Banca de QUALIFICAÇÃO: Nataniel Wontoon Barbosa Lima

Uma banca de QUALIFICAÇÃO de DOUTORADO foi cadastrada pelo programa.
STUDENT : Nataniel Wontoon Barbosa Lima
DATE: 05/12/2023
TIME: 14:00
LOCAL: UNIVERSIDADE DE BRASÍLIA
TITLE:

TENSILE STRENGTH OF BARS WITH U-TYPE HEAD AND CONNECTORS EMBEDDED IN REINFORCED CONCRETE ELEMENTS CONSIDERING EDGE EFFECT, GROUP EFFECT AND SUPPLEMENTARY REINFORCEMENT

 

KEY WORDS:

Reinforced concrete, headed bars, “U” type anchors, edge effect, group effect

PAGES: 158
BIG AREA: Engenharias
AREA: Engenharia Civil
SUBÁREA: Estruturas
SPECIALTY: Estruturas de Concreto
SUMMARY:

This work presents the results of 46 pullout tests on headed bars and “U” type bends used as cast-in anchors in reinforced concrete elements, which were divided into four experimental series. Series one, composed of 14 specimens, investigated the influence of edge effect and group effect on the anchors' experimental response and resistance for different embedment lengths. Two sets of 12 specimens were tested in the second and third experimental series to analyze the influence of supplementary reinforcement and concrete compressive strength on the anchors' performance, respectively. The specimens from the fourth experimental series evaluated the influence of supplementary reinforcement, edge and group effect on the performance of “U” type anchors. It is worth mentioning that the construction characteristics of the specimens from the first series were taken as a reference for those from the subsequent series. The experimental resistances were compared to estimates provided by theoretical models, presented by the ACI 318 (2019) and EN 1992-4 (2018) standards and proposed by Regan (2000) and Sharma et al. (2017), which are analyzed and discussed. The results showed that all specimens presented a cone-shaped failure surface. Among the parameters investigated, the embedment length showed the greatest influence on the anchors' ultimate tensile resistance. In turn, the group effect tended to reduce this resistance, especially for specimens without supplementary reinforcement. The supplementary reinforcement increased the anchors resistance in more than 50%, changed the failure mode, and raised the conservatism of the theoretical models analyzed. Among these, the model proposed by REGAN (2000) provided estimates that best adjusted to the experimental resistances, for specimens without supplementary reinforcement. In specimens with the influence of this reinforcement, the calculation method proposed by Sharma et al (2017) provided estimates closer to the experimental resistances.

COMMITTEE MEMBERS:
Presidente - 1847391 - MARCOS HONORATO DE OLIVEIRA
Interno - 1122599 - GUILHERME SALES SOARES DE AZEVEDO MELO
Externo à Instituição - MAURICIO DE PINA FERREIRA - UFPA
Externa à Instituição - MONICA REGINA GARCEZ - UFRGS