Modeling crack development in reinforced concrete structures under service loading

Reinforced and partially prestressed concrete structures are generally designed to allow cracking under service loading. Accurate modeling of crack formation and propagation at lower load levels is therefore important, especially in severe environments where structural durability is a concern. Here, a spring-network approach is used to study cracking in scaled models of reinforced concrete bridge piers, which are subjected to eccentric loading. An energetic fracture mechanics approach is used to model tension softening of developing cracks. Numerical results for cracking loads, crack opening profiles, and global load-displacement response agree well with experimentally measured values. In contrast, a brittle fracture model significantly underestimates the load level of crack formation, provides unrealistic crack opening profiles at low load levels, and indicates a mechanism for structural failure different from that witnessed in the test program. (C) 1999 Elsevier Science Ltd. All rights reserved.