트러스 모델을 이용한 순수비틀림을 받는 철근콘크리트 보의 비틀림 강도 예측

Prediction on the Torsional Strength of Reinforced Concrete Beams Subjected to Pure Torsion by Truss Model

ACI 318-99 predicts the torsional moment of reinforced concrete members by assuming that the angle of diagonal compressive concrete is equal to 45 degree. However, this angle depends on the difference of longitudinal and transverse steel ratios. This paper compares the torsional moments calculated by ACI 318-99 code and a truss model considering compatibility of strains. The comparison indicated that the torsion equation in ACI code underestimated the real torsional moment of reinforced concrete beam in which the ratio of longitudinal reinforcement was larger than that of transverse reinforcement.