Presentations text content in Concrete for Box Culverts – Wet Cast Concrete
Concrete for Box Culverts – Wet Cast Concrete Joseph A. Daczko, FACI – BASF Construction Chemicals
Presentation Outline Many Performance Demands on a Concrete Mixture Wet Cast Box Culverts Specifications and Production RequirementsMain Variables Impacting Hardened and Fresh PropertiesAdmixtures and Concrete Performance Rigid Rugged Resilient 2
Nestle Toll House Cookies – A Recipe 2 1/4 cups all purpose flour 1 tsp baking soda 1 tsp salt 1 cup butter, softened 3/4 cup granulated sugar 3/4 cup packed brown sugar 1 tsp vanilla extract 2 large eggs 2 cups semi sweet chocolate morsels 1 cup chopped nuts
Nestle Toll House Cookies PREHEAT oven to 375 o F. COMBINE flour, baking soda and salt in small bowl. Beat butter, granulated sugar, brown sugar and vanilla extract in large mixer bowl until creamy. Add eggs one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in morsels and nuts. Drop by rounded tablespoon onto ungreased baking sheets. Bake for 9 to 11 minutes or until golden brown. Cool on baking sheets for 2 minutes; remove to wire racks to cool completely. Yields: About 5 dozen cookies
WHAT DO YOU WANT FROM ME? IT’S STILL BLEEDING LOOK AT THOSE BUGHOLES IT’S SEGREGATING!! HAS IT SET YET?? TOO EXPENSIVE IT’S STICKY I WANT STRENGTH!! CONCRETE SHOULDN’T CRACK!!! LOW HEAT!! WATER TIGHT LOW SHRINKAGE I CAN’T FINISH THIS IS IT FREEZE/THAW DURABLE? WRONG COLOR IT’S LOSING SLUMP HOW LONG DOES IT TAKE TO MIX? AIR’S TOO HIGH AIR’S TOO LOW FLEXURAL OR COMPRESSIVE? MODULUS OF WHAT? IT’S GAINING……. SLUMP? HONEYCOMBING?
Concrete for Wet-Cast Boxes Rigid Rugged Resilient 6 3 Buckets of needs Performance in Service Stripping - Production Casting How do we do it? Material Selection Mixture Proportioning Admixtures Placement and Consolidation Techniques
Performance in Service Driven By Specification Strength (5000 psi design)DurabilityFreeze/Thaw DurabilityResistance to Corrosion Rigid Rugged Resilient 7
8 Desired Durability Properties Set Limits
Variables Impacting Compressive Strength Cement Source W/CM Ratio Air Content Time Temperature
Fine Aggregate Impacts W/CM
Compressive Strength- Specification vs Production Targets Rigid Rugged Resilient 11 ASTM C 1433 & 1577 reference design strengths of 5000 psi Demolding strengths needed? – 2000 psi?
Casting – Fresh Properties Rigid Rugged Resilient 12
Slump Impact on Consolidation Effort 2” Slump 5” Slump 7” Slump 10+” Slump
14 Concrete slump, Consolidation Effort and Surface Finish
Slump Measurement
Slump Target Determines Water Content
How Admixtures Facilitate Balancing Performance Demands Low slump SCC Flowing Concrete Moderate slump Concrete Strength W/CM Ratio BUT (-) (-) (-) (-) (-)
Admixtures for Concrete Admixture Definition : a material other than water, aggregates, cementitious materials, and fiber reinforcement, used as an ingredient of a cementitious mixture to modify its freshly mixed, setting, or hardened properties and that is added to the batch before or during its mixing.- ACI Concrete Terminology. ASTM C 494 – Lists 7 basic Types Type A – Water-reducing Type B – Retarding Type C – Accelerating Type D – Water-reducing & retarding Type E – Water-reducing & accelerating Type F – Water-reducing, high range Type G – Water-reducing, high range & retardingType S – Specific Performance
Workability retention without retardation Dosage flexibility – for flexible levels of workability retention A revolutionary new admixture formulated to control the workability (slump) retention of concrete without impacting other properties. Workability Retaining Admixture
DESIRED PROPERTY Workability Workability Retention Finishability Setting High Strength Viscosity Enhancing Rheology Controlling Washout Resistance Color Freeze-Thaw Resistance Alkali-Silica Reactivity Corrosion Protection Drying Shrinkage “Waterproofing” PRIMARY ADMIXTURE Mid- & High-Range WRs Workability Retainer Mid-Range WRs Retarder / Accelerator High-Range WRs Viscosity Modifiers Rheology-Controlling AdmixturesAnti-Washout AdmixturesLiquid-Coloring Admixtures Air EntrainersASR Inhibitors Corrosion Inhibitors Shrinkage Reducers“Waterproofing” Admixtures*
Concrete for Wet-Cast Boxes Rigid Rugged Resilient 21 3 Buckets of needs Performance in Service Stripping - Production Casting How do we do it? Material Selection Mixture Proportioning Admixtures Placement and Consolidation Techniques
Tying it Together Concrete performance demands are varied You must know your local materials Proportioned first to achieve specified hardened propertiesThis may limit certain proportioning flexibilitySet proportions and admixture use to achieve desired production performance CastingStripping strength Rigid Rugged Resilient 22
Nestle Toll House Cookies – A Recipe 2 1/4 cups all purpose flour 1 tsp baking soda 1 tsp salt 1 cup butter, softened 3/4 cup granulated sugar 3/4 cup packed brown sugar 1 tsp vanilla extract 2 large eggs 2 cups semi sweet chocolate morsels 1 cup chopped nuts
Nestle Toll House Cookies PREHEAT oven to 375 o F. COMBINE flour, baking soda and salt in small bowl. Beat butter, granulated sugar, brown sugar and vanilla extract in large mixer bowl until creamy. Add eggs one at a time, beating well after each addition. Gradually beat in flour mixture. Stir in morsels and nuts. Drop by rounded tablespoon onto ungreased baking sheets. Bake for 9 to 11 minutes or until golden brown. Cool on baking sheets for 2 minutes; remove to wire racks to cool completely. Yields: About 5 dozen cookies
Joseph A Daczko – BASF Construction Chemicals 216 233 8293 joseph.daczko@basf.com Rigid Rugged Resilient 25
Concrete for Box Culverts – Wet Cast Concrete
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