Photogrammetric assessment of flexure induced cracking in reinforced concrete beams under service loads

Title: Photogrammetric assessment of flexure induced cracking in reinforced concrete beams under service loads
Author(s): Brad J. Pease, Mette R. Geiker, Henrik Stang, W. Jason Weiss
Paper category : conference
Book title: 2nd International RILEM Symposium on Advances in Concrete through Science and Engineering
Editor(s): J. Marchand, B. Bissonnette, R. Gagné, M. Jolin and F. Paradis
Print-ISBN: 2-35158-003-6
e-ISBN: 2351580028
Publisher: RILEM Publications SARL
Publication year: 2006
Nb references: 26
Language: English

Abstract: Reinforced concrete structures are known to crack due to restrained shrinkage, temperature gradients, application of load, and expansive reactions. Cracks provide paths for rapid ingress of moisture, chlorides, and other aggressive substances, which may affect the long-term durability of the structure. For example, concrete cracks located at the reinforcing steel may contribute to a rapid corrosion initiation and propagation. Previous research has shown that cracked reinforced concrete under static flexural loading may have an increased ingress of chloride ions along the reinforcement/concrete interface.
The aim of this paper is to provide a detailed description of the development of cracks in reinforced concrete under flexural load. Cracking at both realistic service load levels (1.0-1.8 times estimated cracking load) and unrealistically high service load levels (> 0.5 times beam capacity) has been investigated. These load levels result in relatively small cracks (<~0.1 mm) and cracks larger than expected in field concrete, respectively. The investigation constitutes a preliminary study in a project aimed at describing the effect of cracking on the transport and corrosion behaviors of reinforced concrete.
Reinforced concrete beams varying in maximum aggregate size were subjected to flexural load and the associated crack formation and propagation were monitored using three dimensional photogrammetry. The results indicate that minute cracks may cause slip and separation at the reinforcement/concrete interface. This has direct implications on the ingress and corrosion behaviors in concrete subjected to flexural loading, e.g. samples prepared for laboratory studies.

Keywords: Concrete Cracking, Three-Dimensional Photogrammetry

Online publication: 2006-08-02
Classification: 3.1 Theme 1: Numerical Models: from Microstructure to Transport Properties and Durability
Publication type : full_text
Public price (Euros): 0.00
doi: 10.1617/2351580028.041