County of Bexar (Texas) Public Works Department Uses Con-Struct Prefabricated Bridge for Flood Control Culvert Replacement Project

Project Overview

When the County of Bexar (Texas) Public Works Department needed to replace the deteriorated Ira Lee Road box culverts over Salado Creek, they also needed to increase the flowable waterway area provided by the five box culverts. Due to the increased volume observed in recent years, a 104-foot-long, two-span bridge utilizing standard AASHTO Type IV prestressed concrete I-beams was specified. The county was approached by the award contractor with an alternative press-brake-formed steel tub girder superstructure that would not only increase the necessary waterway area beneath the bridge by 20 inches, but would also reduce the construction schedule by up to 45 days.  

 

Project Details

For the bridge superstructure, a press-brake-formed steel tub girder superstructure system called Con-Struct™ Prefabricated Bridge was chosen by the contractor for its ease of construction and short lead time (less than 8 weeks). The Con-Struct™ Prefabricated Bridge System consists of a precast concrete deck cast compositely on a galvanized press-brake-formed steel tub girder. The press-brake-formed steel tub girders were formed at Willbanks Metals in Tulsa, Oklahoma. The entire superstructure was then assembled at Tricon Precast, Ltd. in Houston, Texas. Tricon Precast provided a quality, cost-effective final product.

Con-Struct™ was designed for the required AASHTO LRFD HL-93 live load and to meet all applicable Texas Department of Transportation (TxDOT) and AASHTO design criteria. The 8-inch-thick precast concrete deck was provided with a tined final driving surface. The 52-foot span galvanized steel tub girders were 18-inches- deep, providing a total superstructure thickness of 28 inches. This shallow superstructure depth allowed for an additional 20 inches of clearance below the bottom of the girder.

Shipping  

The superstructure was transported to the construction site on standard individual truck trailers. Each 52-foot-long by 7-foot-wide unit weighed only 21 tons and required only a single 150-ton crane for erection.  


Installation

The 16 Con-Struct™ bridge units started to arrive at the job site by 7:00 a.m. All units were set in place by 2:00 p.m. the following day. Once set in place, high-strength, non-shrink cementitious grout was placed in the keyways between the bridge units to create one continuous 56’-4”-wide concrete deck. 

 

Final Product 

With the sidewalks and barriers formed and cast, over the next few weeks the bituminous approaches will be paved and the final riprap placed in all four quadrants. The County of Bexar Public Works Department was able to successfully replace the existing deteriorated box culverts and avoid costly rain delays by using innovative Con-Struct™ galvanized press-brake-formed steel bridge elements. With the use of the Con-Struct™ Prefabricated Bridge System, this project provided a new structure that is sustainable, cost-effective, aesthetically pleasing and environmentally friendly.  



    


Ira Lee Road Over Salado Creek Bridge Project Team

Owner                                                                                          
Bexar County Public Works

Todd M. Putnam, P.E., C.F.M.
Civil Engineer
Tel: 210.335.6696
Email:  tputnam@bexar.org
Website: http://www.bexar.org/1380/Public-Works-Department

Contractor
Tropical Contracting, LLC

Charlie Winters
Project Manager
Tel: 210.224.7920
Email: cwinters@tropicalcontracting.net
Website: https://www.tropicalcontracting.net/

Bridge Fabricators
Willbanks Metals 

Gabriel Castillo
General Manager
Tel: 918.836.2929
Email: gabe.castillo@willbanksmetals.com
Website: http://www.willbanksmetals.com/

Tricon Precast Limited 
Robert (Bobby) Lys, Jr., P.E. (TX)
Sales Engineer
Tel: 281.931.9832
Email: blys@triconprecast.com
Website: http://www.triconprecast.com/

Bridge Engineer
TEG Engineering, LLC

Guy C. Nelson, P.E., S.E.
Structural Engineer 
Tel: 616.261.8630
Email: gnelson@tegcivil.com
Website: http://www.tegcivil.com/