Field Tests of Anchor Beams during Strengthening of Jiamusi Prestressed Concrete Highway Bridge

Jiamusi prestressed concrete highway bridge is located in the Jiamusi City within Heilongjiang Province in the north east of China. The application of external prestressing tendons for strengthening of existing bridges has been used in many countries since the 1950s and has been found to provide an efficient and economic solution in a wide range of the bridge types and conditions. The objectives of this study are to explain the strengthening process by using external prestressing tendons, test and analyze the anchor beams of Jiamusi prestressed concrete highway bridge. Three field tests are adopted in this study. These tests are concrete compressive strength test of anchor beams, tensile test of anchor beam re-bars, and tensile test of anchor beams structure and external prestressting tendons. The results of field tests and analysis of anchor beams and external prestressing tendons show that the value of longitudinal deformation is equal to 0.02 mm and the value of lateral strain ranges from 5 to 1 0 :g. This indicates that the anchor beams have sufficient bending stiffness and the bending capacity of anchor beam is good. The measured and theoretical values of elongation of external prestressing tendons are consistent and the values of tensile force of external tendons are less than the design tensile force (1250 kN).