Prediction of characteristic compressive strength of masonry and its influence in design

Abstract

The present National Building Code published in the year 2016 has included the design newlineprovisions for promoting the construction activities of reinforced brick masonry whilst newlinecontinuing the guidelines of design of unreinforced brick masonry according to IS 1905 newline 1987. The Indian based design philosophy of unreinforced and reinforced brick newlinemasonry continues to be based on permissible stresses, assimilation of statistical newlinesignificance in latter is noteworthy and needs more attention. In design of reinforced newlineconcrete elements based on limit state designs, the ultimate stress in concrete is newlinecomputed as a function of characteristic compressive strength of concrete which is newlineregarded as an important stress block parameter. The application of a similar design newlinephilosophy to structural masonry requires more probabilistic approach and holistically newlinearriving at the characteristic compressive strength for masonry would serve as a newlinedominant factor. Also, some of the leading international masonry codes of practice such newlineas British Standards, European Standards and Australian Standards have adopted the newlinepractice of limit state designs for unreinforced and reinforced masonry encompassing newlineseveral masonry units. The design of masonry structures in compression based on limit newlinestates as practiced by western codes involves three main components - the characteristic newlinecompressive strength of masonry, stress (or capacity) reduction factors and the design newlinevertical load resistance of masonry. This research investigation primarily focuses on newlineunreinforced brick masonry by determining these three key factors with a backdrop of newlinelimit state methods and evaluates its influence in the design. The characteristic newlinecompressive strength of brick masonry has been predicted based on the significant newlineimpact of co-efficient of variation present in the data and incorporating the importance newlineof regression analysis and correlation. The design vertical load resistance of brick newlinemasonry are computed based on these results of predicted characteristic compressive newlinestrengt