In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Become an ACI Member
Founded in 1904 and headquartered in Farmington Hills, Michigan, USA, the American Concrete Institute is a leading authority and resource worldwide for the development, dissemination, and adoption of its consensus-based standards, technical resources, educational programs, and proven expertise for individuals and organizations involved in concrete design, construction, and materials, who share a commitment to pursuing the best use of concrete.
American Concrete Institute
38800 Country Club Dr.
Farmington Hills, MI
Chat with Us Online Now
Feedback via Email
Home > Publications > International Concrete Abstracts Portal
The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.
Title: Some results of experimental researches on bond in reinforced concrete members
Author(s): J. J. Pędziwiatr, L.J. Jankowski
Appears on pages(s): 37-55
Keywords: bond,reinforced concrete
Abstract:Intensive studies and experimental researches on bond, which have been carried from early 70, have not lead to significant results. In engineering practices and national codes, still exist recommendations based on researches from early 70 or even older. The main source of that situation is fact that most experiments were conducted on RILEM recommended specimens with a very short embedded length and under axial tension. Such researches are relatively cheap and easy to carry but their results cannot be used in concrete structures analysis. Too short development length leads to unrealistic values of both slips and bond stresses caused by effect of strain concentration and a slip of free bar end. At the other hand, their length cannot allow to create internal cracks, which play very important role in forces transfer from a bar to surrounding concrete. Our own researches were carried mainly on eccentric tension members that have length, which allow arising of several cracks. A shape of cross-section and such arrangement of bars position that they were faced with a specimen edge, make possibility to direct measurement of steel and concrete strains. Elastooptical surfaces glued to different parts of specimens allow observing changes in strains distribution on large areas and discovering some phenomenon, which can hardly be seen using classical methods. Thanks to researches, it was possible to explain some problems of crack creation and development and of forces transfer from a bar to concrete. It was confirmed that internal cracks play an important role in states of deformation and cracking for members under axial and eccentric tension, which are reinforced with deformed bars. Researches allow reliable explanation sources of such phenomenon as a very large variation of crack width and spacing values. Also non uniform concrete strain distribution in perpendicular cross-section in axially tensioned member, can be explain. Researches confirmed theoretical model presented earlier very well and allow extending and improving it.
Polish Academy of Sciences, International Partner Access.
View Resource »
Web View »
USE YOUR REPAIR SUBSCRIPTION