Email Address is required Invalid Email Address
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
Learn More
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.
Staff Directory
ACI World Headquarters 38800 Country Club Dr. Farmington Hills, MI 48331-3439 USA Phone: 1.248.848.3800 Fax: 1.248.848.3701
ACI Middle East Regional Office Second Floor, Office #207 The Offices 2 Building, One Central Dubai World Trade Center Complex Dubai, UAE Phone: +971.4.516.3208 & 3209
ACI Resource Center Southern California Midwest Mid Atlantic
Feedback via Email Phone: 1.248.848.3800
ACI Global Home Middle East Region Portal Western Europe Region Portal
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.
Showing 1-5 of 15 Abstracts search results
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
SP272-13
K.N. Rahal
Four reinforced concrete T-beams were tested to study their behavior when strengthened for shear using near-surface mounted (NSM) bars. The objectives were to study the effects of the type of bars used (carbon fiber-reinforced polymer (CFRP) and conventional reinforcing steel) and the effects of the load level at which the bars are installed. It was observed that the CFRP bars bonded at zero load increased the shear capacity by up to 92%, while those bonded when the precracked beam was under load increased the capacity by 77%. For the steel bars, these values were 75% and 57%, respectively. The CFRP strengthened regions showed a slightly more favorable response than those strengthened with conventional steel bars. Strengthening provided an improved control of the diagonal crack width. In the beams with closer spacing of NSM bars, the increase in shear strength allowed the beam to fail after considerable flexural deformations.
10.14359/51664095
SP272-09
C. Soranakom and B. Mobasher
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.
10.14359/51664091
SP272-04
C.J. Burgoyne and H.Y. Leung
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.
10.14359/51664086
SP272-03
K.H. Tan and D. Kong
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.
10.14359/51664085
Results Per Page 5 10 15 20 25 50 100