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.

Showing 1-5 of 10 Abstracts search results

Document: 

SP134

Date: 

September 1, 1992

Author(s):

Editors: Walter Gerstle and Zdenek P. Bazant / Sponsored by: Joint ACI-ASCE Committee 446

Publication:

Symposium Papers

Volume:

134

Abstract:

At the Fall meeting of the American Concrete Institute in Philadelphia in 1990, ACI Committee 446 sponsored a technical paper session entitled "Design Based on Fracture Mechanics." The purpose of the session was to present recent advances in our understanding or fracture in concrete in such a way that practitioners could understand and use it, and also to identify ways in which practitioners can make use of fracture mechanics in design of concrete structures. Currently, designers in the United States use the ACI 318 Building Code, which currently makes absolutely no use of fracture mechanics concepts. To enable designers to use fracture mechanics, a logical next step would be to incorporate these concepts into a revised building code. Note: The individual papers are also available as .pdf downloads.. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP134

DOI:

10.14359/14166


Document: 

SP134-09

Date: 

September 1, 1992

Author(s):

Christian La Borderie, Jacky Mazars, and Gilles Pijaudier-Cabot

Publication:

Symposium Papers

Volume:

134

Abstract:

Progressive microcracking and crack closure effects are the most important phenomena which need to be described in finite element calculations of reinforced concrete structures subjected to cyclic or seismic loads. Microcracking produces a loss of stiffness which is usually modeled with continuous damage mechanics. Crack closure effects such as inelastic deformations and stiffness recovery remain features that must be incorporated in the constitutive relations describing the response of concrete under cyclic loadings. These effects are introduced into a novel damage model in a rigorous, consistent fashion. An attempt to derive the constitutive relations for fiber reinforced concrete using this model is also described. The implementation of these constitutive relations into a layered beam finite element code is discussed, and computations on medium-size bending beams and a beam-column joint subjected to cyclic loading are compared with experiments. Although the computational method remains simple and sufficiently fast for engineering applications, the good agreement obtained with test data shows that the constitutive relations capture very well the main characteristics of the behavior of concrete.

DOI:

10.14359/2710


Document: 

SP134-08

Date: 

September 1, 1992

Author(s):

W. M. Ashmawi, M. H. Baluch, and a. K. Azad

Publication:

Symposium Papers

Volume:

134

Abstract:

Proposes a fracture mechanics approach to crack control design of reinforced concrete beams in flexure (Mode I). The model yields the minimum area of tension steel required of a concrete beam of rectangular cross section to safely sustain a design moment within the prescribed limit of permissible crack height. An iterative procedure is developed by satisfying simultaneously the fracture criterion of crack growth and the equilibrium condition at incipient fracture.

DOI:

10.14359/3117


Document: 

SP134-03

Date: 

September 1, 1992

Author(s):

Oral Buyukozturk and Kwang M. Lee

Publication:

Symposium Papers

Volume:

134

Abstract:

Discusses the shear design problem in concrete in the context of mixed mode crack propagation in concrete structures. Shear behavior and fracture of precast concrete segmental bridges are presented as a design case study. Joints between the precast segments of these bridges are critical locations through which large shear stresses, combined with normal stresses, must be transmitted. Crack initiation and propagation at these locations represent a mixed mode concrete fracture problem. General concepts for the representation of mixed mode fracture in concrete are briefly discussed, and a combined analytical and experimental methodology is presented for predicting this cracking behavior. Finally, using the developed fracture mechanics approach, a preliminary design concept is proposed for the shear design of prestressed concrete elements.

DOI:

10.14359/3076


Document: 

SP134-04

Date: 

September 1, 1992

Author(s):

L. Elfgren and S. E. Swartz

Publication:

Symposium Papers

Volume:

134

Abstract:

Summarizes and presents preliminary results of a round-robin analysis of anchor bolts organized by RILEM TC 90-FMA, Fracture Mechanics of Concrete-Applications. The analyses employed finite element models using fracture mechanics approaches for the most part. The assumptions used in establishing the material/cracking models varied with investigator and included linear elastic fracture mechanics (LEFM), the fictitious crack model (FCM) with linear softening or non-linear softening, a fixed crack line, a variable crack line with non-rotating cracks or rotating cracks. Crack propagation was determined using Mode I parameters, in some cases, with consideration of mixed mode behavior.

DOI:

10.14359/3081


12

Results Per Page 




Edit Module Settings to define Page Content Reviewer