Abstract：
Experimental study on the prestress losses of transversely prestressed concrete beams when using high strength bolts of grade 10.9 as transverse prestressing bars was carried out, and the following conclusions can be drawn: （1） the prestress losses caused by pipe friction reached 3%~5% of the tension control stress; the prestress losses caused by the deformation of steel pad, the bolt shrinkage and the compression of the joint reached 1%~3% of the tension control stress; and the prestress losses caused by elastic compression of concrete reached 1%~3% of the tension control stress; otherwise the long-term prestress losses reached 12% of the tension control stress. （2） the FEM analysis result shows that the influence scope of each tensioned high strength bolt is 900 mm. （3） the formulas to compute the prestress losses when using high strength bolts of grade 10.9 as transverse prestressing bars were suggested.
