MPC Research Reports
Report Details

Title:	Load Testing of Wood-Concrete Beams Incorporating Recycled Utility Poles
Authors:	Matthew R. LeBorgne and Richard M. Gutkowski
University:	Colorado State University
Publication Date:	Apr 2008
Report #:	MPC-08-197
Project #:	MPC-276
TRID #:	01475837
Keywords:	bridge decks, bridge design, cast in place concrete, deflection, load and resistance factor design, rural areas, utility poles

Abstract

A wood-concrete composite bridge constructed of recycled utility poles is a potentially cost effective solution to repair a portion of the 108,647 rural bridges that have been deemed functionally obsolete or structurally deficient and have a span under thirty feet in length. This research project focuses on developing a design method for predicting the capacity of a composite longitudinal bridge deck section consisting of two utility poles topped with an interconnected concrete layer. The wood-concrete section is analyzed as a layered beam by using load and resistance factor design assuming the beam is fully composite. Adjustment factors are calculated to consider the additional mid-span stresses due to partially composite action. Full scale testing of the cast-in-place beams with a 29.52 ft span was performed with service and ultimate loads as high as 12.22 kips and 37.98 kips, respectively. The highest composite efficiency of the wood-concrete beams was determined to be 96.4 percent. An empirical relationship for modeling the time-dependent deflection during the critical 28-day curing period of the wood-concrete beams was developed.