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International Concrete Abstracts Portal

Showing 1-5 of 12 Abstracts search results

Document: 

SP210-08

Date: 

April 1, 2003

Author(s):

C. Kassem, E. El-Salakawy, and B. Benmokrane

Publication:

Symposium Papers

Volume:

210

Abstract:

This paper presents the test results of 14 full-scale concrete beams. The beams were 3300 mm long with a rectangular cross-section of 200-mm width and 300-mm depth. Twelve beams were reinforced with carbon FRP composite bars and two reinforced with steel as control. Two newly developed types of CFRP bars with different surface textures were considered: the sand-coated ISOROD bars and the ribbed-deformed C-BAR. The beams were tested to failure in four-point bending over a clear span of 2750 mm. The results presented focus on the deflection behaviour of beams reinforced with CFRP bars, which have different bond, elasticity modulus, strain, and strength characteristics. The test results were compared to the predictions of some of the available models (ISIS-M03-01 design manual, ACI 440.1R-01 guidelines, and Razaqpur model). Based on the findings of the study, the validity of the design guidelines and the effectiveness of using the new CFRP bars as reinforcement for concrete beams were established.

DOI:

10.14359/12578


Document: 

SP210

Date: 

February 1, 2003

Author(s):

Editor: NJ Gardner

Publication:

Symposium Papers

Volume:

210

Abstract:

SP-210 This Symposium Publication contains papers presented during the 2002 ACI Spring Convention in Detroit, including six papers related to predicting the deflections of concrete members reinforced with fiber-reinforced polymer (FRP) reinforcement: one paper describes two field investigations, two unique laboratory investigations, a paper on estimating the errors in calculating deflections of high-performance concrete slabs, and a comparison of the ACI and EC2 deflection provisions. This volume should be read in association with Symposium Publication SP-203, Code Provisions for Deflection Control in Concrete.

DOI:

10.14359/14020


Document: 

SP210-02

Date: 

February 1, 2003

Author(s):

M. A. Polak, K. G. Blackwell, and D. T. Killen

Publication:

Symposium Papers

Volume:

210

Abstract:

The paper presents analysis of results from fourteen full-size tests on reinforced concrete members subject to different ratios of bending and in-plane loads. The tests examined the influence of bond between concrete and reinforcement on the deflections and cracking of the members. The parameters in the test program included reinforcing bar diameter, ratio of in-plane to bending loadings, reinforcement ratio and concrete cover. Two types of specimens were involved: one set with a larger number but smaller diameter bars, and one with a smaller number but larger diameter bars. Since reinforcement sized varied, the bond characteristics of these bars varied, leading to different load-deflection responses. The test results showed that different longitudinal reinforcement configurations, for the same reinforcement ratio and the same loading and boundary conditions, result in different cracking loads, post-cracking stiffness and deflections.

DOI:

10.14359/12572


Document: 

SP210-06

Date: 

February 1, 2003

Author(s):

H. A. Rasheed, H. Charkas, and H. G. Melhem

Publication:

Symposium Papers

Volume:

210

Abstract:

The use of externally bonded FRP plates has been established as an effective means to strengthen RC beams in flexure and shear. Few investigators have attempted to propose minor modifications to the current ACI empirical equation orginally developed for the effective moment of inertia of unstrengthened RC beams. In contrast, the present work develops a rational procedure for calculating the deflections of beams at any load stage. The procedure assumes a trilinear moment-curvature response characterized by section flexural crack initiation, yielding and ultimate capacity. This model incorporates some tension stiffening effects ans assumes the section to be fully cracked only upon or near steel yielding. A generalized solution is presented for the case of beams having any extent of uncracked, partially-cracked and post yielded regions. The curvature distribution is determined for each region and closed form equations are developed for the cases of 4-point bending and uniform load. Comparisons with experiments indicate the effectiveness of the procedure for properly anchored plates. Parametric studies are conducted to explore the applicability of the ACI original and modified equations for a wide range of geometric and material properties. As a result, improved ACI equations are suggested for use in practical deflection calculations.

DOI:

10.14359/12576


Document: 

SP210-11

Date: 

February 1, 2003

Author(s):

D. D. Kleinhans, A. Prota, and A. Nanni

Publication:

Symposium Papers

Volume:

210

Abstract:

Serviceability of FRP-reinforced concrete structures remains a highly relevant issue as more structures are constructed using the technology. With the recent publication of the ACI 440 doocument "Guide for the Design and Construction of Concrete Reinforced with FRP Bars," the need to examine serviceability-related issues and validate the accuracy of these design guidelines is heightened. A short-span concrete slab bridge was constructed in St. James, Missouri, using precast panels reinforced with FRP bars. The bridge was designed to meet AASHTO load and deflection requirements using the "Guide for the Design and Construction of Concrete Reinforced with FRP Bars." Carbon FRP, as tensile reinforcement, and glass FRP, as shear reinforcement, were utilized. Laboratory testing of one bridge panel that is identical to those installed in the field was conducted using a four-point loading configuration. Field testing of the bridge was also conducted to examine its behavior under service load. A loaded dump truck was placed at various locations along the bridge while deflections were measured and recorded. Similar field tests will be conducted annually fo rthe next three years in an effort to monitor the ong-term performance of the bridge. The results of the laboratory and field tests are summarized herein; a comparison between the theoretical and measured deflection values is made to illustrate the conservative nature of the prescribed design guidelines.

DOI:

10.14359/12581


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