Proj Overview

Project Overview

The existing 58-foot simple-span, reinforced concrete tied-through arch bridge over Big Chickies Creek in Lancaster County, Pa., was one of only four of its kind left in Pennsylvania. It was designed by local engineer Frank Shaw in 1916 and put into service in 1922.

The County of Lancaster contracted with the designer to create a replacement structure that offered a context-sensitive design reflecting the bridge’s distinctive historical features.

Precast Solution

The new bridge features precast concrete tied-through arches and a cast-in-place concrete deck. The designer replicated the original look of the concrete arches in precast concrete members with a compressive strength of 8,000 psi.

The final typical section of the bridge resulted in an out-to-out width of 34’-4” with two 1’-8” wide precast concrete arches matching the increased span length of 70 feet.

 

Project Team

Owner

County of Lancaster, Lancaster, Pa.

Precast Producer and Precast Specialty Engineer

Newcrete Products, Center Valley, Pa.

Engineer of Record

Rettew Associates Inc., Lancaster, Pa

General Contractor

Kinsley Construction Inc., York, Pa.

Key Project Attributes

  • Precast concrete’s aesthetic versatility allowed original arch design to be replicated with more strength and longer-term durability to reduce maintenance needs.
  • Design was cast to exact specifications in plant-controlled conditions.
  • Epoxy-coated rebar and modified mix design with reduced aggregate size provided high resistance to permeability and more corrosion resistance.

Project/Precast Scope

  • Precast concrete tied-through arches, consisting of a maximum height of 11’-7 ½”, a top chord of 1’8” x 2’0”, a bottom chord of 1’8” by 2’7”, with vertical and diagonal length of 1’0” x 1’1”
  • 47 tons per arch
  • 25,000 pounds of reinforcing and temporary post-tensioning strands.
  • Post-tensing strands used for lifting and transporting only; released after erection.
  • Form tolerances set to a maximum of 1/16 inch using survey and control equipment.
  • Modified concrete mix design with reduced aggregate size to ensure concrete consolidation.