Anti-Cracking Shrinkage and Expansion Agent

• Customization: Available
• Application: Concrete Admixtures, Construction Industry, Mortar
• Colour: off-White
• Model NO.: EA-A1
• Transport Package: Bag
• Trademark: JUFU
• Origin: China
• HS Code: 3824409000
• Production Capacity: 3000mt/Years

Product Description

General description
Expansive Agent  is  obtained  by  blending  suitable  natural  anhydrite  with  a  specially  manufactured  clinker which consists essentially of calcium  sulphoaluminate  and  CaO. Expansive  agent  is  always  mixed with ordinary cement. When mixed in the proper proportions with ordinary cement and hydrated,  cement mortar or concrete expands during the early stages of hydration. This expansion, when restrained, makes  it possible  to minimize  drying  shrinkage.  Moreover,  when  the  ratio  of Expansive  Agent  to  ordinary cement is increased its high expansion qualities make it ideal for use in prestressed concrete.
Expansive Agent is being used in all sections of the construction fields and by a wide variety of concrete products manufacturers.
Expansive  Agent  is  manufactured  under  a  strict  quality  assurance  systems  GB/T   19001-2000  (i.e. ISO9001:2000)  and  GB/T  24001- 1996  (i.e.  ISO   14001:1996))  which  accommodates  the  technical requirements of building chemistry formulators.
The properties of Expansive Agent conform to the standards of the manufacturer  and to the Chinese relevant standards.

Characteristics of Expansive Agent
Low alkalinity. Expansive Agent has a very low alkali content (R2O<0.3%) which is beneficial to avoid AAR in concrete.
Short stable stage of expansion. The stable stage of expansion is not more than 14 days, thus the ultimate strength of concrete is not affected.
Low dosage and high expansion capacity. The normal dosage of Expansive Agent is 6~8% by  the weight of ordinary cement, which is lower compared with other expansive additives such as
UEA and CEA (their dosages are about 10~ 12% by the weight of cement) in the market.

Features by using Expansive Agent
Prevents cracking due to drying shrinkage and hydration heats;
Increases the water tightness of concrete and thus is useful for waterproofing buildings;
Enables the manufacture of high strength concrete products through chemical prestressing.

 

Chemical Analysis
Main constituents (%) Based on Percent of Weight
EA-A1

	SiO2	Al2O3	Fe2O3	CaO	MgO	SO3	TiO2	Cl-	Igloss
Usual range	5.5~7	5~7	1~2	50~52	2~4	24~27	<1	<0.05	6~8

EA-A2

	SiO2	Al2O3	Fe2O3	CaO	MgO	SO3	TiO2	Cl-	Igloss
Usual range	3~5	8~ 10	0.5~ 1.5	51~53	2~4	25~28	<1	<0.05	6~8

Mineral Composition: CaO, CaSO4, 3CaO 3Al2O3 CaSO4
Specific Surface Area: 200~400 m2/kg Specific Gravity: 2.8~3.0

Physical Properties
The restrained expansion rate tested under standard condition:

EA-A1

Dosage of Expansive Agent to Ordinary Portland Cement (%)	Restrained-expansion rate (%)
7	Curing in water for 1 day	Curing in water for 3 days	Curing in water for 7 days	Curing in water for 28 days	Curing in air, constant humidity for 21 days
	0.01~0.015	0.02	0.03		>-0.02

 

EA-A2

Dosage of Expansive Agent to Ordinary Portland Cement (%)	Restrained-expansion rate (%)
7	Curing in water for 1 day	Curing in water for 3 days	Curing in water for 7 days	Curing in water for 28 days	Curing in air, constant humidity for 21 days
	0.015	0.025	0.04	0.07	0

 

The effect of Expansive Agent dosage on strength of cement mortar:
       
            The effect of Expansive Agent dosage on strength of cement
            Expansive Agent dosage(%)

      Longitudinal change of mortar:


         Expansive Agent dosage(%)


Directions for Use
1 Dosage Expansive Agent is used as a part of cement, its proportion to ordinary Portland cement depends upon the intended use and the degree of restraint. The proportion of
Expansive Agent to ordinary cement generally used in China is about 6~8%
2 Mixing
Expansive Agent and ordinary cement must be thoroughly and uniformly mixed in a mechanical  mixer  with  aggregate  and  water  for  a  slightly  longer  time  than  normal concrete.
3 Curing
To ensure the proper development of the ettringite needle crystals which are important in

preventing shrinkage cracks which occur during drying period, it is recommended that water be sprayed or membrane curing onto the concrete surface for curing at least  14 days after the concrete is cast.
4 Storage
Expansive Agent is more sensitive to water and moisture than other cementitious material and is therefore packed in completely waterproof bags and should always be kept and
stored in a dry place.