Cable shaft blockingEffectiveness in stopping the spread of fire

　　High-rise buildings, lift shafts, pipe wells, cable shafts and other vertical shafts, if the fire separation is not handled well, in the event of a fire, these shafts are like a small chimney, becoming a way for the rapid spread of fire, for the cable shaft, especially the cable shaft of the communication building, from the actual need for the cable shaft. Especially the cable shaft of the communication building, taking into account the cable maintenance, replacement, laying, but also to ensure fire safety, cable shaft can be used plasticity organic fire plugging and quick-setting inorganic fire plugging fire blocking separation, plasticity organic fire plugging has a very high fire resistance, good flexibility, and some have the characteristics of the fire expansion and so on. It is very convenient for cable construction and maintenance. So it is especially suitable for buildings in the wires, cables and pipes through the holes, gaps in the fire blocking, quick-setting inorganic fire plugging material when used, generally first wrapped in the periphery of the cable with organic fire plugging material. In the periphery of the gap at the filling of fast-fixing fire plugging material, fast-fixing fire plugging Section curing, the formation of fireproof layer with considerable strength and fire resistance.

　　Cable shaft blockingmethodologies

　 (一) with cement filling method. At present, many of the old neighborhood cable wells are not set up bridge, directly around the cable with cement for filling and sealing. Although there is a certain role in fire prevention, but not conducive to the maintenance of the cable later.

　　(二) fire clay blocking method. Fire clay plugging method fire clay plugging material for fire and smoke have a better blocking effect, but also easy to dismantle and replace. But the fireproof mud is generally softer, in the blocking area of a smaller space is more suitable. In addition, there are fire clay will appear in the heat dripping phenomenon, and in the cold season when the viscosity is easy to fall off and lose or reduce the effect of blocking.

　　(三) fireproof package blocking method. Fireproof package fire resistance performance is superior, easy to block and dismantle. Firestopping package in case of fire when the package blocking material rapidly expanding and blocking the flue, can effectively block the flame and smoke. Shortcomings: First, the bridge blocking construction difficulties. A slip. Second, the early stage of the fire Yin combustion stage blocking can not be toxic gas flow, so that the application of the firestopping package is greatly restricted. Third, the quality of the firestopping package is uneven, many firestopping packages are not produced according to standards, poor firestopping performance.

　　(四) fireproof cotton blocking method. Through many tests and consider the construction difficulty and cost factors, with fireproof cotton blocking cable wells have low cost, good fire and smoke performance, long shelf life, construction convenience and ease of cable maintenance advantages, blocking method: first open the bridge, the large piece of fireproof cotton stuffed into the bridge in the floor at the cable larger gaps, and then a small piece of fireproof cotton stuffed into the smaller gaps, fireproof cotton should be plugged tightly plugged to ensure that no air circulation up and down in the bridge, the thickness is not less than the thickness of the bridge. Air circulation, the thickness is not less than the thickness of the floor, the holes outside the bridge less than 300cm ² can also be directly sealed with fireproof cotton, holes larger than 300cm ² need to be first depending on the circumstances of the erection of reinforcing steel and pouring cement, to ensure that the load-bearing capacity.