Ενισχύσεις δομικών στοιχείων οπλισμένου σκυροδέματος

• Main Authors: Tsakiris, Stefanos, Τσακίρης, Στέφανος
• Format: Doctoral or Postdoctoral Thesis
• Language: Greek
• Published: Democritus University of Thrace (DUTH) 2022
• Subjects: Οπλισμένο σκυρόδεμα; Σύνθετα υλικά με ενίσχυση ινών άνθρακα; Ενίσχυση έναντι σεισμού; Reinforced concrete; CFRP; Seismic strengthening; Επιστήμη Πολιτικού Μηχανικού; Επιστήμες Μηχανικού και Τεχνολογία; Δομοστατική; Civil Engineering; Engineering and Technology; Structural Engineering; sami
• Online Access: http://hdl.handle.net/10442/hedi/52223; https://doi.org/10.12681/eadd/52223

The existence of structures designed with older codes that don’t cover new seismic requirements, makes the need for intervention to strengthen or repair them for safety reasons with advanced composites extremely urgent (Fardis et al., 2007, Bournas et al., 2009, Mirmiran et al. 1997, Rousakis et al., 2004, Sami et al., 2010). This paper deals with the experimental investigation of the behavior of reinforced concrete columns, which have been constructed according to older concrete codes and are strengthened in flexure andshear with FRP ropes and FRP sheets and the columns are subjected to combined axial and lateral pseudo-seismic load. The tests included four large scale specimens with two different cross sections 450mm x 200mm and 300mm x 300mm and height of 2000mm for both. The two columns had lap splices of the longitudinal reinforcement (540mm according to Greek Concrete Structures Code 1954) and the remaining two had no lap splices. The concrete was of quality C16/20 and the steel S500. The The tests took place in RC Lab of DUTH. After the initial testing, all the columns were repaired with mortar patch and were strengthened in flexure with NSM FRP ropes (cords). In addition, FRP unidirectional sheets provided the required shear strengthening and confinement (~30% increase). The specimens were subjected to cycles of increased lateral displacement of the free end (displacement at 1500 mm height) with a hydraulic dynamic actuator. Axial loads of the superstructure were simulated by the application of an axial fixed force of 400KN by a hydraulic actuator. LVDTs and special wire meters were used to get the measurements of the displacements at various spots (up to 350mm from the base) Η ύπαρξη πολλών κατασκευών που σχεδιάστηκαν με παλαιότερους κανονισμούς που δεν καλύπτουν τις σύγχρονες απαιτήσεις αντισεισμικότητας, καθιστά προφανή την ανάγκηεπέμβασης για ενίσχυση ή επισκευή τους για λόγους ασφαλείας με προηγμένα σύνθετα υλικά.(Fardis et al. 2007, Bournas et al. 2009, Mirmiran et al. 1997, Rousakis et al. 2004, ...