What is Expansive Agent for Concrete ?
  It is one kind of concrete admixtures which, when added to concrete, mortar or paste, produce ettringite, calcium hydroxide or ettringite and calcium hydroxide after hydration reaction, making the concrete volume expand. The normal concrete usually cracks due to shrinkage, causing leakage, poor function and low durability. The key to improve the durability of concrete structure is to control the cracks. The shrinkage compensating concrete obtained by adding expansive agent for concrete at the rate of 6%-12% can greatly improve the waterproofing ability and crack resistance of concrete structures.

The expansive hydration products from the hydration reaction between expansive agent for concrete and cement and water can efficiently compensate the shrinkage of ordinary cement concrete during the water hardening, preventing the cracks caused by such shrinkages. The expansive agent contains no sodium salt and never causes alkali-aggregate reaction. The shrinkage compensating concrete prepared by expansive agent has good durability, steady expansive ability and continuously ascending strength. The expansive agent for concrete can be used to improve the waterproofing ability of the structure (even cancel the application of membrane waterproof materials under certain situation), extend the pitch of post pouring joint and the number of joints can be reduced largely, lower down the chances of cracks of crack caused by dry shrinkages, different temperatures of mass concrete and high-performance concrete and many other reasons.
Technology

1. Using dosage: add 8%-12% of the gel materials.
2. Compressive strength: not lower than base concrete, with same setting time as base concrete but no obvious compact on slump constant.
3. Good adaptability with other chemical additives, low alkali, and remarkable improvement of temperature shrinkage due to hydration heat of gel materials.
4. Performance Index of Shrinkage Reducing Admixture for Concrete.

Item		Index Value
		Type Ⅰ	Type Ⅱ
Fineness	Specific Area/(square meter/kg) >=	200
	1.18mm Sieve Residue/% <=	0.5
Setting Time	Initial Setting Time/min >=	45
	Final Setting Time/min <=	600
Restrained Expansion Rate/%	In Water 7d >=	0.025	0.060
	In Air 21d >=	-0.020	-0.010
Compressive Strength/MPa	7d >=	20.0
	28d >=	40.0
Remarks:The Restrained Expansion Rate in this form is compulsory and others are recommended.

   
Product Uses
 
    With the extraordinary functions of crack resistance, waterproofing, anti-seepage, corrosion resistance and strength reinforcement, the expansive agent for concrete is widely used to prepare shrinkage compensating concrete for concrete self-waterproofing, jointless concrete design and construction of super-long reinforced concrete, mass concrete and other special constructions and parts with requirements of anti-crack and anti-seepage. Following constructions are extremely applicable:

1. Underground structures: underground parking garage, underground air defense facilities, underground storeroom, underground walkway, foundation ditch, pile foundation work and so on.
2. Water pool, swimming pool, treatment tank, water tower, storage tank, grain store and so on.
3. Metro, tunnel, water conservancy and hydropower, marine works, port, water plant, generating plant, reservoir dam and some other waterproof structures.
4. Super long structure floor, stadium stand, radiation shielded concrete structure and so on.
5. Rigid self-waterproof roof, mortar impermeable layer, slurry moistureproof layer.
6. Beam-to-column connection, filling concrete for post-cast strip, mechanical equipment, reinforced second perfusion, pre-stressed concrete.
7. Cement products, self-stressing, pre-stressing and steel pre-stressed concrete, concrete-filled steel tube.
8. Airfield runway, highway pavement, bridge concrete, arch culvert.

Package & Storage

1. Packed by coated woven bags.
2. During storage and transportation, the product should be put in dry place, keeping from moisture and other foreign substances. Different types of products should be stored separately.
3. Handle with caution, protecting the bags from damaging and damping. The heap layer never beyond 10 bags.
4. The shelf life of the product is 6 months under sealed state. Product exceeding shelf life must be retested before using, consultant the manufacturer about the usage.