② 应用场景页
High Rise Building Steel Plate: GJC Grades and Z-Direction Performance
Columns and core walls in high rise buildings carry loads accumulated from every level above, and thick welded joints must also resist lamellar tearing. This page compares the two plate lines that answer those demands — the GJC series (Q345GJB/C/D) to GB/T 19879 and Z-direction grades Z15/Z25/Z35 to GB/T 5313 — and summarizes selection points, standard cross-references and ordering checks. All quoted values follow the applicable standards and are confirmed on the mill test certificate.
Where Loads Concentrate in a High Rise FrameColumns, core walls and transfer floors accumulate load from every level above, so wall and flange thickness grows quickly as height increases. At welded joints between column plates and diaphragms, stress acts through the plate thickness rather than along it, and that is where lamellar tearing starts. For these positions, engineers typically require building structural steel plate with guaranteed through-thickness (Z-direction) properties in addition to the base strength grade, verified by tensile and Charpy V impact tests recorded on the mill test certificate.
Suitable Grades and Selection LogicTwo product lines cover most high rise needs. The GJC series (Q345GJB/C/D) to GB/T 19879 is the base structural plate, with a yield strength of ≥345 MPa at thickness up to 16 mm, supplied in 8–100 mm thickness and 1500–3200 mm width. Where joint detailing demands it, order the same grade with a Z-direction suffix such as Q345GJCZ25, or specify separate Z15/Z25/Z35 plate to GB/T 5313. The table below aligns the two lines by standard, key property and dimensions.
Standard Cross-ReferenceGB/T 19879 covers steel plates for building structures and includes both the Q345GJB/C/D strength tiers and the Z15/Z25/Z35 through-thickness designation attached to the grade mark. GB/T 5313 is the dedicated standard for through-thickness properties, defining Z15/Z25/Z35 by reduction of area in the thickness direction. Internationally, the GJC series sits near the EN S355 building-steel tier without being an identical grade, the JIS SN series holds a similar position, and EN 10164 applies the same Z15/Z25/Z35 class system. Compare by standard number, not by grade name alone.
Practical Notes Before OrderingQualify welding procedures on the actual plate thickness, and set preheat and interpass temperatures from the approved welding procedure specification. Because impact energy and through-thickness results depend on the supply condition, confirm the delivery state, test frequency and Z-grade results on the mill test certificate for each batch, and treat any value not listed on this page as subject to the mill test certificate. For flame cutting and thick-plate joints, agree inspection points and acceptance criteria with your fabricator before production starts.
Stock, Lead Time and Next StepPer the product database snapshot of 2026-10-01, both lines are available in stock, with a minimum order quantity of 25 t and a lead time of 15–30 days, shipping from Tianjin or Qingdao, China. Send your grade (for example Q345GJCZ25 or Z35), thickness, width and quantity, and we will confirm the applicable standard, the delivery condition and the testing shown on the mill test certificate before quoting. Start through the inquiry form below.
| Grade | Standard | Key property | Thickness | Width |
|---|---|---|---|---|
| Q345GJB / Q345GJC / Q345GJD | GB/T 19879 | ReH ≥345 MPa (≤16 mm) | 8–100 mm | 1500–3200 mm |
| Z15 / Z25 / Z35 | GB/T 5313 | RA ≥15 / 25 / 35 % | 8–100 mm | 1500–3200 mm |