Product Data Sheet Safety Data Sheet Show all documents

SikaFlow®-640

(formerly MFlow 640)

GROUT ACCELERATOR FOR SIKAFLOW® 648/649/678

When SikaFlow®-640 is added to SIKAFLOW®-648, SIKAFLOW®-649 or SIKAFLOW®-678, it accelerates the cure rate at low temperatures. SikaFlow®-640 should be used in temperatures below 60 °F (16 °C). 

  • Accelerated cure rate enables cold-weather applications
  • Early strength development facilitates early return to service
Product Data Sheet Safety Data Sheet Show all documents

Usage

  • Where heating exterior spaces is impractical
  • When temperatures fall below 60 °F (16 °C)
  • Where high early strengths are required
 

Advantages

  • Accelerated cure rate enables cold-weather applications
  • Early strength development facilitates early return to service

Packaging

1 quart can

Product Details

Product Information

Shelf Life

1 year when properly stored

Storage Conditions

Store in unopened containers at 60–80°F (16–27°C) in clean, dry conditions.

 
Technical Information

Compressive Strength

(ASTM C 579, Method B, modified 2 by 2" cubes)

Before mixing, all materials were conditioned for 24 hours at the respective cure temperatures given below.
 

Tests Conducted with SikaFlow®-648
Material cured at 50°F (10°C)

Cure Time

Results

Hours

Non-Accelerated  Accelerated  Hours psi (MPa)

Accelerated  Hours psi (MPa)  psi (MPa)

24

750 (5)

6,400 (44)

72

10,500 (37)

12,000 (82)

168

12,300 (84)

13,300 (91)

Tests Conducted with SikaFlow®-678
Material cured at 50°F (10°C)

Cure Time

Results

Hours

Non-Accelerated  Accelerated  Hours psi (MPa)

Accelerated  Hours psi (MPa)  psi (MPa)

24

 -

3,500 (24)

72

5,400 (37)

8,500 (58)

168

 8,500 (58)

9,500 (65)

Tests Conducted with SikaFlow®-649
Material cured at 40°F (4°C)

Cure Time

Results

Hours

Non-Accelerated  Accelerated  Hours psi (MPa)

Accelerated  Hours psi (MPa)  psi (MPa)

16

 -

 - 

24

 - 

100 (0.7)

48

800 (5.5)

4,000 (27.6) 
723,900 (26.9)8,700 (60.0)
965,000 (34.5)9,400 (64.8)
1206,800 (46.9)11,400 (78.6)
1447,100 (49.0)12,000 (82.7) 
1688,000 (55.2)13,100 (90.3)

Material cured at 50°F (10°C)

Cure Time

Results

Hours

Non-Accelerated  Accelerated  Hours psi (MPa)

Accelerated  Hours psi (MPa)  psi (MPa)

16

 -

 - 

24

 - 

3,900 (26.9)

48

4,900 (33.8)

12,400 (85.5)
729,200 (63.4)14,000 (96.5)
9611,500 (79.3)15,500 (106.9)
12012,800 (88.3)17,000 (117.2)
14414,500 (100.0)17,400 (120.0)
16814,800 (102.0)17,400 (120.0)

Material cured at 60°F (16°C)

Cure Time

Results

Hours

Non-Accelerated  Accelerated  Hours psi (MPa)

Accelerated  Hours psi (MPa)  psi (MPa)

16

 -

6,800 (46.9)

24

2,600 (17.9)

10,500 (72.4)

48

9,000 (62.1)

13,000 (89.6)
7213,500 (93.1)16,000 (110.3)
9616,500 (113.8)17,500 (120.7)
12017,200 (118.6)17,700 (122.0)
14417,400 (120.0)18,000 (124.1)
16817,400 (120.0)18,000 (124.1)


Temperatures vary so radically (day vs. night, atmospheric vs. metal surface) that field judgment must still be used. When struck with a hammer, cured grout should have a solid, almost metallic feel.

Application

Consumption

Coverage

Order 1 quart can of SikaFlow®-640 for each full-size kit of SikaFlow®-648 (1.7 ft3), SikaFlow®-649 (1.7 ft3) or SikaFlow®-678 (1.8 ft3)
Application steps

NOTES ON INSTALLATION

For Best Performance:

  • Adding Accelerator does not improve the workability of grouts in cold-weather applications.
  • For professional use only; not for sale to or use by the general public.
  • Make certain the most current versions of the product data sheet and SDS are being used; visit usa.sika.com to verify the most current version.
  • Proper application is the responsibility of the user. Field visits by Sika personnel are for the purpose of making technical recommendations only and are not for supervising or providing quality control on the job site.

APPLICATION

  1. Add 1 can SikaFlow®-648, SikaFlow®-649 or SikaFlow®-678 Part B and 1 can SikaFlow®-640 to the pail of SikaFlow®-648, SikaFlow®-649 or SikaFlow®-678 Part A, and stir for 3 minutes. Use immediately. Do not let stand for more than 2 minutes before placing.
  2. Proceed with grouting according to directions in the SikaFlow®-648, SikaFlow®-649 or SikaFlow®-678 product data sheet.

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