Evaluation of cracking potential of roller compacted concrete dam

Abstract

Concrete is a material with weak tensile strength, which makes it susceptible to cracking due to tensile stresses resulting from temperature changes that cause volume fluctuations. As a result, the problem of thermal stresses and cracks is a significant concern in the design of roller-compacted concrete (RCC) dams. RCC is a type of concrete with low cement content and low workability. It is used to support heavy equipment during transportation, placement, and compaction. RCC is typically transported using large trucks, spread using dozers, and compacted with vibratory rollers. These methods decrease the expense of constructing conventional concrete dams and have been implemented in large concrete structures because of their restricted construction period. The RCC placement rate is faster, and the placement cost is lower than that of conventional concrete, leading to cost savings of up to 50% or even 33% compared to conventional concrete. This paper discusses the thermal stress analysis of RCC dams to demonstrate the impact of temperature changes that lead to tensile stresses in the structure. The study makes use of Abaqus/CAE software and the finite element method to model and conduct transient analysis on an RCC dam. The analysis is based on the Gibe III RCC gravity dam, which is already built and stands at a height of 250 meters. The analysis considers the real-world weather conditions and thermal properties of the materials. Various modeling conditions were considered, including the use of a time-dependent or constant elastic modulus, and variation of the initial temperature from the ambient temperature. The results obtained reveal the distribution of temperature-induced stresses and the temperature in the dam body.