability of the

structure. In this way, knowing the influence of the parameters that govern this problem is of remar-
kable importance for engineering, considering that the determination of the values of these parameters

sometimes involves complex and not exact procedures, generally obtained by inverse analysis, or simply

neglected by professionals for lack of knowledge of its impact on the project. I this work, the term mas-
sive concrete is used in a broad sense, comprising all types of concrete elements for which the effects of

cement hydration can lead to thermal cracking risks. With regard to the researches using computational
simulations, programs have been developed to map the temperature in the concrete, besides its transient
fields of tensions and deformations, enabling the prevention of cracking, through the establishment of
strategies to prevent it. In order to establish the influence of some parameters intrinsic to the material,
in this work will be simulated the construction of a concrete slab, previously builded and tested in the

laboratory of FURNAS (Goiania ˆ / GO), using the finite element program DAMTHE implemented in lan-
guage FORTRAN, developed by PEC / COPPE / UFRJ, using experimental data as the starting point for

adjustment of the thermochemical-mechanical model, aiming at obtaining a simulation of reference that
represents the most accurate tests performed and then do an factor analysis, changing intrinsic properties

of the material, such as: specific heat, activation energy, thermal conductivity and convective heat trans-
fer in order to know the influence of the correlations between the uncertainties of the input parameters of

the model in the structure cracking.