# Large-Scale Experimental Static Testing on 50-Year-Old Prestressed Concrete Bridge Girders
###### Abstract
[8] carried out a structural load test on two PC box beams removed from a 27-year-old bridge with span length of 16.5 m. Although one beam had evidence of minor deterioration, the load-deflection curves of both beams had a ductile behavior and flexural strength greater than the expected values. [PERSON] [9] tested three PC beams of 21 m in length recovered from the replacement of a 30-year-old bridge deck. Different experimental sets-up were considered aimed at predicting bending and shear resistance. Shear failure was more difficult to predict due to dependency on the scatter in material properties and simplified assumptions in the modelling. [PERSON] et al. [10] investigated the effect of cracks on six pre-cracked PC beams after 20 years of exposure to a marine environment. The experimental results revealed that prestress loss was increased due to degradation, with a pre-cracking of 24% for post-tensioned beams and 30% for pre-tensioned beams. [PERSON] et al. [11] reported and commented the condition of a PC bridge demolished after a 54-year service life for insufficient vertical and horizontal clearance. The visual inspection that occurred after the demolition showed that the prestressing ducts were not fully grouted. The concrete cores revealed higher concrete strengths of 50% and more than the design values. [PERSON] et al. [12] proposed a method to measure the prestressing force based on the stress state around a small cylindrical hole drilled in the bottom flange of a prestressed girder. The results of the cracking test conducted on a 25-year-old PC girder indicate the promising innovation of the new non-destructive method. [PERSON] et al. [13] carried out a destruction experiment on two PC inverted T-beam removed from a 40-year-old bridge with a span length of 7.62 m. The tests revealed that a full composite action was achieved, even though the surface of the beams was not roughened and stirrups were provided as required by AASHTO specifications. [PERSON] and [PERSON] [14] conducted a loading test for four pieces of 16 m prestressed concrete hollow plate that were used for 20 years in a freezing-thawing region. Tests on the material strength showed that the performances can meet the requirements specified in the design. Moving from a pure bending load to third-point loading, the beams failed for concrete crushing at the top edge of the bending zone or for sharing-compression caused by the slippage of pre-stressed reinforcement. [PERSON] et al. [15] subjected two precast PC box beamsremoved from a 27-year-old bridge with a span length of 17.1 m to fatigue testing. Cycling to a strand stress range limit of 0.06 f\({}_{\text{pu}}\) recommended by ACI Committee 215, the beams retained excellent performance after 1,500,000 cycles, whereas cycling with a stress range of 0.11 f\({}_{\text{pu}}\) caused fatigue failure of strand wires after 145,000 cycles. [PERSON] et al. [16] carried out an experimental test to study the influence of tendon corrosion on the response behavior of structural elements. Artificial defects were induced by introducing a chemical solution or acid into the duct, reducing the load-bearing capacity to half the load achieved for the control beam. [PERSON] et al. [17] determined the effective prestress force in two PC beams removed from a bridge after a period of 28 years in service. The prestress loss obtained from an elastic analysis based on the average decompression load was 60 percent of the code-predicted value. [PERSON] et al. [18] carried out large-scale destructive tests on PC beams recovered from industrial buildings at an age of 70 years. [PERSON] et al. [19] conducted full-scale in-situ destructive tests of a 55-year-old reinforced concrete bridge deck slab on PC girders to calibrate models of one-way shear and punching shear resistance. [PERSON] et al. [20] performed load tests to destruct three deteriorated PC beams recovered from a 45-year-old bridge exposed to an aggressive marine environment.