Table of Contents
Journal of Structures
Volume 2014 (2014), Article ID 524156, 13 pages
http://dx.doi.org/10.1155/2014/524156
Research Article

Precast Prestressed Concrete Truss-Girder for Roof Applications

1Omaha Public Power District, 444 South 16th Street Mall, Omaha, NE 68102, USA
2University of Nebraska-Lincoln, 1110 South 67th Street, Omaha, NE 68182, USA

Received 24 July 2014; Revised 4 November 2014; Accepted 19 November 2014; Published 14 December 2014

Academic Editor: Domenico Bruno

Copyright © 2014 Peter Samir and George Morcous. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

Steel trusses are the most popular system for supporting long-span roofs in commercial buildings, such as warehouses and aircraft hangars. There are several advantages of steel trusses, such as lightweight, ease of handling and erection, and geometric flexibility. However, they have some drawbacks, such as high material and maintenance cost, and low fire resistance. In this paper, a precast concrete truss is proposed as an alternative to steel trusses for spans up to 48 m (160 ft) without intermediate supports. The proposed design is easy to produce and has lower construction and maintenance costs than steel trusses. The truss consists of two segments that are formed using standard bridge girder forms with block-outs in the web which result in having diagonals and vertical members and reduces girder weight. The two segments are then connected using a wet joint and post-tensioned longitudinally to form a crowned truss. The proposed design optimizes the truss-girder member locations, cross-sections, and material use. A 9 m (30 ft) long truss specimen is constructed using self-consolidated concrete to investigate the constructability and structural capacity of the proposed design. A finite element analysis of the specimen is conducted to investigate stresses at truss diagonals, verticals, and connections. Testing results indicate the production and structural efficiency of the developed system.