| At present，the inspection for effective prestressed of PC beam is in exploratory researchstage，there is not a complete reasonable analysis theory and effective testing method for theengineering application. The effective prestressed test method for PC beam is mainly confinedto indoor model test, and it has a very big disparity for the engineering application. Therefore,the studies for the effective prestress detection and evaluation technique of PC beams are ofgreat theoretical significance and application value for engineering use.This paper selects three pieces of25m fabricated PC beam as the research object, tostudy the relationship between the detected statics parameters and effective prestressed of PCbeam by the way of theoretical analysis and static test.Firstly, for the case of non-tensilestress in the concrete,longititudial tendon is gradually prestressed,then the paper carries outregression analysis between deflection, strain and prestress, and gives the range of actualstiffness and design stiffness ratio for the beam.Secondly, the paper carries out lateral loadingtest in certain conditions of prestressed grading, and test deflection and strain, to obtain thelaw between stiffness ratio and prestressed degree of PC beam, more over the paper set upformula between stiffness ratio and prestressed degree of PC beams. The test results show thatprestress chang the PC beams stiffness, according to the formula between stiffness ratio andprestressed degree,as well as the stiffness ratio range provided by the paper, the effectiveprestressed value of PC beam can be derived. Finally, the paper recommend two method fordetection effective prestressed of PC beam based on deflection testing.This paper carries out the PC beam effective prestressed test evaluation technologyresearch work,the results can be provide basis for testing precast PC beams or the new struc-tural operations before service, it can also give a references for bridge test evaluation technol-ogy in the future. |
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