Finite Element Simulation of Temperature and Stress Development in Mass Concrete

Massive hardening concrete elements are very prone to the early age thermal cracking which is a consequence of deformations that occur due to the cement hydration’ s induced temperature changes. If unrestrained, concrete in a structural element would expand and contract during the early-age heating and the subsequent cooling process without any stresses is being induced. In practice, concrete is nearly always restrained to some degree, either externally by adjoining structures or internally by different temperature development in the structure itself. Due to these imposed restrained conditions, the temperature change will induce stresses in concrete. If tensile stresses exceed still developing tensile strength of concrete, thermal cracks occur. For numerical analysis of thermal cracking, it is necessary to predict thermal field and corresponding stresses within concrete. A model implemented in a computer program DIANA was used to compute temperature and stress development. One of the challenges in the design of mass concrete structures is to avoid initiation of cracks regardless of concrete element size, concreting procedure, weather conditions and material properties. A finite element model was used to evaluate the effect of before mentioned parameters on mass concrete elements.