CONCRETE

1. PORTLAND CEMENT– lime, silica, and alumina

• Adding water causes chemical reaction: hydration

Concrete made of three materials

Concrete made of three materials

2. Water• Amount of water affects the final

strength• Too much reduces strength

Concrete made of three materials

3. Aggregates• Sand or gravel• Improves cement structure

CONCRETE

Bonds with aggregates• initial set: 45 minutes• final set: 10 hours• Final cured strength: 28 days

MORTAR

• Material used to bond masonry units together

• Not structural like concrete

MORTAR

• Bonds are just the opposite of concrete:

• Higher water-cement ratios bond better

Mix 1 part Mix 1 part mortar: 2 mortar: 2 parts sandparts sand

Bricks

Cored brick• cheaper

Bricks

Bullnose brick• Rounded edge

CONCRETE

• Most landscape jobs, 4000 PSI concrete with 3” slump

• Slump is measure of the amount of water in concrete

CONCRETE

ACCESS FOR MIXER• Wheelbarrow

CONCRETE

ACCESS FOR MIXER• Concrete boom

BASE AND REINFORCEMENT

Wiremesh, reduce cracking and strengthen

BASE AND REINFORCEMENT

Fibermesh, tiny strands of fiberglass added to mix

FORMS

• 2x4 most common• Curved sections using flexible plastic

EXPANSION JOINTS

• Absorb expansion of concrete when warm

• Between concrete and a permanent object

EXPANSION JOINTS

½” plastic or fiberboard

POUR

• Screed in sawing motion to the top of the form

FLOATING

• Smoothing surface

• Magnesium, steel or wood float

FLOATING

• Kneeboards to reach center

FLOATING

Bull floating is the initial float• Compacts concrete, brings up water• Reduces cracking

Pouring Concrete

• Forms

Concrete Sidwalk

• Base material– 57 Stone

Concrete Sidwalk

• Wiremesh

Concrete Sidwalk

• Concrete

Concrete Sidwalk

• Screed level with forms

Concrete Sidwalk

• Bull float

Concrete Sidwalk

• Float finish

Concrete Sidwalk

• Contraction joint

CONTRACTION JOINTING

• 3/8” groove across concrete• Controls cracking as slab dries• Cracks will occur on contraction

joints

JOINTING

• While concrete still wet• Or cut after dry

JOINTING

• Can be part of design

Concrete Sidwalk

• Edge

EDGING

• Rounds and smoothes the edge• Done while wet• Reduces chipping

CURING

• Retains heat and moisture– Cover with plastic sheet– Or spray with membrane compound

CURING

• Improves strength and reduces cracking– Slows down drying

• Cover a minimum of 24 hours• Ideally 3 to 7 days

– Until moisture no longer under plastic

Concrete Sidwalk

• Broom finish

Broom Finish

• Broom, texture and non-slip

Broom Finish

• Broom, perpendicular to traffic

Color Concrete

• Dye mixed with concrete or topdressed on surface

Stamping Concrete

• Realistic paver or stone patterns• Stamping Concrete Video• About $8 / square foot

Stamping Concrete

• Colored release agent: colors and keeps concrete from sticking to stamp

Stamping Concrete

Stamping Concrete

• Clean off release agent

Stamping Concrete

Stamping Concrete

Stamping Concrete

Concrete Overlay

• 1/8” layer over existing concrete• Template pattern• About $6 / square foot

• http://www.dbconcretechicago.com/StampedConcretePatterns.aspx

Stenciling Concrete

Stenciling Concrete

• Pour and float

Stenciling Concrete

• Stencil pressed into concrete

Stenciling Concrete

• Color added

Stenciling Concrete

• Stencil removed after curing

Stenciling Concrete

Stenciling Concrete

Stenciling Concrete

Stenciling Concrete

• Stencil removed

Stenciling Concrete

• Debris blown off

Exposed Aggregate

Exposed Aggregate

• Surface, Pea gravel embedded in surface

• Integral, Mixed gravel/concrete stronger bound

Exposed Aggregate

Exposed Aggregate

• Topdressing pea gravel on surface

Exposed Aggregate

• Roll pea gravel into concrete

Exposed Aggregate

• After initial set (2 hours), wash concrete off pea gravel

Exposed Aggregate

• After wash

Exposed Aggregate

• After cleaning After cleaning – Muriatic acidMuriatic acid

Exposed Aggregate VideoExposed Aggregate Video

Engraving Concrete

Acid Staining

• Clean concrete• Spray acid mix

– Chemical reaction with concrete

• Avoid – Muriatic acid treated concrete– Sealed concrete

Acid Staining

• Spray acid stain

Acid Staining

• Baking soda mixture to neutralize after dry time – 2 to 8 hours

Acid Staining

• Seal

Everstone

• Epoxy resin with decorative stone

Salt Finish

Salt Finish

Oystershell concrete

Local concrete for stamping, etc.•http://www.decorativeconcreteofsc.com •http://www.extremeconcretellc.com•http://www.wimp.com/concretetents

• Costs: http://concreteideas.com/how-much-does-decorative-concrete-cost