Strength-enhancing shrinkage reducing additive CQJSJ accelerates the hydration of Portland cement and alters the morphology and microstructure: • Enhanced early age strength; • Enhanced final strength, 28d compressive strength enhanced by 5%-30%; • Low shrinkage and reduced cracking; • Low permeability; • Good sulfate resistance. Applications: • Prefabricated concrete elements: shortening curing time; • Shotcrete: reduce rebound and enhance early strength.

1. Strength-enhancing shrinkage
reducing additive (促强减缩剂
CQJSJ)
Tangshan Polar Bear Building Materials Co., Ltd

2. Introduction
CQJSJ accelerates the hydration of Portland cement and alters
the morphology and microstructure:
• Enhanced early age strength;
• Enhanced final strength, 28d compressive strength enhanced by 5%-30%;
• Low shrinkage and reduced cracking;
• Low permeability;
• Good sulfate resistance.
Applications:
• Prefabricated concrete elements: shortening curing time;
• Shotcrete: reduce rebound and enhance early strength.

3. Prefabricated concrete elements
Concrete
Mix proportion (kg/m3)
Binder w/b
W OPC S G SP FA GGBFS CQJSJ
C50 150 338 630 1171 7 75 56 0 469 0.32
C50 150 338 630 1171 7 45 56 30 469 0.32
Mix and cast
Finishing
2h
≤60℃
2.5h
Heating
7h
15MPa
2.5h
Constant temp Cooling
2h
Finishing
20min
15MPa@7h
No
CQJSJ
With
CQJSJ
≤60℃
2.5h
Heating
2.5h
Constant temp Cooling
2h
15MPa@4.3h
4h
15MPa
Mix and cast

4. After 8.3h, compressive strength reaches 15 MPa.
Mix and cast
Finishing
20min Covered with plastic sheet
8h 15MPa
Release large amount of heat after 3.5h
Prefabricated concrete elements

5. Prefabricated concrete elements

6. Prefabricated concrete elements

7. No crack
Prefabricated concrete elements

8. Shotcrete
Properties CQJSJ shotcrete Ordinary shotcrete
Initial set./min 2~5 3~6
Final set./min 8~12 8~12
3h comp. /MPa 1.5 无
1d comp. /MPa 12 10
28d comp. /MPa 50 40
Rebound/% ＜10% ＞30%
Permeability P8 P6
Bond strength with
substrate
Good Bad
90d shrinkage/% 0.08 0.15
Cost Save 20m CNY/km -

9. Thanks for your kind attention!
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