International Concrete Abstracts Portal

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 15 Abstracts search results

Document: 

SP272-09

Date: 

October 1, 2010

Author(s):

C. Soranakom and B. Mobasher

Publication:

Symposium Papers

Volume:

272

Abstract:

Parameterized material models for strain softening fiber-reinforced concrete are used to express closed-form solutions of moment-curvature response of rectangular cross sections. By utilizing crack localization rules, one can predict flexural response of a beam. A parametric study of post crack tensile strength in the strain softening model is conducted to demonstrate general behavior of deflection softening and deflection hardening materials. Uniaxial and flexural test results of several polymeric fiber-reinforced concrete mixtures are used to demonstrate the applicability of the algorithm to predict load-deflection responses. The data are compared with the ASTM International test Method C1599, which represents the residual strength of the sample after cracking has taken place. The simulations reveal that uniaxial tensile stress-strain relationship is under-predicted using the flexural response test results.

DOI:

10.14359/51664091


Document: 

SP272-06

Date: 

October 1, 2010

Author(s):

S.P. Shah, L. Ferrara, and S.H. Kwon

Publication:

Symposium Papers

Volume:

272

Abstract:

The synergy between self-consolidating concrete (SCC) and steel fiber-reinforced concrete (SFRC) technologies may yield, besides the well known and assessed characteristics of each single technology, several interesting peculiar advantages that can be fruitfully exploited by the construction industry, mainly in the field of precast construction. Better controlled fiber dispersion, improved fiber-matrix bond, and enhanced durability due to the higher compactness of the SCC matrix are among the most relevant issues to which the largest part of research efforts were dedicated in the very last decade. The robustness of self-consolidating steel fiber-reinforced concrete (SCSFRC), which relies on sound mix-design methodology and on effective dedicated quality control procedures, has been demonstrated to be crucial in order to achieve the above recalled advantages. This paper summarizes the most significant results of the research activity carried out by the authors in this field, furthermore underlying the outcomes with reference to structural applications.

DOI:

10.14359/51664088


Document: 

SP272-07

Date: 

October 1, 2010

Author(s):

D. Joo Kim, S. El-Tawil, and A.E. Naaman

Publication:

Symposium Papers

Volume:

272

Abstract:

The effect of matrix strength (or composition) on the pullout behavior of high strength deformed steel fibers is investigated. High-strength steel hooked (H-) and twisted (T-) fiber are used in three different matrices with three different compositions generating a low (4.1 ksi [28 MPa]), medium (8.1 ksi [56 MPa]) and high (12.2 ksi [84 MPa]) compressive strength. Although both fibers produce a higher pullout load with a higher compressive strength matrix, T- fiber shows a more sensitive behavior to the matrix strength or composition than H- fiber. Moreover, T- fiber leads to significant enhancements in both pullout load and pullout energy in higher strength matrix than in lower strength matrix. It is observed that T- fiber is generally more efficient in a higher-strength matrix than in a lower-strength matrix.

DOI:

10.14359/51664089


Document: 

SP272-03

Date: 

October 1, 2010

Author(s):

K.H. Tan and D. Kong

Publication:

Symposium Papers

Volume:

272

Abstract:

This paper presents a simple direct method to determine the external tendon configuration required for a desired increase in load-carrying capacity of continuous beams. The tendon layout is selected based on the concept of equivalent loads, but need not be concordant. By considering the collapse mechanism of the beam, the increase in load-carrying capacity can be related directly to the tendon force. It is shown that the increase in load-carrying capacity is partly due to an increase in the force in the compression zone arising from the horizontal component of the prestressing force, and partly due to the upward components of the prestressing force. The method was verified with a test program on six two-span continuous beams, in which the tendon profile and loading pattern were varied. Comparison of the test results and those available in the literature showed that the proposed method gives a reasonably conservative design. A simplified method based on the direct balancing of increased loads is also proposed.

DOI:

10.14359/51664085


Document: 

SP272-04

Date: 

October 1, 2010

Author(s):

C.J. Burgoyne and H.Y. Leung

Publication:

Symposium Papers

Volume:

272

Abstract:

This paper describes an experimental study of a new form of prestressed concrete beam. Aramid Fiber Reinforced Polymers (AFRPs) are used to provide compression confinement in the form of interlocking circular spirals, while external tendons are made from parallel-lay aramid ropes. The response shows that the confinement of the compression flange significantly increases the ductility of the beam, allowing much better utilization of the fiber strength. The failure of the beam is characterized by rupture of spiral confinement reinforcement.

DOI:

10.14359/51664086


123

Results Per Page 




Edit Module Settings to define Page Content Reviewer