Economical reinforcement of reinforced concrete structures

Abstract

Introduction. It is well known that the use of innovative types of reinforcement and advanced design methods can significantly reduce steel consumption in reinforced concrete structures. However, reinforcement consumption is also heavily influenced by the results of structural design calculations. As a rule, all reinforced concrete structure calculations are performed using computer software. The requirements of [1] aim to determine the minimum reinforcement consumption that ensures reliable structural performance. In practice, however, software often fails to comply with these code provisions. The resulting reinforcement amount may be either less or more than required. One of the main reasons for this situation is the ambiguous interpretation of codes by software developers. There are also instances of direct violations of code requirements. As a result, with identical input data, the reinforcement calculated by different software packages can differ by several times. Aim. To verify the accuracy of reinforced concrete structure calculations performed in various software packages. Materials and methods. Three test cases were examined: an experimentally verified floor slab, a foundation slab, and a slab from the “Lira-SAPR User Manual”. Reinforcement was determined using Lira-SAPR, Arbat, Lira 10, INZH-RU, Statika software packages and compared with results obtained using the “OM SNiP Zhelezobeton” computer software, which utilizes a non-linear deformation model as well as the ultimate forces method. A characteristic failure case was also analyzed. Results. The reinforcement consumption obtained from different software packages using identical input data differed significantly, in some cases by several times. Conclusions. To eliminate significant unjustified overconsumption of reinforcement, as confirmed by the provided examples, and to improve structural reliability, it is advisable to develop a document containing standard benchmark examples for reinforced concrete structure calculations. Such reference examples will help achieve consistency in results across different software packages when using identical input data. They will serve as a guideline for all software developers, structural engineers, and regulatory authorities.