6 Reinforcement Concrete Chimney Shell
6.1 General Requirements
6.1.1 To construct the shell of the reinforced concrete chimney，based on the actual situation，the motordriven（hydraulic）promoting formwork，slip-form，mobile relocating formwork or other technology may be applied.
6.1.2 When the slip-form technology is applied for the construction，not only the relevant provisions of this code，but also those of the current national standard GB 50113 Technical Code of Slip-form Engineering shall be complied with.
6.1.3 When the slip-form technology is applied for the construction，the shell thickness should not be less than 160mm.When the motor-driven（hydraulic）promoting formwork or mobile relocating formwork technology is applied for the construction，the shell thickness should not be less than 140mm.
6.1.4 When the slip-form technology is applied for the construction，the concrete shall not slump with forms removed，as well as no split.The concrete strength with formwork removed shall not be less than 0.2MPa.
6.1.5 When the motor-driven（hydraulic）promoting formwork technology is applied for the construction，the strength of load-bearing concrete shall be determined by the calculation in accordance with the loads on the platform.When it is below the calculating value，the platform must not be lifted.
6.1.6 The load-bearing forms at the flue opening，door openings and hopper platforms etc，shall not be removed until the concrete strength reaches the requirements of the current national standard GB 50204 Code for Acceptance of Construction Quality of Concrete Structures.
6.1.7 In the process of the chimney construction，the settlement monitoring point shall be established.The first settlement monitoring shall be carried out after the point is ready.The settlement monitoring shall be carried out at the height of every 50m in the process of construction.After the completion of the shell construction，the monitoring work shall be continued as per the provisions of the current national standard JGJ 8 Code for Deformation Measurement of Building and Structure.