Open AccessExperimental Study on the Behaviours of Post-tensioned Concrete Members with Unbonded Tendons
Author(s) -
Iqbal Peera,
Nazar Oukaili
Publication year - 2021
Publication title -
iop conference series. materials science and engineering
Language(s) - English
Resource type - Journals
eISSN - 1757-899X
pISSN - 1757-8981
DOI - 10.1088/1757-899x/1067/1/012033
Subject(s) - jacking , structural engineering , prestressed concrete , compressive strength , materials science , stress (linguistics) , geotechnical engineering , ultimate load , engineering , composite material , finite element method , art , linguistics , philosophy , performance art , art history
This paper presents experimental results regarding the behaviours of eight simply supported partially prestressed concrete beams with internally unbonded tendons, focusing particularly on the effect of three different variables: concrete compressive strength, f c ′; jacking stress, f j ; and the prestressing index, ω. Increasing the concrete compressive strength from 35 MPa to 60 MPa was seen to lead to an increase in load-carrying capacity by about 10%. The load capacity was also affected, though to a lesser extent, by the jacking stress. The failure load of partially prestressed concrete beams with internally unbonded strands was increased by about 2.5%, to 10%, when the jacking stress increased from 0.5 to 0.7 of the strand’s ultimate strength, f pu . The test results showed that the prestressing index was the most influential parameter among the examined variables. The experimental results of the stress increase in unbonded strands at failure and the ultimate load resistance of members were also compared to the analytical results of various standards and research methodologies for verification.