| Summary: | 碩士 === 國立中興大學 === 土木工程學系所 === 94 === The purpose of this study is to investigate the flexural behavior of prestressed beams with high-workability concrete (HWC) under static load. A total of 18 prestressed beam specimens were made in this study: nine were prestressed normal concrete beams and the rest were prestressed HWC beams. The specimens had T-section, flange width was 400 mm (15.75 in), beam depth was 400 mm (15.75 in), flange thickness was 80 mm (3.15 in), and web width was 200 mm (7.87 in). The span length of the beams was 4200 mm (165.35 in). The parameters included concrete strength, amount of prestress, shear span to depth ratio, and spacing of transverse reinforcement. The following conclusions can be made from the results：
1. Prestressed HWC beams and prestressed NC beams have similar flexural strengths. The ACI simplified design method using an equivalent rectangular stress block can be used for the flexural strength design of prestressed HWC beams ;
2. Compare with NC prestressed beam, HWC prestressed beam have less prestress loss under the same condition.
3. Prestressed HWC beams exhibit better ductility than prestressed NC beams. An increase of concrete strength, decrease of prestress strength, increase of shear span to depth ratio, and decrease of spacing of transverse reinforcement would improve the ductility significantly;
4. The crack control ability of HWC prestressed beams is better than prestressed NC beams due to its better concrete quality.
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