Experimental Study on Combustion Behavior of U-Shaped Cables with Different Bending Forms and Angles

Cables are usually bent into a U-shape to cross obstacles during installation: this includes the upward-bending mode (UBM) and downward-bending (DBM). An experimental study was conducted investigate combustion behavior of U-shaped cables with above bending forms different angles. The ignition point set in middle temperature distribution, flame spread rate (FSR), mass loss (MLR), dimensional characteristics, etc. were measured analyzed. results showed that FSR MLR positively related angles, is highest UBM 90°, close 6.51 cm/min, which four times higher than angle 0° condition. In UBM, heat radiation convection from cable unburned region more intense “eruptive fire phenomenon” occurred process, leading sharp increase short time. However, thermal burning weakened DBM. Meanwhile, molten outer sheath (PE) would flow along cables, heating igniting addition, FSR, MLR, peak increased compared UBD approximately 1023 °C.