デクストラグループ |信頼性の高い接続

DEXTRA
リンクトイン フェイスブック ユーチューブ
DEXTRA
リンクトイン フェイスブック ユーチューブ
私のデクストラ

高温でのカプラ性能試験

インペリアル・カレッジ・ロンドンは、火災発生時にカプラーがどのように機能するかを評価するために、高温下で Dextra Bartec/Fortec および Griptec カプラーをテストしました。

テストのハイライトは次のとおりです。

  • 調査結果から、現在体系化された規則は、接合されていない鉄筋と、Bartec/Fortec または Griptec 連結器で連結された鉄筋の両方の強度と剛性特性を評価するために使用できることが示されました。
  • 400°C 未満の温度では、Bartec/Fortec および Griptec の接合部、および接合されていない鉄筋の最大引張強度と剛性は、大きな影響を受けません。
  • 500°C 未満の温度で引張試験を行った場合、Bartec/Fortec または Griptec 連結器領域の外側の鉄筋で破損が発生することが一般的でした。

    • Please read full article below:

    Dextra Bartec/Fortec and Griptec rebar couplers at elevated temperatures

    Dextra have recently collaborated with Imperial College London to investigate the performance of rebar couplers at elevated temperatures, simulating temperatures which could occur in rebar due to fire, both before and after concrete spalling.

    Standard 16mm and 20mm Bartec/Fortec and Griptec couplers were used, as well as non-spliced reinforcement and tests conducted at ambient, elevated steady state and transient elevated temperatures.

    testing machine

    schematic representation of the testing arrangement

    a) testing machine, b) schematic representation of the testing arrangement

    Codified procedures for the fire design of reinforced concrete structures typically give prescriptive recommendations for rebar/coupler cover with the aim of protecting the reinforcement from reaching temperatures above a critical value of around 500°C.

    The test results show that:

  • For both spliced and un-spliced specimens there is a gradual decrease in yield strength as temperature increases.
  • At temperatures below 400°C the ultimate tensile strength and stiffness of the spliced and un-spliced specimens is not significantly affected.
  • When tensile tested at temperatures below 500°C, failure still generally occurred in the rebar outside of the coupler region.

    • The findings also indicate that current codified rules can be used for assessing the strength and stiffness properties of both non-spliced rebar and rebar connected with Bartec/Fortec or Griptec couplers.

    However, the code assumptions regarding the ultimate strain characteristics at elevated temperatures were found to be unrealistic for hot rolled rebar, as well as rebar connected by couplers.

    Need more information about our couplers?

    Discover our coupler range

    参考文献

    Bompa, D. V., & Elghazouli, A. Y. (2019). Elevated temperature characteristics of steel reinforcement incorporating threaded mechanical couplers. Fire Safety Journal, 104, 8–21. https://doi.org/10.1016/j.firesaf.2018.12.006