Engineering Commons^™

Evaluation Of Deterioration Of Structural Concrete Due To Chloride Intrusion And Other Damaging Mechanisms, Sudhir Palle, Brian K. Howell, Theodore Hopwood Ii, Bobby W. Meade

Kentucky Transportation Center Research Report

Kentucky's bridges continue to age and experience distress. The intrusion of chlorides into concrete remains the primary mechanism for deterioration. It leads to reinforcing steel corrosion that damages the adjoining concrete structure. This study found problematic chloride concentrations in Kentucky concrete bridge elements (decks, pier caps, abutments). Chloride levels have been found at concentrations sufficient to initiate reinforcing steel corrosion. In some cases, chloride concentrations were sufficient to cause accelerated corrosion and produce major section loss of reinforcing steel. Advanced stages of corrosion such as these typically require costly repairs and maintenance to extend the service life of bridges.

Field …

Measurement Of Transfer And Development Lengths Of 0.7 In. Strands On Pretensioned Concrete Elements, Canh Ngoc Dang

Graduate Theses and Dissertations

The implementation of 0.7 in. (17.8 mm), Grade 270 (1860), low-relaxation prestressing strands in construction is slow regardless of its advantages over the use of 0.6 in. (15.2 mm) and 0.5 in. (12.7 mm) strands. The limited research data and unavailable design guidelines partially account for the slow utilization. This study measured transfer and development length, and evaluated applicable strand spacing of 0.7 in. (17.8 mm) prestressing strands for 24 pretensioned concrete beams. Each beam contained one prestressing strand or two prestressing strands placed at spacing of 2.0 in. (51 mm). The beams were fabricated with high strength, conventional concrete …