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Mixing, Placing and Curing Concrete

Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

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Page 1: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Mixing, Placing andCuring Concrete

Page 2: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 2

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

Page 3: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 3

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

ReadyMixed

Page 4: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 4

Ready-Mixed Concrete

Ready-MixedConcrete

CentralMixing

TransitMixing

ShrinkMixing

Page 5: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 5

Central Mixing

• Approximately 20% of all plants in US• Concrete is completely mixed using a

stationary mixer (drum, paddle, pan)• High production volumes (4000 yd3/day)• Rapid mixing (30 to 120 seconds)• Improved quality control• Can use ordinary dump trucks for transit

Page 6: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 7

Concrete Wet Mix Plant

https://www.easymixconcrete.com/news/the-ready-mix-concrete-process/

Cement andFly Ash Silos

Aggregate Bins

Mixer

Control Room

Page 7: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 8

Concrete Wet Mix Plant

Page 8: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Concrete Slipform Paving

CIVL 3137 11

https://www.gomaco.com/Resources/gp2400.html

Page 9: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Concrete Slipform Paving

CIVL 3137 12

https://www.gomaco.com/Resources/gp2400.html

Page 10: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 19

Shrink Mixing

• Concrete is partially mixed using a stationary plant mixer to reduce volume

• 1 yd3 of fully mixed concrete requires 1½ yd3 of ingredients

• Concrete finishes mixing in a transit mix truck on the way to the job site

Page 11: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 21

Transit Mix Truck

Page 12: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Transit Mix Truck

CIVL 3137 22

https://concretetruckmixer.net/volumetric-concrete-mixer-truck/

Page 13: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 24

Transit Mix Trucks

• 9-12 yd3 mixing drums are typical• Low speed rotation (2 rpm) agitates• High speed rotation (12-15 rpm) mixes• Drum rotates one direction to mix• Drum rotates the other to discharge

Page 14: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Transit Mix Truck

CIVL 3137 25https://en.wikipedia.org/wiki/Concrete_mixer

OPERATIONOF A TRUCK MIXER

Page 15: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 27

Transit Mixing

• Concrete is batched dry at a central plant and placed in a transit mix truck

• Water is either added at the plant or from a tank on the truck itself

• Concrete is mixed entirely in the truck

Page 16: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Dry Batch Concrete Plant

CIVL 3137 28

https://www.cmi-roadbuilding.com/concrete

Page 17: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Dry Batch Concrete Plant

CIVL 3137 29https://www.ceienterprises.com/literature/52-products/concrete-equipment/

Page 18: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 30

Transit Mixing Options

1. Mixing at the batch planta) Mix for 50 revs at 12-15 rpm at batch plantb) Agitate at 2 rpm while in transit

2. Mixing in transita) Mix for 70 revs at 8 rpm while in transitb) Agitate at 2 rpm until ready to discharge

3. Mixing at the job sitea) Agitate at 2 rpm while in transitb) Mix 50-100 revs at 12-15 rpm at job site

Page 19: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 31

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

Page 20: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 32

Placement Methods

WheelbarrowConveyor Belt

ChuteBucketPump

Tuckerbilt

Page 21: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 33

Chute Delivery

Page 22: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 34

Bucket Delivery

Page 23: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 35

Concrete Pumping

Page 24: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 36

Concrete Pumping

Page 25: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 38

Tuckerbilt

Page 26: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 39

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

Page 27: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Consolidation

Consolidation is the process of reducing the volume of voids, air pockets, and entrapped air in fresh concrete, usually through the input of mechanical energy (e.g., vibrating, tamping, or rodding).

CIVL 3137 40

Page 28: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Consolidation

Consolidation is needed because freshly placed concrete is usually honeycombed with entrapped air voids that are larger than the intentionally entrained air voids.

Without consolidation, the concrete will be weak, porous, and poorly bonded to the reinforcement (and unsightly).

CIVL 3137 41

Page 29: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 42

Poor Vibration

Page 30: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 43

Poor Vibration

https://www.construct-ed.com/concrete-vibration/

Page 31: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Tamping

CIVL 3137 44

https://www.concretenetwork.com/concrete/concrete_tools/tampers.htm

Page 32: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Internal Vibrators

CIVL 3137 45

https://civilsnapshot.com/concrete-vibrators-and-its-type/

Page 33: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

External Vibrators

CIVL 3137 47

https://www.mooser.net/en/construction-references/industry-construction/bv-augustin-riederau-e.html

Page 34: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 49

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

Page 35: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 50

Flatwork Finishing Methods

Screedingbringing concrete to correct height

Floatingpushing coarse aggregate below surface

Trowelingbringing bleed water to surface and sealing

Broomingproviding nonskid texture

Page 36: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Flatwork

Flatwork is any poured concrete whose surface is horizontal. This includes floor slabs, patios, sidewalks, driveways, and pavements.

In tilt-up construction, walls are poured flat on the ground then tilted into place, so that is also a form of flatwork.

CIVL 3137 51

Page 37: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Screeding

Screeding removes excess concrete and brings the surface to the proper grade.

Screeding takes place immediately after the concrete is placed and must be completed before excess bleedwater appears on the surface.

CIVL 3137 52

Page 38: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 53

Screeding

Page 39: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Floating

Floating fills voids left by screeding and pushes the coarse aggregate particles slightly below the surface.

Floating leaves a thin layer of mortar at the surface to aid in finishing.

CIVL 3137 54

Page 40: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 55

Floating

Page 41: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Troweling

Troweling brings a small amount of bleed water to the surface to produce a hard, dense finish.

CIVL 3137 56

Page 42: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 57

Troweling

Page 43: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Brooming / Dragging

Brooming and dragging impart a rough texture to the surface of pavement slabs to provide good traction in wet weather.

CIVL 3137 58

Page 44: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 60

Brooming

Page 45: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 61

Burlap Dragging

Page 46: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 62

Concrete Start to Finish

1. Batch2. Mix3. Transport4. Place5. Consolidate6. Finish7. Cure

Page 47: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

Concrete Curing

Curing is essential to developing proper strength and durability by1. Maintaining adequate moisture in the

concrete to hydrate the cement2. Maintaining a minimum temperature

in the concrete so hydration proceeds at an adequate rate

CIVL 3137 63

Page 48: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 64

Poor Curing

Page 49: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 65

Concrete Curing

Replacement Methods

pondingfogging

wet burlapwet straw

wet sawdust

Barrier Methods

plastic sheetscuring compoundsinsulating blankets

Page 50: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 66

Ponding

Page 51: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 68

Ponding

Page 52: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 69

Fogging

Page 53: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 70

Fogging

http://www.concretebridgeviews.com/i80/Article3.php

Page 54: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 71

Wet Burlap / Straw

Page 55: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 73

Wet Burlap and Plastic Sheeting

Page 56: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 74

Plastic Sheeting

Page 57: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 75

Insulating Blankets

Page 58: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 76

Curing Compounds

Page 59: Mixing, Placing and Curing Concrete - Memphis - Mixing Placing Curing Concrete.pdf · Concrete Curing Curing is essential to developing proper strength and durability by 1.Maintaining

CIVL 3137 77

Curing Compounds