Introduction:

MESA-CTP Platform and Formwork System is designed and manufactured for construction of hyperparaboloidal cooling towers.

Basically, system is electromechanically powered for climbing operation and has steel faced formwork for concreting. It provides high degree of accuracy with clean concrete surface with a minimum labour cost.

Since the system has its own climbing power unit, it cancels crane requirement for climbing.

Each individual platform is mounted on the wall by two suspension shoes.

Basic climbing principle is to climb the lifting frame and suspend it to the shoes and fix it firstly and then to climb the main frame by the same way.

The shoes in the lower level and the current level will guide the frames basically.

Cooling Tower Platform-CTP:

CTP is divided into two main parts;

• Main Frame where all necessary operations

(i.e.concreting, reinforcement working, pre-working before climbing etc.) are done.

Main Frame consists of four working platforms in different levels.

These are Reinforcement Platform on top, Main Platform where the formworks exist, Climbing Platform where the climbing operation is realised, and the Lower Platform to dismantle the anchors and shoes to be used in next operation.

• Lifting Frame which helps to climb the Main Frame to the next level of construction.

Main Frames are connected to each other by connection platforms on the Reinforcement Platform levels, Main Platform levels and Lower Platform levels.

Electro-mechanical power unit is also located on this frame. This power unit includes one set of jack and rack bar for each Lifting Frame and one set of motor gear assembly given in a quantity which is enough to climb all platforms as five or six separate modules respectively.

Formwork:

Formwork used in the system allows good concrete surface and smooth construction joints to make easy the application of any kind of coating for protection.

Steel sheet having 4 mm thickness is especially produced for concreting and it gives high number of concreting cycles.

Formwork height is 1750 mm to obtain 1500mm height of concrete in one casting.

As main panels have 5500 mm width, they are completed with 100 mm fixed fillers and 300 mm adjustable fillers to compensate the net dimensions varying with different diameters of cooling towers due to hyperparaboloidal section of it.

Main panel in the outside has necessary curves for two wind ribs having a fix dimension to each other. Other two wind ribs in each side of the main panel are obtained by the adjustable fillers. Main panel in the outside has necessary curves for two wind ribs having a fix dimension to each other.

Other two wind ribs in each side of the main panel are obtained by the adjustable fillers. Inclination of formwork is provided by special props fixed on a carriage located on the Main Platforms.

Safety Limits:

Maximum fresh concrete pressure on the formwork is 55 kN/m².

Minimum concrete strength to suspend the platform system is 1.1 kN/cm² which is reached at the end of 3 days. The shoes currently carry the platform are located under two level of the elevation which will be concreted.

Maximum in-service-wind speed 75 km/h. This is the service limit of the CTP system. Maximum out-of-service wind speed 165 km/h. This is the limit for wind load which acts on the MESA CTP system.

Dimensional Limits:

Maximum deviation from the geometrical shape is ±20 mm. Maximum degree of formwork inclination is 21º C.

For rebar working, maximum retraction of formwork from the concrete is 550 mm. Minimum radius of concrete available by the formwork is 66 m.

Maximum height of formwork is 1750 mm. Minimum overlap on the formworks is 30 mm.