OFFER

Homepage OFFER PERFORMANCE technology

Technology of reinforced concrete tanks construction

EARTHWORKS

.After setting out the localization for a tank by a geodesist, we undertake land preparation for construction The first thing to be done is to take a layer of humus, which might and even should be used agriculturally within the farm by planting it on less fertile areas. The dimeter of excavation depends on kind of ground. In order to provide safety of workers at the excavation it is necessary to maintain proper slope to protect it against fall of ground. Furthermore, the diameter of excavation must be enlarged by working space necessary for free movement of people around the tank built. The depth of excavation should be respectively bigger than tank height because you must also add a layer of sand bed and concrete foundation. After levelling off the excavation bed you undertake to make sand bed. Its thickness depends in ground conditions that we encounter on the bottom of the excavation. An average one is between 10 and 20 cm. After drifting levels and setting out the middle of tank, sand is levelled and consolidated. Excavated material should be driven out but you must remember to leave certain amount of it needed later for ridging a tank. A very serious problem that you may often encounter is a high level of underground water. The most effective metod of drainage is application of wellpoints, which should be installed before commencing earthworks. However, if water does not come too intensively, sometimes common pumps may be sufficient to pump out water coming from the excavation.

POPRIME COAT OF 'LEAN CONCRETE'

.Subconcrete is intended to provide proper settlement of reinforcement and it increases life of steal used by increasing concrete lagging. It also allows to initially level off the bottom of a tank. Subconcrete may be made of concrete of lower classes such as C 8/10 (B10). Recommended subconcrete thickness is 10 cm. It may be made in situ, i.e. a ready concrete mix is supplied to the site by a concrete truck, and then it is spread onto surface and consolidated with a vibrating screed. Whereas using dry concrete consolidation is made with a thickener. Using dry concrete is recommended if we deal with unstable ground (water) because it affects hardening and drying the foundation. Moreover, the open time of work of such a mixture is much longer, which allows more thorough foundation leveling. Concrete is spread on the surface bigger than the diameter of tank bottom since it simplifies further construction works.

ZBROJENIE

.We make use of the latest programs for statistics calculation when designing tanks. We may be sure that our constructions are able to carry assumed loads. In case of uncovered tanks it will be loaded mosty with liquid inside and ground pressure (and wind pressure in case of unsunk tanks), whereas in case of covered tanks a decisive factor is operational load. Very ofert farms or companies have a limited space therefore there are no contraindications to locate a tank in the passageway. We realize that itis hard to predict what kind of machines will be used within your area in the future therefore at designing we asseme maximum loading envisaged by currently binding construction standards.

.Very ofert contractors neglect the issue of reinforcement of a bottom pad giving only one layer of reinforcement, which is a very serious mistake and in consequence may affect tank tightness.You must remember that the bottom pad is affected by loads both from the top (operational load) and from the bottom ( passive earth pressure). Application of reinforcement in two layers allows providing the bottom pad proper load capacity in all work directions. Maintaining proper reinforcement intensity should protect the tank against shrinkage cracks, which may appear during concrete bonding in case of improper reinforcement The higher concrete class, the higher possibility of appearance of such cracks. Another thing that you should pay attention to is providing proper concrete logging of reinforcement used. It should protect steel against corrosion. You may achieve that by using spacers of proper height. Adequately selected reinforcement should provide not only load capacity, but also usability, i.e. boundary diffractions and width of cracks specified in norms. Too big cracking of ceiling pad may result in faster steel corrosion, which means decline of construction loading capacity. Reinforcement used in our tanks guarantees fulfilling all requirements mentioned above. It is worth mentioning that most of ready to use designs available on the market are not compliant with construction standards.

TANKS TIGHTNESS

.One of main conditio of proper tank functioning is providing its long term tightness. .The most critical point is joint of the bottm pad with the vertical wall of a tank. To guarantee that special sealing tapes must be used. They must be characterised by flexibility , tightness, they must be waterproof, resistant to mineral and organic acids, caustic and saline solutions, and be properly resistant to natural aging. It is put on the perimetre of a tank wall at the stage of placing concrete of a bottom pad. Proper length of overlaps must be maintain in order to provide maximum tightness.

TANK FORMWORKstrong>

We have our own steel formwork for round tanks. Our formworks are characterised by quick erection, material saving, and a possibility to obtain maximum tank tightness. Due to stable construction of boarding and a system of stretchers, the inner and outer shells do not need direct joints. After taking off the formwork walls are smooth and there is no need to seal openings as in case of ohter types of formwork. The formwork we use allow building tanks every 0.25 m of inner diameter and of height of every 1.0 m. Due to formwork technology that we use, construction cycle of such a tank does not exceed 7 days.

CONCRETE

.Obtaining proper concrete parameters depends on many factors, and we may guarantee a long term durability of our constructions when we provide them. .One of basics is properly selected concrete class. Apart from durability it should also protect the facility against be water and frost . Proper consolidation of concrete mix is a very important element of concrete technology It causes removal of air accumulated during mixing process, which has a very strong influence upon concrete tightness and allows for more accurate reinforcement lagging. We may obtain that by vibrating concrete with vibrating screed and poker vibrators. A mistake that contractors often make is concrete 'overvibration', which results in fraction separation of concrete mixture , therefore Having long-term experience in this field we may guarantee that the concrete will be placed in accordance with principles of construction art.

.You cannot also forget about concrete maintenance. If unfavorable weather conditions occur (sun, strong winds) water necessary for proper binding of concrete mixture might evaporate. In order to avoid that systematic moistening the surface is necessary Thanks to using concrete supplied from renowned concrete plants we may guarantee you long term durability and tightness of an investment. We attach necessary conformity certificates of concrete quality to documentation. Due to proper concrete class and high quality of work surfaces of our pads as well as surrounding walls do not require any extra protection such as hydroinsulation.