Bolted joints for UHPFRC precast prestressed elements

Author(s): E. Camacho, J.A. López, P. Serna
Paper category: Conference
Book title: 8th RILEM International Symposium on Fiber Reinforced Concrete: challenges and opportunities (BEFIB 2012)
Editor(s): Joaquim A.O. Barros
Print ISBN: 978-2-35158-132-2
e-ISBN: 978-2-35158-133-9
Publisher: RILEM Publications SARL
Pages: 1187 - 1199
Total Pages: 12
Language: English

Abstract: 
Ultra High Performance Fiber Reinforced Concrete (UHPFRC) is a material with very high compressive strength, compacity and ductility. Its properties allow conceiving it such a material between conventional concrete and steel.
To be employed for the joint between UHPFRC precast prestressed elements, a connection system based on high strength bolts, inspired on the used for steel structures is here proposed and analyzed. This process may speed the work units, increase the control, save costs and enable dismantle of the structure to be reused.
Different failure modes may be expected: The bearing, net tension, shear-out and cleavage failure of the UHPFRC, or the shear failure of the bolt. A new connection test has been developed in order to evaluate the influence of different parameters on the failure mode, the ductility and the load capacity. The lengths behind the hole and the steel reinforcement have been modified. The UHPFRC mechanical and rheological properties were characterized, and the load-displacement diagrams were obtained from the connection tests. Also, by means of an elastic analysis of the region, the cracks evolution obtained in the tests were justified.
Special attention has to be put in the casting process to reach a suitable fiber orientation that can also be reproduced in the industry. Fibers provide ductility in the area surrounding the hole, assuming an essential role. The scatter between similar elements should be studied to obtain the reliability of the fiber orientation in the casting process adopted.

Online publication: 2013
Publication Type: full_text
Public price (Euros): 0.00