It is well known that the pre-construction requirements for epoxy flooring are quite high, but the leveling and finishing of concrete floors is quite common and is generally divided into two types. One is carried out with bull float. This is usually done with dry mix cement and fine sand spread on a good surface, then smoothed with a bull float and finished with two or three coats of finish. The other is smoothed with a power trowel and finished with a bull float.
Both have certain drawbacks: The former involves stepping on an already flat surface during both the smoothing and the finishing process, making the already flat surface potholed. When the floor is finished, the surface is clearly uneven and the finish is unsatisfactory. The second type uses electric machinery, but the motor is not very powerful. The machine has to be used when the concrete is very soft. And the light harvesting effect is not ideal.
This is a great way to get the most out of a concrete floor. The construction method and other aspects of the method are described below:
Use power trowel or ride on trowel to construct the ground cement finish in outdoor conditions, not in rainy and windy weather.
The pouring party is aware of the confirmed weather conditions and must postpone the work in the event of weather changes. The ambient temperature for the work should ideally be above 2°c. The work can usually be carried out if protected indoors. The work can usually be carried out indoors if it is well protected.
Subgrade Concrete Requirements:
- Compacted foundations:
The foundations are treated according to design requirements, sand bedding, stones, etc., and compacted using machinery such as the vibratory plate compactor.
- Formwork setting:
The formwork should be flat and firm, designed according to the foundation design elevation (steel mould are preferred), and oiled. (the width of each poured concrete strip should be less than 6cm).
- Laying reinforcement:
For floors with reinforcement requirements, reinforcement should be installed according to the design specifications, with pads placed below the reinforcement. In the case of double reinforcement, the brackets should be firmly tied.
- Floor treatment:
For floor construction, the surface should be thoroughly cleared of foreign matter, and soak the surface of the grass-roots level with water one day before pouring concrete, sprinkle cement evenly before pouring concrete on the same day, and sweep the slurry, taking care not to accumulate water. The thickness of the thinnest part of concrete should not be less than 3-5cm.
- Pouring of concrete:
Concrete pouring is carried out in order by hopper operation and should be poured to the design elevation in one go. When pouring joints, it should be done after 2-3 days from the end of the next flooring, and ensure that the joint and the steel roller head are clean and free of foreign matter to prevent damage to the flooring soon after construction.
- Elevation of concrete pouring control level:
Dismantle at the end of concrete construction, otherwise, it will cause quick water collection at the elevation point, poor connection with wear-resistant flooring materials and easy crusting.
- It is recommended that the concrete meets the following conditions:
Strength is not less than c25; small cement to ash ratio as far as possible; the collapse of the soil concretion mixed on site should be controlled in 100- 120m; the largest stone diameter is not more than 30mm is appropriate, using medium and coarse yellow sand, prohibit the use of aerated additives and containing calcium chloride additives.
After concrete is vibrated, the level of the formwork should be checked with a leveling device and the deviated part should be adjusted in time.
- Floor level:
A heavier roller screed (which should be wider than 30cm than the formwork) can be used to repeatedly roll the foundation and level it with the power screed. When rolling, remove foreign matter from the surface of the steel formwork and ensure that the surface is free from dew. If you want to have the best leveling effect you can also use the concrete laser screed.
- Remove water secretion:
If there is excess slurry on the surface after the level of the floor is completed, excess secretion should be removed with a rubber hose.
Flooring Construction Instructions And Requirements
- Removal of floating slurry:
Evenly remove the floating slurry layer from the concrete surface by using a power trowel (bull float is preferred at the edge of the formwork) fitted with a disc.
- Disc lifting operation:
The power trowel operation should be staggered vertically and horizontally according to the concrete moisture condition.
- Power trowel leveling operation:
The operation should be staggered vertically and horizontally according to the hardening condition of the concrete.
- Surface finish operation:
The final finishing polishing of the concrete floor is done by surface finishing with concrete grinder or bull float.
- Mould unloading and shrink joint cutting:
Mould removal can be carried out on the third day after completion of the flooring. Care should be taken not to damage the edges of the flooring. Cutting of the shrinkage joints can be carried out on the third day after completion of the flooring and painting (dividing) of the dividing lines should be carried out on the 14th day after completion of the flooring.
For 5-6 hours after completion of the flooring, the surface can be maintained by applying a maintenance agent, or by water maintenance and film maintenance to prevent the intense evaporation of water on the surface and to ensure the steady growth of the strength of the flooring, the maintenance time is 7 days or more.
Concrete pouring-→ removing floating slurry-→ adding disc power trowel to extract slurry (3 times) -→ power trowel smoothing (2 times) -→ artificial repair i-→ surface finish (4 times) -→ artificial repair -→ maintenance.
- Pay close attention to the weather forecast and ensure that no water seeps or leaks from indoor working surfaces during rainy days, while construction of open surfaces is strictly prohibited.
- The general contractor shall notify the concrete pouring time and construction area on time and on time.
- Construction machinery and personnel: 3 sets of construction machinery and power trowel with 5 personnel (according to the daily schedule).
- 4-6 hours after the concrete pouring (after the initial setting period), cement flooring construction began, about 10-12 small dry weather conditions).
- After construction, attention must be paid to the protection of the floor and the management of the site, during the maintenance of the floor surface is strictly prohibited negative work.