International Concrete Abstracts Portal

Showing 1-5 of 877 Abstracts search results

Document: 

23-117

Date: 

May 1, 2025

Author(s):

Mustafa M. Raheem and Hayder A. Rasheed

Publication:

Structural Journal

Volume:

122

Issue:

3

Abstract:

Extensive experimental verification has shown that the use of fiber-reinforced polymer (FRP) anchors in combination with externally bonded FRP composites increases the flexural capacity of existing reinforced concrete (RC) structures. Thus, a rational prediction model is introduced in this study so that fiber splay anchors may be accurately designed for practical strengthening applications. Simplified structural mechanics principles are used to build this model for capacity prediction of a group of fiber splay anchors used for FRP flexural strengthening. Three existing test series using fiber splay anchors to secure FRP-strengthened T-beams, block-scale, and one-way slabs were used to calibrate and verify the accuracy and applicability of the present model. The present model is shown to yield very accurate predictions when compared to the results of the block-scale specimen and eight different one-way slabs. The proposed model is also compared with the predictions of a design equation adapted from the case of channel shear connectors in composite concrete-steel construction. Results show a very promising correlation.

DOI:

10.14359/51745639


Document: 

23-107

Date: 

March 25, 2025

Author(s):

Graeme J. Milligan, Maria Anna Polak, and Cory Zurell

Publication:

Structural Journal

DOI:

10.14359/51746718


Document: 

22-392

Date: 

March 1, 2025

Author(s):

Jong-Hoon Kwon, Bum-Sik Lee, Sung-Hyun Kim, and Hong-Gun Park

Publication:

Structural Journal

Volume:

122

Issue:

2

Abstract:

The present study investigated the contribution of slabs to the lateral load-carrying capacity of shear walls coupled with slabs. Cyclic lateral load tests were conducted on five two-story wall specimens at half scale. The test parameters included the thickness of the slab, the wall opening length, the use of punching shear reinforcement, and the use of parallel walls. The test results showed that, due to the slab effect, the strengths of the coupled wall specimens were 38 to 88% greater than the strength of walls without the slab effect. Furthermore, the initial stiffness of the specimens was significantly increased by the slab effect. During early loading, local failure of the slabs occurred at the wall-slab connection. However, the coupled walls exhibited ductile behavior up to a 2% drift ratio, without significant degradation of strength. Nonlinear finite element analysis was performed on the test specimens. Based on the results, the initial stiffness and effective stiffness of the walls and coupling slabs were evaluated for the seismic design of coupled walls.

DOI:

10.14359/51743301


Document: 

23-095

Date: 

March 1, 2025

Author(s):

Graeme J. Milligan, Maria Anna Polak, and Cory Zurell

Publication:

Structural Journal

Volume:

122

Issue:

2

Abstract:

Worldwide punching shear design provisions for interior slab-column connections subjected to concentric shear differ greatly in how to account for column rectangularity (aspect ratio). In some, a reduced nominal shear capacity along the critical perimeter is assumed, whereas an effective or reduced critical perimeter is assumed in others. In this paper, three alternative methods to estimate the concentric punching shear capacity of interior rectangular slab-column connections without shear reinforcement, which implicitly account for the influence of column rectangularity and the ratio of the minimum column dimension to the effective slab depth, are presented. The accuracy of the proposed methods is studied through comparisons to 76 nonlinear finite element models and 86 experiments. The predicted punching capacities from the proposed methods and ACI 318-19 are also compared.

DOI:

10.14359/51739194


Document: 

24-030

Date: 

February 11, 2025

Author(s):

Kwanwoo Yi and Thomas H.-K. Kang

Publication:

Structural Journal

Abstract:

This study examined how tendon configuration affects the temperature behavior of post-tensioned concrete structures during fire exposure using finite element analysis. The thermal behavior of various tendon configurations was modeled, showing good agreement with experimental data. Parametric studies found that unbonded single-strand tendon (S) and prestressing (pre-tensioned) strand (R) had lower thermal resistance compared to bonded post-tensioned tendon (B), unbonded post-tensioned tendon (U), and grouted extruded-strand tendon (G). The S and R specimens stayed at or below the critical temperature for one-way slabs, validating current safety codes. The B, U, and G specimens remained well below critical temperatures, indicating thinner concrete cover might suffice. These findings highlight the need to consider tendon configuration in structural fire resistance evaluation and incorporate heat resistance assessment to ensure the safety and efficiency of prestressed concrete structures during fires.

DOI:

10.14359/51745642


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