Original Article | 2010, Vol.32, No.4, pp. 391-402
Effect of aggregate type, casting, thickness and curing condition on restrained strain of mass concrete
Pongsak Choktaweekarn and Somnuk Tangtermsirikul
pp. 391 - 402
Abstract
In this paper, a three-dimensional finite element analysis is used for computing temperature and restrained strain in mass concrete. The model takes into account time, material properties, and mix proportion dependent behavior of concrete. The hydration heat and thermal properties used in the finite element analysis are obtained from our previously proposed adiabatic temperature rise model and are used as the input in the analysis. The analysis was done by varying size of mass concrete (especially thickness) and the casting method in order to explain their effect on temperature and restrained strain in mass concrete. The casting methods used in the analysis are continuous and discontinuous casting. The discontinuous casting consists of layer casting and block casting. Different types of aggregate were used in the analysis for studying the effect of thermal properties of aggregate on temperature and restrained strain in mass concrete. Different conditions of curing (insulation and normal curing) were also studied and compared. It was found from the analytical results that the maximum temperature increases with the increase of the thickness of structure. The use of layer casting is more effective for thermal cracking control of mass concrete. The insulation curing method is preferable for mass concrete. Aggregate with low coefficient of thermal expansion is beneficial to reduce the restrained strain.
