b'A913CIBC SQUAREEngineer: RJC EngineersFabricators: Canam/WaltersLocated in Toronto, Ont., the two office buildings at 81 and 141 Bay Street stand tall at 49 and 50 storeys, respectively. At 81 Bay Street, the first of the two towers constructed, RJC used A913 Gr65 to reduce tonnage in the columns and diaphragms. The design choice reduced material costs and alleviated loads on the projects cranes, further reducing construction costs. For the second tower, RJC incorporated A913 grade 65, 70 and 80, using all three grades for columns and grades 65 and 70 for the outrigger trusses.Photo Credit: RJC Engineersprovides a direct benefit to the fabricator andon Canadian projects through CSA W59-24In addition to the preheat benefits, reducing the project as a whole. AppendixP,whichpermitslowerpreheatthe size of the steel section can also dramatically At Walters, welding heavy columns fromtemperatures for steels with lower PCMs.reducethesizeofweldsonaproject.For A913material(especiallywiththeincludedThese advantages can also be utilized oninstance, if a column size is reduced by 20 per toughness&lowerresidualstresses)offersprojectsintheUnitedStatesthroughAWScent using A913 steel, the required volume for a peace of mind that the risk of cold cracking isD1.1.Inthe2020editionofthecode,A913welded splice on this column can be reduced as significantly reduced. A913 is great material toGr50andGr65areprequalifiedforweldingmuch as 45 per cent, as less passes are needed work with from cutting, drilling to welding andwith no preheat for all base metal thicknesses,to complete the weld. Multiplying these savings galvanizing says Yasser Elmasri (Director ofprovidedthattheambienttemperatureisin weld volume and preheat across a full project Quality AssuranceWalters Group). above0C(32F)andanelectrodewithatranslates to a significant reduction in schedule Toaccuratelycapturethesebenefits,diffusible hydrogen content of 8ml/100g (H8) isand cost for the fabricator and project team.CSAW59-24usesaformulatocalculateaused. If the ambient temperature drops below CompositionParameter(PCM),which0C (32F) a preheat of 20C (70F) is permitted.Reducing Embodied Carbonprovides a weighted average of the alloys thatUpon the release of AWS D1.1 2025, similarThebenefitsofreducingsteeltonnageina negativelyimpactwelding.SincetheA913provisions will allow for prequalified welding atbuilding go further than cost savings. By using specification puts tighter limits on carbon andreduced preheats for A913 Gr70 and Gr80 asless material, there is also a dramatic reduction in other alloying elements the PCM values forwell. The chart below shows the prequalifiedembodied carbon. Further, due to the efficiency A913 steel are typically much lower than similarpreheating temperatures for all A913 grades asof the QST process, there is no embodied carbon A992sections.Thisbenefitcanberealizeddefined by AWS D1.1 2025.difference between A992 and A913 steel, which Minimum Preheat Temperatures C [F] (prequalified)Thickness, mm [in.] A992 & A572A913Grade 50 Grade 50 & 65* Grade 70 Grade 803 to 20 [1/8 to 3/4] 0 [32] 0 [32] 0 [32] 0 [32]20 to 38 [3/4 to 1-1/2] 10 [50] 0 [32] 0 [32] 10 [50]38 to 65 [1-1/2 to65 [150] 0 [32] 0 [32] 65 [150]2-1/2]Over 65 [2-1/2] 110 [225] 0 [32] 65 [150] 110 [225]*Requires low hydrogen diffusible electrode, H8, or better.**Requires low hydrogen diffusible electrode, H4, or better.For metal at temperatures below 0C (32F), minimum preheat is 20C (70F).26|SPRING 2025 ADVANTAGE STEEL'