Strength evaluation of early-age full-scale unreinforced masonry walls against out-of-plane loading using experimental and numerical studies

There is a lack of understanding of the early-age (within the first seven days) strength properties of masonry. As a result, the design of temporary wind bracing of masonry during construction tends to error on the side of excess conservatism and consequently ends up being more costly and complex than what may otherwise be required. The consequences of failure of these bracing systems are catastrophic, yet there is a lack of research and definitive design guidance available for engineers who may seek to better optimize their design. This paper investigates the strength and behavior of early-age full-scale masonry walls subjected to out-of-plane loading through comprehensive experimental and numerical studies, aiming to fill the gaps in current masonry design codes and facilitate robust, accurate and cost-effective wind bracing of masonry during construction. Recognizing the vulnerability of early-age masonry to wind-induced out-of-plane forces, an innovative test setup was developed to evaluate cantilever and simply-supported masonry walls. A total of 60 full-scale walls were tested at various stages of curing prior to full 28-day strength. A novel setup, validated by different types of recorded data and digital image correlation analysis, was designed to capture the walls' behavior. Key findings indicate that the early-age walls showed minimal tensile strength until 24 hours and achieved ∼50 % and ∼73 % of their full strength within the first 24 and 72 hours, respectively. The relationships between tensile strength and curing time were found to be logarithmic. Regression models were developed for predictive purposes. Also, there is no meaningful difference between the tensile strength of simply supported walls and cantilever walls. The tensile strength of early-age walls was found to be significantly higher than that of axial tensile strength of masonry prisms and mortar cubes, especially during early ages when primary hydration had not fully occurred. Masonry that has reached its 28-day strength showed good agreement with specified flexural tensile strength in design codes, confirming the reliability of the test setup and the experimental results. A finite element model was employed to simulate the walls, showing good agreement with experimental results. The proposed predictive regression model also estimated properties for curing times not covered experimentally, providing insights for designing temporary bracing systems for early-age masonry, and highlighting the potential for improved safety and efficiency in construction practices. • This paper evaluates the early-age strength of full-scale masonry walls by conducting extensive numerical and experimental studies. • Early-age masonry walls reach ∼50 % of lateral strength at 24 hrs and ∼73 % at 72 hrs, with a logarithmic increase. • There is no significant difference in flexural tensile strength between early-age cantilever and simply supported walls. • The finite element model accurately predicts lateral strength and failure modes of early-age walls. • Findings suggest potential revisions to CSA-S304 for shear resistance and flexural tensile strength of cantilever walls. • Flexural tensile strength of masonry walls exceeds axial masonry assemblage tensile strength by 3.6 times and mortar cube tensile strength by 1.46 times, more notably at t < 24.

Récupéré en direct depuis OpenAlex et désinversé. Les résumés ne sont pas conservés dans cette base de données : les index inversés représentent 8,6 Go des 9,3 Go de texte de la base, et le serveur dispose de 13 Go libres.