Title:
Residual crack width in RC and R/FRC ties subjected to repeated loads
Author(s):
Fantilli, A.P.; Tondolo, F.
Publication:
Symposium Paper
Volume:
343
Issue:
Appears on pages(s):
254-261
Keywords:
Durability, non-contact measure, reinforcement percentage, cyclic loading. 254 fib Bulletin 95: Seismic and Special Loading Conditions https://
DOI:
Date:
10/1/2020
Abstract:
Durability of reinforced concrete (RC) structure is mostly related to the ability of concrete
cover to protect the embedded rebar from corrosion initiation and propagation. As cracks due
to loads or rheological phenomena are almost inevitable, the geometry of crack pattern in
service is a key parameter that needs to be evaluated in plain and fiber-reinforced R/FRC
members. In fact, not only the direct ingress of aggressive agents, such as oxygen and water, is
a function of crack width, but also concrete carbonation and the chloride ion ingress are
accelerated by the presence of wide cracks. Furthermore, the use of fiber reinforced concrete
requires detailed investigations, in order to define the relationship between durability and crack
width even in presence of cyclic loads. Accordingly, in this research project, crack width is
measured by using traditional mechanical strain gauges and a new device based on the optical
conoscopic holography. The latter allows the non-contact measure of crack profile, at the end
of each loading cycle, both in plain and fiber-reinforced ties subjected to sets of repeated loads.
As a result, contrarily to crack width at the peak of load, the width of residual cracks is not
always reduced by the presence of fiber, and this could affect the durability of RC and R/FRC
structures.