Welded-wire reinforcement (WWR) is widely used as the main reinforcement in bridge decks and vertical shear reinforcement in concrete bridge girders. Previous studies on concrete members reinforced with WWR have indicated that the reduced ductility of the cold-drawn wires leads to lower member ductility and rupture of shear reinforcing steel at failure. Additionally, the influence of the heat-affected zones created at the electric-resistance welds raises concerns regarding the mechanical behavior at the welded connections. To evaluate the fracture behavior of WWR meshes, an experimental program was developed involving tensile and Charpy V-notch (CVN) specimens sampled from straight bars and welded intersections. Due to size constraints, both full and subsized CVN specimens were tested, and a variety of size correction methods were trialed for degree of accuracy in comparing the two sizes of specimens tested. Tensile tests showed that the cross-welds decreased ultimate strain by an average of 10% without significantly altering yield stress, ultimate strength, or elongation at fracture. CVN tests indicated that the cross-weld tended to increase impact toughness by up to $30\mathrm{J}$ ($22\mathrm{ft}\text{-}\mathrm{lbf}$ ) as the longitudinal and transverse bars became closer in size. Experimental values are evaluated using statistical methods and compared to specification minimums in American and European standards.

The master curve methodology is used to define the scatter and temperature dependence of ferritic steel fracture toughness in the ductile-to-brittle transition region, described by a single parameter, the reference temperature, To. The primary objectives of this study are to investigate the effect that different processes have on bias and precision of the reference temperature estimation, as well as the effect on the required dataset size. Analyses were performed through Monte Carlo simulations using a synthetic dataset consisting of 17,600 artificial single-edge bend KJc values censored by applicable specimen capacity limits. Reference temperature assessments were performed using both multi- and single-temperature analyses, and the effects of temperature selection, data validity weighting factors, and material homogeneity screening processes were evaluated. Multi-temperature analyses were based on a selected initial test temperature, with data sampled from subsequent temperatures based on provisionally calculated To values. The obtained reference temperature values are normally distributed with the average value remaining relatively constant regardless of test temperature. Standard deviations of reference temperatures were also relatively constant when evaluating data from test temperatures within ± 50°C (± 90°F) of the final calculated To, exhibiting less variability than predicted by the current specification. When sampling data are more than 50°C (90°F) below To, however, larger datasets are needed to obtain similar levels of precision. Guidance is provided for the modification of weighting factors to incorporate multiple confidence intervals into the validation procedure. Finally, recommendations are given on the assessment of an anomaly caused by all KJc data lying above the median master curve.