Concrete expanding admixture is a kind of additive that produces controllable expansion of concrete (including mortar and cement slurry) to reduce shrinkage during cement setting and hardening process. It depends on its own chemical reaction or reaction with other components of cement, in the initial stage of hydration to produce a certain limit expansion, to compensate for the shrinkage of concrete, in ordinary concrete mixed with expansion agent can be equipped with compensation shrinkage concrete and self-stress concrete.
Expanding admixture is mainly used to reduce the dry shrinkage of the allocation of compensation concrete and in order to use the expansion force of the allocation of self-stress concrete, compensation shrinkage concrete for buildings, water tank, cistern, pavement, bridge face plate, underground engineering and other anti-seepage crack.Self-stressing concrete is used in the production of components and products in order to improve the anti-crack strength and anti-crack bearing capacity.
1. Compensation shrinkage concrete, especially for mass concrete due to its large volume, shrinkage stress is also large.Shrinkage-compensated concrete is mainly used in underground, underwater, underwater, tunnel and other structures, mass concrete, reinforced pavement and slab, waterproof between roof and bathroom, component reinforcement, leakage repair, prestressed reinforced concrete, backfilling trough and so on.
2. Self - waterproof concrete, usually used as self - waterproof material for concrete structures.Used for underground, basement, subway and other waterproof projects.
3. Self-stressing concrete, self-stressing concrete can be used in pressurized vessels, water pools, self-stressing pipelines, Bridges, prestressed reinforced concrete, prestressed concrete and all kinds of concrete structures that need to be prestressed.
4. Anti-crack and anti-seepage concrete, mainly used for the maintenance of tunnel, wellbore, tunnel, culvert, support structure concrete, play the role of compacting, anti-crack, anti-seepage.
5. It is suitable for grouting of base of mechanical equipment, pouring of beam and column joints, filling of pipe joints and plugging of water and leakage.
Performance characteristics and technical requirements
1.Expanding admixture has stable shape, no combustion, no chloride ion, and no corrosion effect on reinforcement.
2.Low alkali content, with a total alkali content of 0.5-0.8%, will not cause alkali - aggregate reaction
3. When the product is mixed with 8%-10% and the reinforcement rate is 0.2%-1%, the restricted expansion rate is 2-4*10-4
, and 0.2-0.7Mpa self-stress is generated in concrete, which has little influence on the strength.With the increase of concrete content, the expansion rate increases and the strength decreases slightly.
4. Concrete with this product has a slightly faster slump loss and a slightly shorter setting time, but it does not affect the construction.
5. The 28-day strength is basically not affected, and the strength continues to increase in the later period. The restricted strength of concrete is 10%-15% higher than the free strength.
6. This product is non-toxic and pollution-free, and belongs to the environmental protection product.
Dosage and Usage
This product is powder, the content is generally 8%-12%, the best content is 10%, the low content is 6%-8%, and the same amount is replaced by cement, that is, the internal mixing method.
According to the user material (cement, sand, stone) characteristics and mix ratio, after the test to adjust the content, has achieved the purpose of adaptation.The weighing error is less than 0.5%. Put into the mixer together with other materials and prolong the mixing time by 60 seconds.
Matters need attention：
1. The accuracy of the dosage of expansion agent must be ensured to achieve the effect of compensating shrinkage.
2. The powder expansion agent should be put into the mixer together with other raw materials of concrete, the concrete mixed on site should be extended for 30S compared to ordinary concrete.
3. Concrete distribution and vibration should be carried out in accordance with construction specifications.Vibration must be compact, not leakage vibration, undervibration, overvibration.
4. In order to give full play to the expansion effect of expansive concrete, sufficient wet curing is required, so the maintenance work must be paid attention to
5. It is better to use wood templates to facilitate the insulation of the wall
Package, Storage and Transportation
Package: woven fabric bag with plastic liner, including 25kg/50kg.
Storage: it should be stored in a dedicated warehouse that is well-ventilated and dry. If caking and lumped, just sieve it by 0.63mm mesh or make it into solution, then use it. Usually, its shelf life is one year, if after the expiration date, it can continue to use when the testing results fall within the established range.
Transportation: this product is non-toxic and non- explosive. It can be transported by truck, ship and train.