High Efficiency CSA Expansive Agent

High Efficiency CSA Expansive Agent is a special calcium sulphoaluminate cement additive. It has efficiency expansion ratio(about 6~8% to ordinary cement ).Its main efficient content is calcium sulphoaluminate and calcium oxide. 

High efficiency CSA expansive agent is designed to mix with ordinary cement as concrete additive. It can minumize the dry shrinkage of concrete, and it can produces self-stress(0.2~0.7mpa) when restrained to prevent cracking as well as waterproofing.

High efficiency CSA expansive agent has gained the national invention patent. The patent No is 02116312.X.

Application:

The properties of expansion is similar to Denka CSA 20# and CSA Power Types or other types of expansion agent like UEA, CEA. And it can be added to concrete or mixed with ordinary cement in construction as below:

1. Railway, tunnel, crack and waterproof layer of the high-rise building.

2. Auto-waterproofing rigidity of surface, impermeability resistance mortar, wet resistance mortar ect.

3. Non-grouting mortar

ect.

Performance anlysics:

Main constitune(%)

Type	SiO2	Al2O3	Fe2O3	CaO	MgO	SO3	TiO2	R2O	Cl-	lgloss
CSA expansive agent type1	5.5-7	5-7	1-2	50-52	2-4	24-27	<1	<=0.3%	<0.05	6-8
CSA expansive agent type2	3-5	8-10	0.5-1.5	51-53	2-4	25-28	<1	<=0.3%	<0.05	6-8

  

Mineral Composition: CaO, CaSO₄, 3CaO·3Al₂O_{3 ·}CaSO4.

Specific Surface Area: 200~400 m²/kg.

Specific Gravity: 2.8~3.0. 

The restrained expansion rate tested under standard condition:

Dosage in OPC (%)	Restrained-expansion rate (%)
	Curing 7d in water	Curing 7d in water then 21d in air
TypeⅠ,7	0.050-0.080	≥0
TypeⅡ,7	0.025-0.045	≥-0.015
TypeⅡ,10	0.055-0.080	≥0

The effect of High-efficiency CSA Expansive Agent dosage on strength of cement mortar:

volume%(in addition)	Limited expansive ratio %
	7d in water	28d in water	28d humidity
7	>0.03	<0.1	>-0.02

 Affect the performance of concrete:

1. It can help the concrete with faster slump loss and shorter setting time;

2. It is able to set up 0.2~0.7mpa self-stress in concrete admixture;

3. No obvious effect on strength of the concrete;

4. High early strength of the concrete than those in other expansion agent;

5. Greatly improve the impermeability resistance of concrete, the impermeability label reach above S30;

6. Greatly improve the freeze resistance and corrosion resistance of concrete;

7. Compensative the dry shrinkage of concrete, preventing the cracking of concrete.

Ect

Compare to other expansive agent:

Dosage:

Strong CSA 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.

Usually,6%-8% by the weight of ordinary cement,which is lower compared with other expansion additives.

Mixing:

Strong CSA expansion 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.

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.