TECHNOLOGICAL FEATURES OF INSTALLATION OF MONOLITHIC FLAT REINFORCED CONCRETE CEILINGS WITH INSERTS

Abstract

In recent years there is an obvious tendency to build residential, civil and other buildings with a monolithic reinforced concrete frame.

The most material cost element of these frames is monolithic reinforced concrete floors, which account from 60 to 70% of the total volume of reinforced concrete of the building. The slab thickness of such floor is 18...20cm, so the minimum weight of the floors is significant – 4-5 kN/m2, which exceeds approximately twice the running load on the floor.

The inserts are used at the floors placement in order to reduce their own weight: plastic are used abroad, polystyrene ones are mainly used in Ukraine.

During placement of such optimized floors there are a number of technological factors that affect the internal geometry and the quality of the floors with inserts.

An important technological aspect is the inserts fixation when placement of floors with inserts, which provides the design dimensions of shelves and internal arrises. To fix the polystyrene foam inserts on the height of the floor cross-section, it is necessary to use plastic spacer with expanded base  adjacent to the polystyrene foam inserts. The more expanded base take purchase in the polystyrene foam, the smaller base take purchase in the reinforcement.

Depending on the sequence of work on the arrangement of floors with inserts, they are performed on one-time concreting (one stage) or in two consecutive stages of concreting. First of all, it depends on the inserts size. Square inserts or a rectangular with insignificant in width of the unexpanded cross-section can be used one- stage stacking of concrete. In case of expanded sections of inserts it is necessary to use two-stage concreting.

Concreting floors of considerable size in the plan requires splitting into constraints by arranging technological concreting joints. They can be arranged according to the same principles (approaches) that are used for concreting of usual monolithic floors, taking into account their design scheme, possible volumes of concreting (sizes of clogs), etc. For monolithic flat floors with inserts it is necessary to take into account the direction and inserts placement form.

Concreting during the cold period of the year (especially at minus ambient temperatures) it is necessary to use known methods of "insulation" or heating of monolithic structures in the site conditions. One of the most technologically advanced and controlled in the arrangement of floors is the heating with electric current using.

The article describes and illustrates the consideration of the aforementioned technological factors in the arrangement of monolithic floors on the objects of Western Ukraine.