ABOUT THE 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.

International Concrete Abstracts Portal

Showing 1-5 of 11 Abstracts search results

Document: 

SP183-09

Date: 

May 1, 1999

Author(s):

A. Scanlon

Publication:

Symposium Papers

Volume:

183

Abstract:

Deflection control for two-way slab systems requires attention to both design and construction requirements. This paper discusses both aspects and provides a design example to illustrate how construction loads, cracking and time-dependent effects can be accounted for in slab deflection calculations.

DOI:

10.14359/5539


Document: 

SP183-08

Date: 

May 1, 1999

Author(s):

D. Rogowsky

Publication:

Symposium Papers

Volume:

183

Abstract:

This paper deals with the selection of slab reinforcement and details from the perspective of serviceability. The focus is on extending traditional detailing rules to slabs with higher strength concrete, and to slab designs based on finite element analysis. Traditional detailing rules when used with the direct design method and equivalent frame method produce satisfactory slabs for "ordinary" applications. Slabs that fall outside the limits of applicability of the equivalent frame method are becoming more common due to the relatively ease with which one can obtain a finite element solution from elastic bending moments and forces. Detailing rules need to be gen33eralized to deal with higher strength concrete and the results of a finite element analysis, so that one can select reinforcement that provides adequate strength and serviceability. The issues addressed in this paper include: minimum reinforcement requirements; bar size, spacing and layout; bars oriented in non-principal monument directions; skew reinforcement; in-plane forces; and edge reinforcement. While there are other detailing issues, those discussed tend to have the most impact on slab performance and cost.

DOI:

10.14359/5538


Document: 

SP183-07

Date: 

May 1, 1999

Author(s):

W. Gamble

Publication:

Symposium Papers

Volume:

183

Abstract:

The Equivalent Frame Method (EFM) of the ACI Code was developed when the predominate method of structural analysis was the Moment Distribution method. It was furthermore developed primarily for vertical loadings. While there exist special-purpose programs intended for slab analysis using the EFM, the purpose of this paper is to present a method of using the EFM approach with an ordinary plane-frame program. This can be accomplished for the vertical loading case by the use of a substitute moment of inertia, Iec, for the columns. For the lateral loading case, the beam which replaces the slab in the analysis has to have a reduced moment of inertia, with the reduction having two parts. One part is to reflect the state of cracking, with the second part being an "effective width" factor which depends on the panel shape.

DOI:

10.14359/5537


Document: 

SP183-06

Date: 

May 1, 1999

Author(s):

S. Alexander

Publication:

Symposium Papers

Volume:

183

Abstract:

Hillerborg's strip method of design (1, 2) is a powerful and versatile technique for designing two-way reinforced concrete slabs and plates. The method is based on the lower bound theorem of plasticity, meaning that a design based on the strip method is always safe. The purpose of this paper is to provide an overview of the strip method, including design examples. The strip method is usually divided into tow parts. The simple strip method is used to design edge supported slabs. Many designers will recognize this as an application of the strong-band concept. The advanced strip method is used to design slabs with column supports or reentrant edge supports.

DOI:

10.14359/5536


Document: 

SP183-05

Date: 

May 1, 1999

Author(s):

S. Simmonds

Publication:

Symposium Papers

Volume:

183

Abstract:

This paper review the requirements of the upper-and-lower-bound theorems of plasticity as they apply to continuous reinforced concrete slabs. The background and assumptions leading to Johansen's yield line theory (upper-bound) and Hillerborg's strip methods (lower-bond) are presented and the advantages and disadvantages of these two methods are discussed. The segment equilibrium method proposed by Wiesinger is described and presented as an alternative procedure. It is concluded that the theory of plasticity provides a practical solution for the design of continuous reinforced concrete slabs, particularly for slab systems with irregular support geometry.

DOI:

10.14359/5535


123

Results Per Page