Ocean Mall – from challenges to innovation

Shopping mall «Ocean Mall» is the construction project with high level of complexity.

The complexity of the construction processes is determined by the following factors:

–       the construction process is carried out below the level of Lybid river with intersection of the two aquifers;

–       the construction processes under the subway line, that gives a high vibration loads.

Features of the tunnels location, technological subway chambers, frame characteristics led to the necessity of considering the rigid foundation slab as a beam without support on the ground. In turn, the hydrogeological conditions led to the necessity of concrete with high waterproofing properties usage. As a result, the rigid foundation slab of20 m3of hydraulic concrete and without expansion joints has been provided.

In accordance to the construction, the decision has been taken to develop the technical regulations for concreting of the foundation slab and to choose the concrete recipe. The recipe should conform to certain parameters and conditions of the concreting of large arrays with high density of armoring in the winter.

Under the “Megaline-Invest” Ltd. control the best technologists were invited to the recipe of self-compacting concrete creation.

As a result, we received the concrete with a low content of cement ПЦІІ-АШ-400 (В32,5)- 350kg / m3, with the main maximum heat release: hour – 56  dQ/dT  – 2,8 (watt/kg), heat of hydration Q  – 198 (kJ/kg, hour 72).

Compressive strength:

1 day – 1,98
3 days – 31,05
7 days – 41,4
14 dyas – 51,45
28 days – 55,2

Tensile strength – 28 days 7,37

Ratio of tensile to compressive strength – 0,134 (for the ordinary concrete 0,1-0,11)

Frost-resistance – F 200

Watertightness – W-14

The structure of the cement stone:

Plate crystals – 20-25%

Fibrous crystals – Ø~ 16nm  – 75-80%

These features have been achieved through the complex of additives. They contribute to the formation of filiform, nano-structured crystals of cement stone Ø 10-20 nm and they have a minimum of defects in the structure with strength properties approaching the theoretical strength of defect-free crystals.