United States Department of Transportation
i
Feasibility of using shape memory alloys to develop self post-tensioned concrete bridge girders.
-
2013-08-01
[PDF-977.74 KB]
Details:
-
Creators:
-
Corporate Creators:
-
Corporate Contributors:
-
Subject/TRT Terms:
-
Publication/ Report Number:
-
Resource Type:
-
Geographical Coverage:
-
Corporate Publisher:
-
Abstract:Post-tensioned (PT) structural elements are used quite often in bridges due to their ability to span long widths
economically while providing an aesthetically pleasing structure. PT systems are also preferred in bridge construction
because they greatly increase structural capacities and are fairly easy to implement effectively. Although PT systems
provide many advantages for designers and constructors, these systems have raised concerns regarding corrosion of
the PT tendons. The degree of corrosion of PT tendons is critical to the structural performance of PT systems and the
cost to replace tendons can exceed several hundred thousand dollars per tendon. Shape memory alloys (SMAs) are
a class of smart materials that have unique properties such as excellent re-centering ability, good energy dissipation
capacity, excellent fatigue resistance, and high corrosion resistance. This project investigated the feasibility of
developing self post-tensioned (SPT) bridge girders by activating the shape memory effect of SMAs using the heat of
hydration of grout. In particular, the project investigated the temperature increase due to the heat of hydration of
grout. A typical plastic cylinder was filled with grout at room temperature to monitor the temperature inside the duct
during the grout’s hydration. Three commercially available grouts were considered in the tests: Euclid, Sika Grout 300
PT, and Five Star Special Grout 400. The grouts were mixed in accordance with the manufacturer’s recommendation.
A single steel tendon was placed in the center. A thermocouple was attached at that tendon within the duct to
measure the temperature. A data acquisition system was used to collect the temperature data for 48 hours. The
variation of the temperature versus time was examined.
-
Format:
-
Funding:
-
Collection(s):
-
Main Document Checksum:
-
Download URL:
-
File Type:
