Mass Concrete Pour Challenges

Max Temp 160F

Max Differential Temp 55F

Special Projects Require

• <160F Peak Temp- Very Difficult!• <55F Placement Temp- Very Costly!

Cool Mix Design with inert Slag / FlyAsh (30-70%)

• Inconsistent Materials and Results• Variations in Supply

Reduce Thermal Differential Within the Mass Pour

Typical Mix6 Bag, 6 Slump, 6 Air576 Pounds of PortlandPeak Temps 140-170F+Peak Temps in 12-40 HrsFast High TempsRapid Heat of HydrationThermal Control Needed

Current Mass Concrete PoursTypical Temperature Results

Core and Surface Temperature Logging Needed for Successful Pours

Industry Needs

Provide an Liquid Additive Product for Concrete to Limit Curing Temperatures to Safe Levels

Simple, Repeatable, Reliable Product to

• Control Hydroxide Formation and Excessive Heat

• Enhance Strength

• Improve Shrinkage

• Improve Porosity

• Improve Freeze/Thaw Resistance

• Reduce thermal cracking, curl and distortion

Concrete Technology In Mass PoursToday’s cement and concrete chemistry essentially unchanged since 1800’s

High Exotherms from High Heat of Hydration are typical today in Mass Pours

Attempts to Mitigate today by:

• Cooling/Refrigerating the aggregates

• Cooling coils and chiller bundles embedded in the concrete

• Adding ice to the wet mix

• Pumping liquid Nitrogen into the wet mix prior to pour

• Adding fly ash and/or slag to displace reactive components

Unfortunately all of these approaches are often not successful

CoolCure Technology

International Patent PCT US15/11849

CoolCure is an admixture that:

➢ Generates much less heat during curing

➢ 40 to 100% Stronger

➢ More freeze-thaw stable

➢ Increased compatibility with steel reinforcement

➢ And much more….

CoolCure Key Features

● Greatly reduced exotherm during curing● Reduced internal stresses in cured concrete● Compatible with existing equipment and

processes● Minimizes/eliminates many countermeasures

and costly thermal planning/simulation needed with mass pours today

● Greatly reduces/eliminates risk of a disastrous or failed mass pour

CoolCure Chemistry

• Generates less Ca(OH)2 as a reaction byproduct

• This greatly reduces the exotherm

● More efficiently converts available calcium into CSH for increased concrete/cement strength

● Reduces surface tension and fully wets-out portland cement – no “cannon balls”

Tricalcium silicate + Water ---> Calcium silicate hydrate + 3 Calcium hydroxides + high heat

2 Ca3SiO5 + 7 H2O ---> 3 CaO.2SiO2.4H2O +

3 Ca(OH)2 + 173.6kJ

Phase 1 Chemical ReactionHydration of Tricalcium

Dicalcium silicate + Water ---> Calcium silicate hydrate + Calcium hydroxide + lower heat

2 Ca2SiO4 + 5 H2O--->

3 CaO.2SiO2.4H2O + Ca(OH)2 + 58.6 kJ

Phase 2 Chemical ReactionHydration of Dicalcium

Phase 1 reaction acts like Phase 2 reaction

Reduced calcium hydroxide and heat generation ... only 58.6 kJ vs. typical 173.6kJ exotherm

Tricalcium silicate now reacts like Dicalcium silicate -This results in a lower exotherm and a lower calcium hydroxide generation

CoolCure Technology

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Logger Temperatures for CONT INMax Delta Temp: 59.4 °F @ 17 HrsMin Temp: 53.6 °F @ 0 Hrs, Max Temp: 118.4 °F @ 16.27 HrsLogger Start Date: 3/3/2014 11:21:29 AMLast Download Date: 3/13/2014 12:42:39 PM

Cure Test Indoor Pour Wood Formed 4’ Cube – 3/13/14

6 Bag Mix with NTS CoolCure peak84.2F at 39 hrs in center of cube

6 Bag Mix – Control peak temp 118.4F at 17 hrs in center of cube

Testing Performed at PSI Cleveland in 2014 ASTM C-39 Compressive Strength Testing – Fully Hydrated

7 Days 14 Days 21 Days 28 Days

6 Bag Mix –control

4560 psi 5290 psi 5325 psi 5710 psi

NTS –CoolCure6 Bag Mix

3445 psi 6185 psi 7745 psi 7990 psi

● Less heat generated during cure reduces thermal expansion of the concrete as well as shrinkage during cooling stage, thereby minimizing internal residual stresses in the structure – less cracks, curl and distortion

● Anti-freeze properties … the premix has remained liquid down to zero F and below… need more testing to establish exact freeze point but successful pours have been done at 13°F

● Can be implemented in existing cement mixing facilities and trucks.

● CoolCure components are all commercially available and economic

CoolCure Concrete Technology Advantages

Conventional vs. CoolCure

• As conventional concrete sets, bleed water is expelled leaving behind extensive networks of micropores and channels

• CoolCure concrete generates zero surface bleed water which greatly reduces porosity

• CoolCure concrete entrains less free water to better resist freezing and fire induced spalling

• Also, CoolCure offers more effective bonding of aggregate through enhanced wetting

CoolCure Reduces Delayed ASR

● Conventional concrete pH will vary from 12.5 to 13.5+

● Delayed ASR occurs whenever concrete pH exceeds 12.5

● CoolCure Technology Concrete pH is <12.4

NTS Concrete Freeze Thaw TestingASTM C-866A weight loss @ 302 freeze/thaw cyclesTesting performed by PSI labs in Cleveland on 2/6/14

Wt. Lost Percentage Lost

Control 6 Bag 18.0 g. 0.24%

NTS 6 Bag Mix 3.0 g. 0.04%

● Hot loads are eliminated and in warm climates also no need to deliver and pour at night

● Cement plant delivery radius and truck fleet operating radius could be increased significantly. Don’t have to invest in new mix plants on distant job sites

● Enables low heat in mass pours without the use of cooling

● No waiting for bleed water for finishing operations

● Reduced labor cost from more efficient finishing operations

CoolCure Exploits Phase 2 Reaction

CoolCure “Green” Technology

● With increased calcium conversion to CSH, and reduced heat and internal stresses, NTS technology yields concrete with 40% to 100% higher strength

● NTS technology can reduce the amount of Portland cement required. ie. 4000 PSI reducing from 6 bags to 4 bags or less.

● With cement production accounting for man made CO2

generation, CoolCure offers the ability to significantly reduce the amount of portland cement used worldwide would greatly impact global man made greenhouse gas output.

● Additionally the minimization/elimination of cooling required for mass pours will result in significant energy savings and greenhouse gas reductions.

Overall CoolCure Technology

● Low Heat –Controlled Curing

● No Thermal Cracking

● Reduced Concrete Porosity

● Reduced Concrete Curing Shrinkage and Internal Stresses

● Lower Material Costs with No Slag/No Fly Ash needed

● Lower Construction Costs

▪ Simpler Thermal Planning▪ No Cooling Pipes▪ No Insulating / Heating Forms▪ No Pre-Treating of Aggregates▪ No Post Cooling Batches via Chillers

• A Greener Product