00820966

Component

https://doi.org/10.3141/1770-03

http://scholar.google.com...hury&publication_year=2001

Shape memory alloys recover deformations induced at lower temperatures after being heated above a transformation temperature; restraint of this shape recovery generates relatively large stresses. These stresses are used to transfer corrective forces to structural systems for strengthening and repair. For this purpose, shape memory rods are pre-elongated, anchored to the structure, and subjected to electrical resistance heating to transfer corrective forces to the structure. The project used iron-based shape memory alloys of relatively low cost; the alloy composition was selected to yield relatively high and stable levels of restrained-shape recovery stresses. Laboratory tests verified the ability of pre-elongated rods anchored onto damaged structural systems to restore structural integrity through application of corrective forces. Subsequent damaging effects could also be overcome by electrical resistance reheating of rods. A reinforced concrete bridge structure with beams lacking sufficient shear strength at longitudinal bar cutoff locations was selected for field demonstration of the technology. A design methodology was developed and verified through laboratory tests simulating conditions of the selected bridge structure. Subsequently, a detailed design was developed and the approach was implemented under field conditions. Application of corrective (posttensioning) forces to structural systems using shape memory steel provides an efficient, rapid, and convenient approach for repair and strengthening of damaged or deficient structures. The relatively large recoverable strains of shape memory alloys help reduce losses of posttensioning forces. The approach suits application to diverse structures for corrective and strengthening effects.

This paper appears in Transportation Research Record No. 1770, Design of Structures 2001.

English

p. 20-26

2001

Transportation Research Record

0309072328

Figures (9) ; Photos (9) ; References (7)

Field tests; Laboratory tests; Posttensioning; Reinforced concrete bridges; Repairing; Stresses; Structural strengthening

Damaged structures; Deficient structures; Electrical resistance heating; Shape memory alloys

Bridges and other structures; Design; Highways; Maintenance and Preservation; I24: Design of Bridges and Retaining Walls; I61: Equipment and Maintenance Methods

TRIS, TRB, ATRI

Dec 5 2001 12:00AM

• BRIDGE SAFETY MONITORING USING COUPLED CURRENT DEVICE IMAGES
• COMPARATIVE STUDY OF AASHTO LOAD AND RESISTANCE FACTOR DESIGN DISTRIBUTION FACTORS FOR SLAB-GIRDER BRIDGES
• CONCRETE BRIDGE DECKS REINFORCED WITH FIBER-REINFORCED POLYMER BARS (WITH DISCUSSION AND CLOSURE)
• DEBRIS FLOW SIMULATION FOR HIGHWAY CROSS CULVERTS
• DESIGN OF PROFILE WALL THERMOPLASTIC PIPE FOR LOCAL BUCKLING (WITH DISCUSSION AND CLOSURE)
• DESIGN OF ROUTE 895 BRIDGE OVER JAMES RIVER IN VIRGINIA
• DIAGNOSTIC AND IN-SERVICE TESTING OF TRANSIT RAILWAY BRIDGE
• DYNAMIC LOADING OF BRIDGES
• EFFECT OF BEARING STIFFNESS AND SKEW ANGLE ON PERFORMANCE OF PRECAST CONCRETE BRIDGE
• EFFECTIVE USE OF PUBLIC INVOLVEMENT TO ACHIEVE AESTHETIC QUALITY IN BRIDGE DESIGN
• ESCAPE ADITS FOR TUNNEL SAFETY
• EXPERIMENTAL AND NUMERICAL EVALUATION OF BRACED-CHAIN EYEBAR BRIDGE
• EXPERIMENTAL CHARACTERIZATION OF METALLIC DAMPERS FOR SEISMIC RETROFIT OF HIGHWAY BRIDGES
• FATIGUE ASSESSMENT OF TRAFFIC SIGNAL MAST ARMS BASED ON FIELD TEST DATA UNDER NATURAL WIND GUSTS
• FIELD INVESTIGATION OF HIGH-PERFORMANCE CONCRETE BRIDGE DECKS IN SOUTH CAROLINA
• FIELD STUDIES OF STRENGTHENED TIMBER RAILROAD BRIDGE
• HEALTH MONITORING OF IRONTON-RUSSELL BRIDGE FOR RATING PURPOSES
• LONG-TERM DURABILITY OF STRUCTURAL COMPOSITE LUMBER IN BRIDGE APPLICATIONS
• PERFORMANCE IN LIEU OF PRESCRIPTION IN BRIDGE DESIGN: CHANGI AIRPORT MEZZANINE BRIDGE, SINGAPORE
• PERFORMANCE OF FIVE-SPAN STEEL BRIDGE WITH FIBER-REINFORCED POLYMER COMPOSITE DECK PANELS
• PERFORMANCE OF GLASS FIBER-REINFORCED POLYMER DECK ON STEEL GIRDER BRIDGE
• PUBLIC PARTICIPATION AND BRIDGE TYPE SELECTION
• RETROFITTING TO CORRECT UPLIFT OF CURVED GIRDER BRIDGE THROUGH FIELD TESTING AND ANALYSIS
• SOIL PRESSURE MEASURED AT VARIOUS FILL HEIGHTS ABOVE DEEPLY BURIED THERMOPLASTIC PIPE
• SUPERSTRUCTURE FLEXIBILITY AND DISINTEGRATION OF REINFORCED CONCRETE DECK SLABS: AN LRFD PERSPECTIVE
• TIME-DEPENDENT DEFLECTION OF THERMOPLASTIC PIPES UNDER DEEP BURIAL
• ULTRASONIC INSPECTION OF GLUED LAMINATED TIMBER FABRICATED WITH DEFECTS
• UPDATE ON ANALYTICAL AND EXPERIMENTAL RESEARCH ON BRIDGE RESTRAINERS
• VIRTUAL REALITY IMAGES TO AID PUBLIC INVOLVEMENT IN APPEARANCE OF ROADS AND BRIDGES