The concrete flooring can be constructed either
(i) Monolithically i.e. base layer is laid and then immediately a concrete topping is provided.
(ii) Non –Monolithically i.e. the topping is laid after the base has set.
Below is the cross-section of a concrete floor
1) 4 cm concrete topping
2) 10 cm lime or lean cement concrete
3) Sand cushion
Before laying the topping, the base concrete which may be about 10cm in thickness is laid. The top surface of this base is finished roughly so as to get desired bond in between the base course and the topping. This concrete is generally of lean proportions and lime concrete is mostly used. Whenever Monolithic construction is desired, the wearing coast is placed within 45 minutes to 4 hours after placing the base. For non-monolithic construction, the surface of the base course is brushed with a striff broom and cleaned thoroughly. It is wetted the previous night and surplus water is brushed off. The floor is generally laid in rectangular panel size (2m x 2m) made with the help of battens set on mortar beds. Generally in exposed floorings (1 m x 1 m) panels are used. Then concrete is poured into these bays after a grout of cement sand mix is applied to the base course.
Concreting of alternate bays is done at one time and the intermediate bays are not laid earlier than 72 hours. For compaction of surface level we use trowelling. After that, dusting of the surface with neat cement to facilitate trowelling or the application of cement slurry to the surface should not be permitted. The floor thus laid is protected from sunlight, wind rain for at least 12 hours but preferably 24 hours. It is then kept wet by spreading a layer of wet sand for a period of at least 7 days. In the case of granolithic finish, the surface may be rubbed to get better finish. For non-slippery surfaces, can be obtained by incorporating suitable abrasives e.g. silicon carbide.
For surface hardening, three coats of sodium silicate are given each being applied after the previous has dried.