Reliability-based assessment and optimization for the two-way shear design of lightweight reinforced concrete slabs using the ACI and EC2

• Published in: Case Studies in Construction Materials 2022-12, Vol.17, p.e01209, Article e01209
• Main Authors: Alkhatib, Soliman, Deifalla, A.
• Format: Article
• Language: English
• Subjects: ACI; EC2; Lightweight concrete; Reliability; Two-way shear
• ISSN: 2214-5095; 2214-5095
• DOI: 10.1016/j.cscm.2022.e01209

Recent brittle two-way shear failures have made assessing strength models a topic of interest. In addition, the economic alternatives have made lightweight reinforced concrete slabs (LWRCS) a popular choice of construction in many areas around the world. However, researchers have rarely tackled the two-way shear strength models of LWRCS using accurate structural reliability analysis methods. Most of the research investigations evaluated the performance of the two-way shear strength models for the LWRCS with respect to an experimental database using statistical measures. While it did not implement structural reliability methods, which could include the variability due to the following: (1) the governing variable’s random distribution; (2) the size of the experimental database; and (3) errors in measurements, construction, and design. Thus, this current study aims to apply structural reliability methods for the two-way shear of LWRCS. Two internationally renowned design codes were selected using an extensive experimental database. A brief outline of existing structural reliability methods is presented and compared. A selected reliability method was used to assess the reliability of the design-chosen codes. The reliability and sensitivity indices were calculated for the American and European design code provisions of two-way shear of lightweight concrete and compared with each other as well as international standard reliability. The American design code were found to be less reliable compared with the European, which might be due to not considering the flexure reinforcement ratio in the model. In addition, model accuracy is the main factor affecting reliability, however, the variability of basic parameters including concrete density, concrete strength and cross section depth have larger effect compared to flexure reinforcement ratio and loading area dimensions. Moreover, in order to achieve target reliability indices value of 3.8, 3.7, or 3.6 a reduction factor value of 0.8, 0.75, or 0.70 could be implemented. These findings could be helpful in design code developments. However, the results are limited to the selected variability of the random variables. •An extensive database of lightweight slabs tested under punching shear.•Two modern reliability methods were implemented.•Three international design codes were assessed.