An Experimental Study on Pre-tensioned Concrete Members

Abstract

Abstract: Prestressed concrete elements are highly being used in the construction industry. For these kind of precast members, exposure to the loading starts at the fabrication processes. There might be high level of stress fields inside the element because of the prestressing. Exact values of these stresses are being assumed according to the linear homogenous design criteria. However, modeling a pre-tensioned prestressed concrete member via photoelastic experimental procedure could lead to make exact stress analysis in a pointwise manner. The analogy between the prestressing phenomena with photothermoelasticity led to make a pretensioned concrete model with using the “frozen-stress” method of photoelasticity. Two sorts of three-dimensional photoelastic models are prepared and analyzed with using the experimental techniques of three-dimensional photoelasticity and aimed to deal with the investigation of the pre-stress distribution after the fabrication process of the pre-tensioned reinforced concrete members. With considering the technical literature, insufficient information requires to make an investigation of the stress distribution at the vicinity of the free edges and bonding area of the reinforcing material of the pre-stressed structural members. Finally, obtained results show that some regions in a prestressed member have to endure high level of compressive and shear forces immediately after the release of prestress. This study mainly deals with the determination of the critical regions in a prestressed member and taking some precautions in order to keep the safe design margins