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Composite Structures journal homepage: www.elsevier.com/locate/compstruct

Analysis of flexural concrete beams prestressed with basalt composite bars. Analytical-experimental approach

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Mantas Atutisa, , Shiho Kawashimab a b

Department of Marine Engineering, Klaipeda University, Bijunu Street 17, Klaipeda, LT 19225, Lithuania Department of Civil Engineering and Engineering Mechanics, Columbia University, 500 West 120th Street, New York, NY 10027, USA

A B S T R A C T

This present work describes the complex analysis of flexural concrete members prestressed with basalt fiber reinforced polymer (BFRP) bars considering consecutive phases of the loading applied. The aim of this research was to propose analytical approach for the prediction of effective prestress force that directly influence the serviceability limit state of prestressed concrete members, in particular to deflections. Proposed method considering prestress losses for deflection estimation is based on the concept of prestressed concrete laws within particular assumptions. The method is based on strain and curvature analysis, effective moment of inertia including decompression effect and early aging effects of both the concrete and BFRP. The instantaneous and time-dependent prestress losses, cross-sectional stressstrain, deflection and cracking behavior of concrete members reinforced with BFRP bars are described as an interrelated process. This complex approach allows to avoid disappearing of prestressing effect, such as camber or strain of decompression, as a base point and the principle of serviceability analysis of prestressed concrete members. Also, an experimental program was expanded with the purpose to evaluate the influence of prestress level for flexural stiffness of the real scale concrete beams prestressed with BFRP bars.

1. Introduction and background Currently, a growing industry requires to use optimized and affordable engineering materials and methods for sustainable infrastructure. Due to great compressive strength properties concrete is still very competitive among structural materials and have been successfully applied for marine engineering (cargo wharves, petroleum terminals, offshore platforms, piers, quays, jetties, dolphins, fender systems, bulkheads, floating barges and dry docks, etc.) [1–12] and civil engineering [13–18] (Fig. 1). The specifics of the environment of such an infrastructure requires of concrete to compete with high durability, quality assurance and control as well as maintenance requirements. The oceans present a unique set of environmental conditions that dominate the methods to be employed in construction of offshore structures [19]. Concrete and steel are principle materials for offshore structures. These materials must perform in a harsh environment, subject to the many corrosive and erosive actions of the sea, under dynamic cyclic and impact conditions over a wide range of waves and temperatures. Marine and subsea structures rank among the foremost applications of concrete. It was