混凝土早期断裂力学行为

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发布时间：2022-03-07

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Background
Research and practical experience show that the quality and lifetime of concrete structures largely
depend on the curing conditions in the concrete's early life, as inadequate curing leads to malfunction
and cracking. A major source of deleterious cracking already in the construction stage is the
occurrence of stresses in the hardening concrete due to restrained volume change related to hydration
temperatures and shrinkage phenomena. It is thus of utmost importance, especially regarding new high
performance concrete, that the proper execution conditions are maintained throughout the construction
period by avoiding the premature cracking.
Objective of project
Main goal of IPACS is to evaluate, integrate and extend the existing knowledge about early age
concrete crack prediction in engineering practice yielding the following benefits:
• Contractors and designers will have new and more reliable engineering instruments enabling them to
predict and to optimise the technical effect and cost of alternative designs and execution procedures -
all in the process of fulfilling the quality requirements set up by the owners or the community (codes).
• Reduced costs because of the present tendency to specify costly but unnecessarily rigorous crack
criteria will be avoided.
• Owners will have access to improved means of specifying and controlling desired quality
requirements regarding serviceability and service life of their structures.
• Reduced maintenance costs and increase of service lifetime.
Main tasks and investigations in IPACS and output from the project:
• Hydration and volume changes – To acquire data for the modelling of properties of a
number of currently used concrete types.
• Mechanical properties - Testing and modelling of mechanical properties.
• Behaviour of structures - Computer modelling of structural behaviour.
• Field tests - To check and improve the models of the previous tasks in full-scale tests.
• Expert System.
The Expert System synthesises the results from the project into a robust engineering tool for planning
and control of the production of concrete structures. It contains modules of varying simplicity, which
can be used in all the phases of a construction project from pre-design to maintenance
Project Partners:
See earlier page
Project Co-ordinator:
Dr Mats Emborg – Betongindustri AB (Heidelberger Zement North Europe) (SE)
Dr Hans-Erik Gram/Mr Mats Öberg – Cementa AB (Heidelberger Zement North Europe) (SE)
Disclaimer
The author/authors and producer of this report have used their best effort in preparing this report. Theses efforts
include the development, research and testing of the theories and programs to determine their effectiveness. The
author/authors and producer make no warranty of any kind, expressed or implied, with regard to these programs
or documentation contained in this report. The author/authors and publisher shall not be liable in any event for
incidental or consequential damage in connection with, or arising out of, the furnishing, performance, or use of
these programs.
Editorial/production supervision: Prof. Lennart Elfgren
Cover design: Hans Hedlund
Prepress material:
Printed and published by Luleå University of Technology,
Department of Civil and Mining Engineering,
Division of Structural Engineering
SE-971 87 Luleå,