Definition:
It refers to the floor materials composed of organic cementing materials, inorganic cementing materials, fine aggregates, fillers and additives, which have fluidity after mixing with water (or lotion) or can flow and level after auxiliary scraping.
Advantage:
Cementitious self-leveling compound for floor overcome the slow construction speed, poor flatness, and various defects such as hollowing, cracking, peeling, sanding, and dusting that often occur in traditional cement base materials. They can be used for the construction of new floors, as well as for the repair and renovation of old floors that have been worn, sanded, or damaged. This is the development trend of ground leveling materials.
Standard(《JC/T 985-2017》):
Label 1
| Items | Specification | ||
| Surface layer | Cushion layer | ||
| Fluidity / mm | Initial | ≥ 130 | |
| After 20 min a | ≥ 130 | ||
| Adhesion strength / MPa | ≥ 1.5 | ≥ 1.0 | |
| Degree of dimension change / % | -0.10 ~ +0.10 | -0.15 ~ +0.15 | |
| Impact resistance | No cracking or detachment from substrate | ||
| Compressive strength(24h) / MPa | ≥ 6.0 | ||
| Flexural Strength(24h) / MPa | ≥ 2.0 | ||
| Wear resistance / mm³ | ≤ 400 | ≤ 800 b | |
| a :If the user has this requirement, the optional items shall be determined through negotiation between the supply and demand parties,
b :Agreed upon by both supply and demand parties. |
|||
Label 2
| Strength level | C16 | C20 | C25 | C30 | C35 | C40 | C50 | |
| Compressive strength(28d) / MPa ≥ | Surface layer | —— | —— | 25.0 | 30.0 | 35.0 | 40.0 | 50.0 |
| Cushion layer | 16.0 | 20.0 | 25.0 | 30.0 | 35.0 | 40.0 | —— | |
Label 3
| Strength level | F4 | F6 | F7 | F8 | F10 | |
| Flexural Strength(28d) / MPa ≥ | Surface layer | —— | 6.0 | 7.0 | 8.0 | 10.0 |
| Cushion layer | 4.0 | 6.0 | 7.0 | 8.0 | 10.0 | |
Recommend formula:
| Raw material | Grade | Dosage(kg/t) | Function | |
| Cement | P.O 42.5 | 250-350 | Provide strength | |
| Sulpho aluminate cement | 50-150 | Provide early strength
Improve expansion |
||
| Aluminate cement | 50 – 100 | |||
| Gypsum | Anhydrite | 20-30 | 30-50 | Improve expansion |
| Sand | 80 – 200 mesh | 150 – 200 | Aggregate | |
| Calcium carbonate | 200 – 400 mesh | 400-450 | Filler | |
| Cellulose ether | Celopro MT1004/MK400 | 0.6-1.2 | Improve suspensibility | |
| RDP | Vinabond N511 | 10.0-20.0 | Anti-crack
Improve adhesion strength Improve wear resistant |
|
| Superplasticizer | Ultraplast PC10 | 1.0-1.5 | Improve fluidity
Increase strength |
|
| Retarder | Tartaric acid | 0.5-1.0 | Extend setting time | |
| Defoamer | Foamsolver DF03 | 1.0-2.0 | Improve strength
Good surface |
|
Tips: The above formula is for reference only.
Please adjust the above formula after multiple experiments according to local environmental conditions before using it.
Normal problems & Solutions:
- Segregation and color difference:
- Adding too much water during mixing——Follow the reference on the package or supplier;
- The lack dosage of thickening agent——Add more Celopro MT1004 or choose higher viscosity level,such as Celopro MK6M;
- High dosage of superplasticizer in the formula so that small change of water dosage will lead to segregation——Change the type of superplasticizer;
- Choose the type of defoamer not match the formula——Choose Foamsolver DF03 from CEMOTECH.
- Pore on the surface:
- Lack of defoamer——Add more Foamsolver DF03;
- Water absorb rate of substrate is too high without other process of construction before——Follow standard construction techniques, watering and interface agents are necessary.
- Big fluidity loss:
- Wrong dosage of superplasticizer or wrong type of superplasticizier——Choose Ultraplast PC10,which type developed to reduce;
- Wrong dosage of retarder or wrong type of retarder——Try different retarder,such as tartaric acid,sodium gluconate,Sodium citrate etc;
- Too quick drying speed——Mortar will thicken while losing water.
- Crack and hollowing:
- Mortar losing water too quick——Avoid direct sunlight and block strong winds;
- Degree of dimension changes unqualified——Excessive expansion and contraction both lead to cracking and hollowing;
- Mortar is frozen——Water in the mortar will expands due to frozen.
- Lack of re-dispersible polymer powder——Add more Vinabond N515/511 can improve the adhesion strength and reduce the risk of crack.
