American Concrete Institute on the durability of concrete

ACI Quote: “From the materials standpoint, concrete durability is closely linked to concrete microstructure, more specifically to its impermeability.”

Concrete Ingredients:

Portland Cement Water Coarse & Fine

Aggregates Admixtures

Water-Friend AND Foe

Water in USG

0

5

10

15

20

25

30

35

Hydration Water

Free Water

Mix Water

Portland Cement Components:

Tricalcium silicate = 50% Dicalcium silicate = 25% Tricalcium aluminate = 10% Tetracalcium aluminoferrite = 10% Gypsum = 5%

Concrete’s strength is the result of 5 chemical reactions here are 2:Tricalcium silicate + water = calcium silicate hydrate + calcium hydroxide (provides early strength, 7 days) + HeatDicalcium silicate + water = calcium silicate hydrate + calcium hydroxide (provides long term strength, 28 days) + Heat

Water-Friend AND Foe

Wa-ter in

USG

0

5

10

15

20

25

30

35

Free Wa-ter

Mix Water

“Water in concrete becomes an accounting problem—when designing a mix you must know how much water is present and where it all goes. Some is consumed by the cement hydration process, some escapes into the air, some may be absorbed by the ground (if there is no vapor retarder), and some resides in the coarse aggregate. To reduce drying time, mix water must either leave a slab or be chemically or physically bound as quickly as possible.”

Kevin MacDonald, vice president of engineering services for Cemstone, Mendota Heights, MN

Capillary Formation Bleed ChannelsRoute of Moisture Vapor Emission Heavier Materials Settle Water is Pushed out, Bleed Channels Free Water/Moisture Vapor Emission has

Perfect Path to Follow External Intrusion-Perfect Path

Capillary Action

Moisture \Vapor is released by way of the capillary system

Moisture \Vapor can travel into and out of the concrete through the capillary system

Capillaries Vapor Emission

Components: Tricalcium silicate = 50% Dicalcium silicate = 25% Tricalcium aluminate = 10% Tetracalcium aluminoferrite = 10% Gypsum = 5%

WVRA creates the additional CSH needed to: Eliminates the effects of the “free water” Close the capillary system

Solution-Concrete Chemistry

Tricalcium silicate + Mix Water = calcium silicate hydrate (CSH) + calcium hydroxideDicalcium silicate + Mix Water = calcium silicate hydrate (CSH) + calcium hydroxideWater Vapor Reducing (WVRA) admixture + Free Water = calcium silicate hydrate gel (CSH)

CSH Formation

FREEWATER

+ = Calcium Silicate Hydrate (CaSi02)

WVRA

Product cm/s Perms Constant

WVRA5.17E-

11 0.00095.728E-

08

Quality VB2.119E-

09 0.0375.728E-

08Cementitious

Patch6.301E-

09 0.115.728E-

08

Epoxy Topical3.036E-

08 0.535.728E-

08

Internally Ionic Bonded

5.662E-10 0.010

5.728E-08

WVRA

Qualit

y VB

Cemen

titio

us P

atch

Epoxy

Top

ical

Inte

rnal

ly Io

nic Bon

ded

0.00E+00

1.00E-01

2.00E-01

3.00E-01

4.00E-01

5.00E-01

6.00E-01

cm/sPermsConstant

ACI Quote: “From the materials standpoint, concrete durability is closely linked to concrete microstructure, more specifically to its impermeability.”

Benefits of WVRA in Concrete

• Impermeability

Topical Moisture Solution?

ASTM E-960

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

Topical ATopical BWVRA

Flooring Solution Comparison

WVRA Topical Epoxies

Pro-active No VOC’s Warranted

Labor & Material 10 years

No Project Delays Inexpensive ($0.50-

$0.75 sf) Improves IEQ

Reactive VOC’s Warranted

Labor & Material

Massive Project Delays

Expensive ($3-$8 sf) Erodes IEQ

Break Strengths!

7 28 560

1000

2000

3000

4000

5000

6000

7000

8000

9000

733043200

Summary-Admixture Benefits WVRA-Use Free

Water-Close Capillaries Increase Concrete

Durability Sustainability Longevity Avoid needless repairs

Risk Management Tool Eliminate moisture

sensitive flooring failure IEQ Mold & Bacteria

Growth

Regal Cinema-17 Days to Floor Install

Vassar Emergency Medical