Adjustable Restraining Frames for Systematic Investigation of Cracking Risk and Crack Formation in Reinforced Concrete Under Restrained Conditions

Dirk Schlicke*, Katrin Hofer, Viet Tue Nguyen

*Corresponding author for this work

Research output: Chapter in Book/Report/Conference proceedingChapter

Abstract

The Institute of Structural Concrete at Graz University of Technology developed adjustable restraining frames (ARFs) in order to enable systematic investigations of the behaviour of reinforced concrete under restrained conditions. The focus was hereby set on the following aspects:holistic experimental simulation of the stress history due to imposed deformations including cracking and crack opening by time, as well asexperimental determination of cracking patterns to be expected in externally restrained and ordinarily reinforced thick members (reinforcement is located near the surface whereby the core is not affected by reinforcement; A c ≫ A c,eff). The results of these experiments give profound insights on the stress history, the cracking risk, the crack pattern and further crack opening to be expected due to the complex interplay of thermal, hygric and mechanical behaviour of concrete. Special attention was given to the restraining condition as well as the present reinforcement. In particular, the most important results of the whole campaign were:confirmation and additional findings regarding the effect of viscoelastic behaviour on the hardening-induced stress history,clarification of the behaviour of reinforced concrete when it comes to superimposition of hardening-induced stresses with further stresses due to imposed deformations during service life andexperimental verification of the existence and effectiveness of secondary cracks in thick members on the limitation of the crack width of the primary crack. Besides the outlined findings and their application in guidelines for crack risk assessment (ÖBV in Analytical design of watertight structures with optimized concrete (in German). Austrian society for construction technology, Vienna, Austria, 2018) as well as crack width control and jointless design (BAW in Merkblatt früher Zwang – Rissbreitenbegrenzung für frühen Zwang in massiven Wasserbauwerken. Referat Massivbau der BAW, Karlsruhe, 2010; BAW in Merkblatt Zwang bei fugenlosen Wasserbauwerken. Referat Massivbau der BAW, Karlsruhe, 2019), these experiments provide also clear and transparent data for the verification of thermo-mechanical calculation models for simulation of hardening-induced stress histories, (e.g. Schlicke in Mindestbewehrung für zwangbeanspruchten Beton. Graz University of Technology, Graz, 2014; Heinrich in effiziente Berechnung viskoelastischer Spannungen in gezwängten Bauteilen. Graz University of Technology, Graz, 2018; Jędrzejewska in Constr Build Mater 174, 2018) as well as nonlinear calculation models for simulation of secondary cracking in thick concrete members.

Original languageEnglish
Title of host publicationAdvanced Techniques for Testing of Cement-Based Materials
PublisherSpringer Nature
Chapter7
Pages211-239
Number of pages29
ISBN (Print)978-3-030-39737-1
DOIs
Publication statusPublished - 2020

Publication series

NameSpringer Tracts in Civil Engineering
ISSN (Print)2366-259X
ISSN (Electronic)2366-2603

Keywords

  • Crack width development
  • Cracking risk
  • Restraining frames
  • Restraint stressing
  • Superposition of hardening-induced stresses with restraint stressing during service life

ASJC Scopus subject areas

  • Civil and Structural Engineering

Fields of Expertise

  • Sustainable Systems

Fingerprint Dive into the research topics of 'Adjustable Restraining Frames for Systematic Investigation of Cracking Risk and Crack Formation in Reinforced Concrete Under Restrained Conditions'. Together they form a unique fingerprint.

Cite this