train the trainer - parking

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MCIA Promotion Group 2014

ASPHALT

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Time to Turn the World Gray!!

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Welcome from the Cost & Miller Team!

Amy Miller, P.E. NRMCA Vice President, National Resources

Tim Cost, P.E., F.ACI Holcim (US), Inc. Senior Technical Services Engineer

Antitrust Policy Statement The National Ready Mixed Concrete Association assigns the highest priority to full compliance with both the letter and the spirit of the antitrust laws. Agreements among competitors that unreasonably limit competition are unlawful under federal and state antitrust laws, and violators are subject to criminal fines and incarceration, civil fines and private treble-damage actions. Even the successful defense of antitrust litigation or an investigation can be very costly and disruptive. It is thus vital that all meetings and activities of the Association be conducted in a manner consistent with the Association’s antitrust policy. Examples of illegal competitor agreements are those that attempt to fix or stabilize prices, to allocate territories or customers, to limit production or sales, or to limit product quality and service competition. Accordingly, it is inherently risky and potentially illegal for competitors to discuss under Association auspices, or elsewhere, the subjects of prices, pricing policies, other terms and conditions of sale, individual company costs (including planned employee compensation), the commercial suitability of individual suppliers or customers, or other factors that might adversely affect competition. It is important to bear in mind that those in attendance at Association meetings and activities may include competitors, as well as potential competitors. Any discussion of sensitive antitrust subjects with one’s competitors should be avoided at all times before, during, and after any Association meeting or other activity. This is particularly important because a future adversary may assert that such discussions were circumstantial evidence of an illegal agreement, when viewed in light of subsequent marketplace developments, even though there was, in fact, no agreement at all. If at any time during the course of a meeting or other activity, Association staff believes that a sensitive topic under the antitrust laws is being discussed, or is about to be discussed, they will so advise and halt further discussion for the protection of all participants. Member attendees at any meeting or activity should likewise not hesitate to voice any concerns or questions that they may have in this regard. Adopted by the NRMCA Board of Directors September 18, 2006.

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Agenda

Establishing and Flipping Concrete Parking Lots

Developing Intersection Overlay Opportunities

Streets and Local Roads

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Goal

Our Goal: To help prepare you to discuss stated market segments to various audiences so that you can be successful in enacting change.

Your Goal: ???

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Establishing and Flipping Concrete Parkings Lots

“ This is the most over-looked area of our business. Everyone in the industry needs to get in the habit of pursuing the parking lots like they do the interior slabs. If we got 50% of the parking lots for which we do the interior work, our business would escalate dramatically.”

- Les Howell, Delta Industries

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What you should know first General Overview of Design and Construction

Approach for given audience WIIFM???

Typical problems/questions that arise Preparing for objections

Resources

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Be Armed with Knowledge – YOU are the Concrete Expert What’s the correct design methodology for

concrete parking lots????

Why this design methodology???

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Designing Concrete Parking Lots (the right way)

ACI 330R-08 The Guide to Design and Construction of

Concrete Parking Lots

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What do designers currently use for concrete parking lots? Usually follow DOT Nothing – No concrete design; Only design in

asphalt DOT guidelines for roadway design – usually

one of the AASHTO guides; Following DOT guidelines – Bad idea!

“What we’ve always used” ACI 330!

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Source of Much of What We Know About Pavement Design

AASHO Road Test Late 50’s and early 60’s Ottawa, Illinois

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CONVENTIONAL PAVEMENT DESIGN USES THE 1993 AASHTO PAVEMENT DESIGN GUIDE Based On Old Technology

AASHTO Guide was developed based on AASHO Road Test in 1950’s

Pavement surface: jointed plain or jointed reinforced concrete with dowels (3500 psi)

Utilized 1 subgrade and 1 base type (highly erodible) PCC pavements failed by pumping

Maximum 1.1 million ESAL applications over 2 yrs

Based on 1 climatic zone - Illinois (wet/freeze) Pavement performance measured by human

perception of ride quality

Many of the 1993 AASHTO Inputs are not measureable

• Initial serviceability • Terminal serviceability • Equivalent Single Axle load - ESAL • Load transfer coefficient - J-factor • Drainage factor • Structural number • Layer coefficient

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AASHTO PAVEMENT DESIGN GUIDE IS NOT RECOMMENDED FOR CONCRETE PARKING LOT PAVEMENTS AASHTO Guide is intended for use on highway pavements

Highway pavements are different than parking lots High speed traffic One-directional traffic

patterns Loading near edge of

pavement Mixed vehicle types Water drains rapidly from

pavement Light poles, Islands are

not on highways AASHTO Guide is currently being revised based on current technology of pavement design

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FOLLOWING ACI 330 GUIDELINES RESULTS IN COMPARABLE, SUPERIOR PERFORMING CONCRETE DESIGNS ACI has developed recommended design

procedure specifically for parking lots

- Recognizes construction integrity of

rigid pavement materials. Recommends reduction or elimination of granular base:

- Potential Savings = 25-35% of total cost.

ACI 330 recognizes parking lots are different than a street/roadway.

Load is in the Interior Primary purpose is to store & move

vehicles Lot may be a water collector May need to accommodate lighting,

islands, landscaping

Given: •Soil Strength •Concrete Strength •Traffic Demand

Determines: •Thickness •Jointing •Reinforcing (opt.) •Subbase (opt.)

History of ACI 330

-Economical 20 Year Design, 95% Reliability -Addresses All Aspects of Concrete Parking Lots

-Based on Unreinforced Concrete Design - Only Document Created Just for Concrete

Parking Lots -THE INDUSTRY STANDARD!!

- 1980s -Complete and Concise for Design

and Construction -Written by Industry Experts - Most Recent Version – 2008

Following a Prior Release in 2001

Why Use It?

Overview of the Document:

-Pavement Design – CH 3 -Materials – CH 4 -Construction – CH 5 -Inspection and Testing – CH 6 -Maintenance and Repairs – CH 7

Specifying and requiring the contents of ACI 330 R-08 gives a designer confidence that many aspects of a concrete parking lot are

addressed.

Designing with ACI 330:

Key Terminology: k – modulus of subgrade or CBR – California Bearing Ratio ADTT – average daily truck traffic MOR – modulus of rupture

Designing with ACI 330:

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ACI 330R-08 Guidelines – Table 3.4

Thickness criteria based on soil support and Average Daily Truck Traffic (ADTT)

MOR, psi:

k = 500 psi/in. (CBR = 50, R = 86) k = 400 psi/in. (CBR = 38, R = 80) k = 300 psi/in. (CBR = 26, R = 67)

650 600 550 500 650 600 550 500 650 600 550 500

Traffic Category

A (ADTT =1) 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.0 4.5

A (ADTT = 10) 4.0 4.0 4.0 4.5 4.0 4.0 4.5 4.5 4.0 4.5 4.5 4.5

B (ADTT = 25) 4.0 4.5 4.5 5.0 4.5 4.5 5.0 5.5 4.5 4.5 5.0 5.5

B (ADTT = 300) 5.0 5.0 5.5 5.5 5.0 5.0 5.5 5.5 5.0 5.5 5.5 6.0

C (ADTT = 100) 5.0 5.0 5.5 5.5 5.0 5.5 5.5 6.0 5.5 5.5 6.0 6.0

C (ADTT = 300) 5.0 5.5 5.5 6.0 5.5 5.5 6.0 6.0 5.5 6.0 6.0 6.5

C (ADTT = 700) 5.5 5.5 6.0 6.0 5.5 5.5 6.0 6.5 5.5 6.0 6.5 6.5

D (ADTT = 700) 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5 6.5

MOR, psi:

k = 200 psi/in. (CBR = 10, R = 48) k = 100 psi/in. (CBR = 3, R = 18) k = 50 psi/in. (CBR = 2, R = 5)

650 600 550 500 650 600 550 500 650 600 550 500

Traffic Category

A (ADTT =1) 4.0 4.0 4.0 4.5 4.0 4.5 4.5 5.0 4.5 5.0 5.0 5.5

A (ADTT = 10) 4.5 4.5 5.0 5.0 4.5 5.0 5.0 5.5 5.0 5.5 5.5 6.0

B (ADTT = 25) 5.0 5.0 5.5 6.0 5.5 5.5 6.0 6.0 6.0 6.0 6.5 7.0

B (ADTT = 300) 5.5 5.5 6.0 6.5 6.0 6.0 6.5 7.0 6.5 7.0 7.0 7.5

C (ADTT = 100) 5.5 6.0 6.0 6.5 6.0 6.5 6.5 7.0 6.5 7.0 7.5 7.5

C (ADTT = 300) 6.0 6.0 6.5 6.5 6.5 6.5 7.0 7.5 7.0 7.5 7.5 8.0

C (ADTT = 700) 6.0 6.5 6.5 7.0 6.5 7.0 7.0 7.5 7.0 7.5 8.0 8.5

D (ADTT = 700) 7.0 7.0 7.0 7.0 8.0 8.0 8.0 8.0 9.0 9.0 9.0 9.0

4.5

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Common Design Questions?

Do I need to include a subbase? What about fibers? Should I include WWM? How important is jointing? What about sealants?

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Concrete vs. asphalt – terminology & loads Subgrade stresses differ considerably.

Concrete Asphalt

incr

easi

ng s

tres

s

subgrade

subgrade

“subbase” layer “base” layers

The load-carrying structure for concrete pavement is primarily thickness.

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Is a subbase layer needed? “Subbase” is a layer of imported or improved

material between the natural site material (subgrade) and the concrete

May warrant consideration if: Construction platform is needed Subgrade is very poor quality Heavy truck traffic & load transfer

concerns Pumping of subgrade is likely

Can result in higher k value for design and slightly thinner section Table 3.2 in ACI 330

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Subgrade k value, psi/in.

Subbase thickness 4 in. 6 in. 9 in. 12 in.

Granular aggregate subbase 50 65 75 85 110 100 130 140 160 190 200 220 230 270 320 300 320 330 370 430

Cement-treated subbase 50 170 230 310 390

100 280 400 520 640 200 470 640 830 —

Other treated subbase 50 85 115 170 215

100 175 210 270 325 200 280 315 360 400 300 350 385 420 490

Table 3.2 – Modulus of subgrade reaction k*

Adjusted k for subbase (ACI 330R-08)

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GUIDANCE ON USE OF A SUBBASE Purpose of Base or Subbase

• Provide uniform, stable, and permanent support • Increase modulus of subgrade reaction (k) • Minimize effects of frost action • Prevent pumping of fine-grained soils • Provide working platform

AASHTO 1993 Manual:

“In cases where design traffic is less than 1 million ESALS, an additional subbase layer may not be needed”

ACI 330R-08:

“It is not economical to use subbase material for the sole purpose of increasing k-values…granular subbases are not normally used for concrete parking lots and should not be used as a construction expedient instead of proper subgrade preparation”

“Normally, pavements that carry less than 200 heavily loaded trucks / day will not be damaged by pumping, especially if speeds are low; therefore, they do not require subbases”

ACI 325.12R-02

“Experience suggests that for pavements that fall into residential classification (22 kip SAL, 34 kip TAL) the use of a subbase to increase structural capacity may or may not be cost effective in terms of long term performance of the pavement”

“With adequate subgrade preparation and appropriate considerations for surface and subgrade drainage, concrete pavements designed for city streets may be built directly on subgrades because moisture conditions are such that strong slab support may not be needed”

NCHRP 27 “It is agreed that base is not required under concrete pavement for low-volume roads and streets except where the percentage of heavy vehicles is unusually high. Pumping is not a problem unless there are large numbers of heavy wheel loads and the pavement foundation is wet”

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What about Fibers and WWM? What’s their purpose? Steel and Macro Fibers (0.008-0.03”); WWM–

Secondary Reinforcement – Tight Cracks! Micro Fibers (<0.004”) – Plastic Shrinkage Crack

Control

“Macro” Fibers

“Micro” Fibers

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When used, the purpose of secondary steel reinforcement is to keep cracks from opening. To do this, it must be located above the mid-thickness.

Steel reinforcement

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It is almost impossible to place rolled wire mesh in the upper thickness where it can function. Rebar on chairs or welded rigid mats perform better if steel is called for. Secondary steel reinforcement is often misunderstood and can rarely be justified in flatwork that is properly jointed.

If steel is used, it should generally be cut at all joints!

Steel reinforcement

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Control the location, width, and appearance of expected cracks

Facilitate construction Accommodate normal

slab movements Provide load transfer

where needed Minimize performance

implications of any random (unexpected) cracks

Objectives of jointing

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NRMCA Design Assistance Program can help!

RECOMMENDED SPACING of JOINTS

FOR CRACK CONTROL THICKNESS, IN. SPACING, FT. 4 8-10 5 10-12 6 12-15 7 14-15 8+ 15

Exception: good design may call for even closer joint spacings due to load transfer considerations.

Spacing of joints based on cracking tendency

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Purpose is to prevent infiltration of water and solids into joint

Topic of some debate Sealants on wide joints are not extremely

effective Most effective is to reduce joint width

Factors to consider in whether or not to seal joints Traffic level Soil types & local performance Subbase use Presence of wind blown debris

JOINT SEALING, FILLING, OR NOT AT ALL?

Recommendations

Contraction joints – Single saw cut 1/8” wide and fill

Isolation joints – Seal over fiberboard (1/4” to ½” wide

Construction joints Butt joints – Single saw cut 1/8” wide and fill or

leave alone Fiberboard – Seal (1/4” to ½” wide)

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Jointing and Reinforcement

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Joint design and layout affects performance

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Specimen stored in water

Drying Wetting / Drying, Heating / Cooling Shrin

kage

Sw

ellin

g

Time

Typical concrete volume changes

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Shrinkage + Restraint = Cracking

Cracking results from combined effects of restraint and shrinkage (drying and/or thermal)…

…whenever resulting tensile stresses exceed tensile strength.

Drying shrinkage and cracking

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Dry Wet

Differential shrinkage, warping / curling of slabs

Can result from differential moisture created by surface drying while the slab bottom remains wet

Can also result from differential temperature Can cause loss of support near panel edges,

movement and faulting at joints, mid-panel cracking

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Control the location, width, and appearance of expected cracks

Facilitate construction Accommodate normal slab

movements Provide load transfer where

needed Minimize performance

implications of any random (unexpected) cracks

Objectives of jointing

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The extent of cracking due to key influences is somewhat predictable; joints can be spaced accordingly.

RECOMMENDED SPACING of JOINTS

FOR CRACK CONTROL THICKNESS, IN. SPACING, FT. 4 8-10 5 10-12 6 12-15 7 14-15 8+ 15

Exception: good design may call for even closer joint spacings due to load transfer considerations.

Spacing of joints based on cracking tendency

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Types of joints in concrete pavement

Control joint

Construction joint

Isolation joint

formed or slipped face

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Aggregate Interlock

Keyways Dowels

TIEBARS ≠ DOWELS! (not used for load transfer)

Load transfer joint details

Not Recommended!

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Round dowels – generally for 8”+ thickness

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Plate dowel systems

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When used, the purpose of secondary steel reinforcement is to keep cracks from opening. To do this, it must be located above the mid-thickness.

Steel reinforcement

Not Recommended!

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It is almost impossible to place rolled wire mesh in the upper thickness where it can function.

Rebar on chairs or welded rigid mats perform better if steel is called for.

Secondary steel reinforcement is often misunderstood and can rarely be justified in flatwork that is properly jointed. If steel is used, it should generally be cut at all joints!

Steel reinforcement

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Today, unreinforced concrete is the most common design for the majority of concrete pavements. Even heavy traffic highways are built without steel reinforcement.

Unreinforced concrete pavement

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Control joint options

Control joints can be made by tooling a groove or pushing an insert into plastic concrete, or by sawing a slot in hardened concrete. The depth of the void must be at least 1/4 of the slab thickness to weaken the section enough to make it crack.

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Tooled control joints

Advantages: Simplest to make Most reliable crack

initiation

Disadvantages: Most noticeable joint Not smoothest for rolling

wheels Not designed for sealers /

fillers

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Saw-cut control joints

Advantages: • Makes best sealant reservoir

• Not as noticeable

• Smooth ride

Disadvantages: • Timing critical to success

• Least reliable crack initiation with gravel aggregates

• More expensive to make

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Saw-cut joints must be made within 4-12 hours after final finishing

This joint was sawed soon enough

This one was sawed too late

Timing of joint sawing – a critical factor

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Early entry “dry cut” saws

Designed to initiate cracks with a shallow cut made much earlier than with wet-cut saws

Timing - the “window of opportunity” is 1 to 2 hours if shallow cuts are used

Also used to cut t/4 or t/3 in normal timing windows

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Construction joints are used between separate concrete placements, typically along placement lane edges. They may use keyways or other features designed for load transfer.

Use of construction joints

Butt joints are recommended for most parking lots where load transfer needs are minimal.

Keyways are now only recommended for entrance drive / street longitudinal construction joints ≥ 10” thick and should be tied.

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Keyways as detailed in earlier documents

D

0.1D

0.2D

1:4 Slope

0.2D

Trapezoidal Half-round

This detail is no longer included in ACI 330R or any ACPA references!

Not Recommended!

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Typical keyway joint performance issues

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…are sometimes called expansion joints but should generally not be used to provide for expansion. They provide no load transfer and should not be used as regularly spaced joints in a joint layout. Their proper use is to isolate fixed objects, providing for slight differential settlement without damaging the pavement.

Isolation joints

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Improper use of isolation joints

If isolation joints are used as routine joints: Slabs “crawl” as isolation

joints compress Adjacent control joints open

and fill with debris No load transfer Failure of sealants Water intrusion

Common issue in construction practice

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Common details for isolation of fixtures Diagonal

Isolation joint

Inlet

Isolation joint

Circular

Isolation joint

Square with Fillets

Isolation joint

Inlet - Round

Isolation joint

Telescoping Manhole

No boxout or isolation joint necessary

None

Isolation joint around perimeter

Square

Isolation joint

Reinforcing bars recommended to hold cracks tight

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Examples - isolation of fixtures

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In many cases, control joints and construction joints may be used interchangeably, depending on the preferred direction of paving lanes.

Load transfer requirements must be considered.

Isolation joints should be avoided in traffic areas except where differential movement or settlement must be accommodated (use thickened edges).

The designer should prepare the jointing plan!

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Joint layout guidelines

Things to Do Match existing joints or cracks Cut at the proper time Place joints to meet in-

pavement structures Adjust spacings to avoid

small panels or angles Intersect curves radially,

edges perpendicular Keep panels square

Things to Avoid Slabs < 1 ft. wide Slabs > 15 ft. wide Angles < 60º (90º is best) Creating interior corners Odd Shapes (keep slabs

square) Offset (staggered) joints Isolation (unthickened) joints

in traffic areas

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Jointing layout – dealing with corners, acute angles, edges with extreme curvature

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Sealing of joints Topic of some debate Sealants must be maintained and

drainage design must be effective Low cost poured sealants not durable Some joint types difficult to seal Factors to consider in whether or not to

seal joints: Traffic level Soil types & local performance Subbase use Presence of wind blown debris

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Concrete Materials

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Concrete materials – what to specify / order

Strength Consistent with design More is not necessarily better

Durability Entrained air for freeze/thaw Sulfates, AAR considerations if

applicable

Other performance requirements Economy Workability Lowest shrinkage potential

Water content, slump Aggregate size & grading

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Entrained air Used to provide freeze-

thaw durability Requires extra QC

attention, testing

Freeze-thaw severity zones

severe moderate negligible

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Pozzolanic benefits Lower heat of hydration, reduced slump loss Consumption of COH, less efflorescence Higher ultimate strengths Greater overall cementitious efficiency

Improved concrete rheology and paste density Lower water demand Improved pumping & finishing Reduced porosity & improved pore character Improved consolidation & formed finishes

Other chemistry interactions, durability benefits Lower permeability Sulfate resistance Mitigation of aggregate reactivity

Environmental benefits Recycled materials – LEED, etc. Reduced consumed energy to produce Lower related CO2 emissions Enhanced reflectivity with GGBFS

Supplemental cementitious materials – “SCMs”

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Construction best practices, options

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Pre-construction conference

Indispensable in avoiding problems and making the project go smoothly

Should cover all functions and responsibilities

Improves project quality Saves time and money

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Compact with proper moisture content Check density with testing or proof rolling Fine grading Remove and replace soft or unsuitable soils Consider subgrade stabilization when

extremely poor soils are encountered Insure adequate surface drainage Water table depth - well below subgrade Uniformity is the key!

Subgrade preparation

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Drainage and subgrade issues: #1 cause of failures

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Compact granular materials near optimum moisture, plastic soils slightly above optimum.

106

103

94

97

100

109

8 10 12 14 16 18 20 22

Max. Density

Opt. Moisture

Den

sity

, lb/

ft3

Moisture Content, %

95% Density

3% 1%

Compaction and moisture-density relationship

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Major projects – use a qualified testing firm

Small projects & quick checks – proof rolling Use if testing is

unavailable or impractical, or to supplement testing

Use a loaded truck

Establish and enforce a criteria

Can help to locate soft spots, stump holes

Monitoring density

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Grading tolerances for the subgrade / subbase

Deviations contribute to variations in concrete thickness and influence drag restraint & cracking

Suggested tolerances: within + ¼”, - ½” of design grade Tight tolerances are more critical for thin slabs

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Forming & placement sequencing

Of the different sequencing options used, the method of paving in alternate lanes (lower photo) has been found most efficient and also helps minimize the adverse effects of shrinkage.

Not Recommended!

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Alternate lane slip-formed placement

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Should the subgrade be dampened prior to concrete placement?

No longer recommended Drier subgrades help to

equalize concrete moisture loss, minimizing slab curling

ACI 330R-08: “normally dry” subgrade

Consider circumstances Not Recommended!

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Good strikeoff / screeding critical for surface tolerances

Select slump based on paving equipment Avoid too much vibration in one place Limit use of bull float; straight-edging is preferred

where vehicle speed > 5 mph Avoid: troweling, use of jitterbugs, any finishing steps

while bleedwater is rising Jointing - saw within critical time window; make cuts /

grooves at least 1/4 of thickness Texturing - use plenty! Curing - timing and effectiveness are critical

Concrete placement & finishing precautions

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Simple strikeoff equipment

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Basic vibrating screeds

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More sophisticated placement equipment

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Construction of “roll-over” integral curbs

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Bull floats vs. straight edges

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Residential finishing methods – not for paving!

Not Recommended!

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No power trowels!

Not Recommended!

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Thickened edges Concrete at pavement edges or along

isolation joints that will support wheel loads should be thickened to provide extra support.

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Example – thickened edge

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Providing surface texture

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Avoiding excessive cracking influences

Monitor evaporation rate & take appropriate steps when extreme

Effective curing Repair subgrade ruts, minimize

other subgrade drag influences Effective curing Extra precautions in cool

weather or with slow strength-gain mixes: apply curing sooner and longer…

Adequate strength before opening to traffic

Effective curing

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Curing effects on performance

Reduces cracking Delay of drying shinkage Minimizes warping

Improves durability and lowers permeability

Facilitates most rapid strength gain

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Spray membrane curing compound - ASTM C 309, white pigmented preferred

Timing is critical - spray immediately after finishing

Suggested application rate: Maximum coverage: 200 ft2 / gal Higher rate (less coverage) for windy

or dry conditions

Curing compound – most common method

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Rules of thumb: Automobile traffic in 3 days Truck traffic in 7 days

Opening can be earlier if adequate strength has developed (2500+ psi)

Fast track techniques can be used to open to traffic in just a few hours

Opening to traffic

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Too soon.

Opening to traffic

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Other information contained in ACI 330R

Inspection and testing Maintenance and repair Suggested joint details Concrete overlays Over existing concrete Over asphalt

Parking lot geometrics

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Parking lot geometrics Small cars

Angle Interlock reduction Overhang

Vehicle projection Aisle width Module widths

θ i o VP AW W1 W2 W3 W4 W5

45 deg 2 ft, 0 in. 1 ft, 5 in. 15 ft, 3 in. 11 ft, 6 in. 26 ft, 9 in. 42 ft, 0 in. 40 ft, 0 in. 38 ft, 0 in. 39 ft, 2 in.




65 deg 1 ft, 2 in. 1 ft, 10 in. 16 ft, 6 in. 14 ft, 0 in. 30 ft, 6 in. 47 ft, 0 in. 45 ft, 10 in. 44 ft, 8 in. 43 ft. 4 in.




Large cars

Angle Interlock reduction Overhang

Vehicle projection Aisle width Module widths

θ i o VP AW W1 W2 W3 W4 W5


50 deg 2ft, 1 in. 2 ft, 4 in. 18 ft, 8 in. 13 ft, 8 in. 32 ft, 4 in. 51 ft, 0 in. 48 ft, 11 in. 46 ft, 10 in. 46 ft, 4 in.







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Summary – so what all is really important here?

Subgrade support, subbase Proper thickness Jointing for crack control Load transfer design Pavement drainage design Materials & methods refined

to minimize shrinkage and warping

Special attention to curing

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Resources

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Audiences

Owners Developers Engineers Contractors

“I can’t afford concrete.”

“I don’t feel comfortable with concrete.”

“My buddy is a site guy.”

“2 inches of asphalt is the same as 6 inches of concrete.”

“I once had a problem with a concrete job.”

“Concrete won’t match existing asphalt on adjacent parking lot.”

“Concrete is hard to clean.”

“Concrete holds my job up.”

“Concrete cracks.”

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Key Points to Address:

Owner/Developer: - You can’t afford NOT to have a concrete

parking lot designed and bid on your project. - Designed (nearly) equivalently, get up-front

cost advantage. - Long-term maintenance benefit

“ We do concrete parking lots because we save money up-front AND our maintenance costs of our concrete lots are 20% of that of our asphalt lots. It’s really a no-brainer, “ - Mississippi Developer

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Key Points to Address: Engineer: - Geo: You can’t afford NOT to design a

concrete parking lot for your client. They are looking to you for guidance. You should have their best interests in play.

- Civil: You should always include your geotechnical engineer’s concrete recommendation. Again, providing the best opportunity for your client. Giving owners options.

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Engineers: - Provide DAP opportunity. Also includes

jointing plans. This is a free NRMCA service to engineers. Helps engineers understand the right way to design.

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Contractor: - Difficult to enact change after-the-fact. Flip

works best with concrete contractor who has a strong relationship with GC.

- Sometimes a proper concrete section can save $ compared to the asphalt section.

- Provides an opportunity for contractor to bring more value to their customer.

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Resources

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Number One Objection????

COSTS TOO MUCH!!!

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HISTORICALLY ASPHALT PARKING LOTS HAVE BEEN LOWER ON INITIAL COST (2004 Data)

Asphalt Paving Design Conventional Concrete Paving Design

USD

Pavement Costs $67,750

• AC Layer1 $17,750

• Gran. Layer2 $50,000

Labor Costs (Included)

Curb & Gutter Cost4 $8,500

Total Initial Cost $76,230

USD Pavement Costs $93,050

• Concrete3 $43,050

• Gran Layer2 $50,000

Labor Costs $45,000

Monolithic Curb & Gutter Cost4

$3,400


Subgrade

2.0” HMAC

Subgrade

5” Concrete

6” Granul

ar Base

(1) AC Price = $45/ton ($13.55/SY Total Installed) (2) Granular Base = $10/SY (3) Concrete = $62/CY($27.61/SY Total Installed)) (4) Additional Curb and Gutter =$10/LFasphalt , Concrete Monolithic

= $4/LF Note: 5000 SY Parking Lot

Concrete paving traditionally been over-designed, having a significant impact on initial costs

110Trucks/Day 13 Trucks/Day Traffic Capacity

6” Granular

Base

6” Granular

Base

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Number One Objection: COST $$$ - Competitive pricing brings all materials costs

down:

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Implementing Industry Recognized Practices, Will Make Concrete More Competitive

Macro Fibers3

Pavement Thickness1

To add impact resistance and crack control

Design thickness to match expected traffic

ACI 330 Guide

Element Objective Recommendation

Use proper joint spacing as prescribed in ACI

330

Do not use artificial minimums

ACI 330 Guide

Cost Impact

3-8%

Granular Base2

Used to prevent pumping

Used as construction platform

Only use in high truck traffic areas -Appropriate

compaction of subgrade

25-35%

10-20%/inch

Welded Wire Mesh

To hold cracks that may occur together

Use proper joint spacing as prescribed in ACI

330 - Eliminate welded wire mesh

7-12%

1) Concrete = $85/CY 2) Granular Base = $15.30/SY 3) Concrete w/ Fibers = plus

$3/CY Note: 5000 SY Parking Lot

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Project Examples:

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Lowe’s Home Improvement – Wilmington, NC

Savings to the owner over traditional concrete design: Undisclosed (reportedly 6-figures)

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Lowe’s Home Improvement – Wilmington, NC

Savings to the owner over traditional concrete design: Undisclosed (reported to be 6-figures)

Subgrade

4.5” Concrete

ACI Concrete Pavement

Subgrade

6” Concrete

4” Stone Base

Subgrade

6” Concrete

Subgrade

8” Concrete

6” Stone Base

Traditional Concrete Pavement

Subgrade

3” Asphalt

Asphalt Pavement

Subgrade

4” Asphalt

6” Granular

Base 6” Stone

Base 8”

Granular Base

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Good Kia – Rock Hill, SC

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Good Kia – Rock Hill, SC

Subgrade

4.5” Concrete


Subgrade

6” Concrete

4” Stone Base

Subgrade

3” Asphalt

Asphalt Pavement

Subgrade

4” Asphalt

6” Granular

Base 8”

Granular Base

Initial pavement costs were comparable

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Toyota of Rock Hill – Rock Hill, SC

6” Cement

Stabilized Subgrade

The Owners Were Willing to Pay $90,000 MORE for Concrete over Asphalt

Subgrade

4.5” Concrete

Original ACI Concrete Pavement

Subgrade

5.5” Concrete

Subgrade

5” Concrete

Subgrade

6” Concrete

Final ACI Concrete Pavement

Subgrade

3” Asphalt

Asphalt Pavement

Subgrade

4” Asphalt

6” Granular

Base 8”

Granular Base

6” Cement

Stabilized Subgrade

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Taco Bell – Lenoir, NC

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Taco Bell – Lenoir, NC

Original Asphalt Pavement Design

Subgrade

5”Concrete

6” Concrete

USD

Asp. Layer 1 $37,450

Gran. Layer2 $14,200

Labor Costs $7,800


USD

Conc. Layer $58,520

Gran. Layer2 $0

Labor Costs $18,430


Subgrade

6” HMAC

6” Granular

Base

ACI Concrete Pavement Design

Subgrade

6”Concrete

7” Concrete

USD

Conc. Layer $70, 240

Gran. Layer2 $0

Labor Costs $18,430


Original Concrete Design

6” Granular

Base

The Owners Paid $17,500 MORE for Concrete over Asphalt

1) AC Price = $80/ton + installation2) Granular Base = $12/ton+installation3) Concrete = $102/CY4) Curb and Gutter =$8.50 /LFNote: 21,143 SF std duty, 11,046 SF heavy duty

Owner Testimonial: “We own more than 50 fast food restaurants. This was our first concrete parking lot and it is the best looking pavement at any of our facilities. The small increase in upfront cost is far less than what it will cost us to maintain an asphalt pavement over the life of the restaurant. We will definitely consider concrete in the future.”

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Dollar General – Pilot Project #1

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Dollar General – Pilot Project #1

Subgrade

4.5” Concrete


Subgrade

5.5” Concrete

Subgrade

5” Concrete

Subgrade

6” Concrete

6” Stone Base

Traditional Concrete Pavement

Subgrade

3” Asphalt

Asphalt Pavement

Subgrade

4” Asphalt

6” Granular

Base 4” Stone

Base 8” Granular

Base

The Developer Saved a NET $9000 Paving with Concrete over Asphalt

$66,800 Concrete: $54,600

Stone: $14,300 Total: $68,900

Concrete: $51,600 Soil: $4,200

Engr. & CMT: $2,000 Total: $57,800

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Other Key Objection:

Construction will take too long.

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Resources

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Resources

www.concretepromotion.org www.nrmca.org Webinars (many free) www.acpa.org Downloadable Pamphlets through NRMCA Design Assistance Program (DAP) Concrete Pavement Analyst Software (CPA)

http://www.concretepromotion.org/

http://www.nrmca.org/

http://www.acpa.org/

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Who can you call for support?

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QUESTIONS??? COMMENTS??

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United Prairie Bank – Worthington, MN

Date Constructed:

1995

Concrete Thickness:

4” Subbase Thickness:

3”

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Medical Office Building – Reno, NV

Date Constructed:

2010

Concrete Thickness:


0”

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Scott Jaguar – Charlotte, NC

20-Year Design Life already performing 25% beyond

design life

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Scott Jaguar – Charlotte, NC

Slab Thickness: 4 inches

Slab Thickness in front of garage bay doors: 5 inches

Exterior Slab on Grade Construction

3500-psi compressive strength placed using truss screed

Pavement Condition Rating: Excellent

Project allowed 20% reduction in light standards

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Good Samaritan Retirement Home – Jackson, MN

Date Constructed:

2001

Concrete Thickness:


3”

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Shopping Mall – Owatanna, MN

Date Constructed:

1998

Concrete Thickness:


3”

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Walgreens – Lantana, FL Date Constructed:

2010

Concrete Thickness:

5”

Subbase Thickness:

0”

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http://www.concretepromotion.org/resources/aci330casestudies.html

Pavement DAP – How do I obtain a

DAP Report?

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http://www.concretepromotion.org/index.html

Pavement DAP – How do I obtain a DAP Report?

http://www.concretepromotion.org/index.html

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Design Services Application Form

Submit application and additional project information to

[email protected]

mailto:[email protected]

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Requested* Information For Design Geotechnical Report

Design/Anticipated Traffic Count

Local Design Specifications

Site Plan

Proposed Asphalt/Concrete Section

Pavement DAP – How do I obtain a DAP Report?

* If information is not available, a design report will be provided based on the information available and assumptions that will be defined in the report.

Pavement DAP – What is in a DAP

Report?

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Designs Provided for: New Pavements, or Rehabilitation of Existing Pavements.

Materials Include:

Conventional Concrete, Pervious Concrete, Roller-Compacted Concrete, or Concrete Overlays.

Pavement DAP – What is in a DAP report?

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Pavement design inputs Site Condition Inputs (fixed, cannot optimize)

Traffic Environmental Conditions Subgrade Support

Project Specific Variables (can be optimized)

Concrete Strength Load Transfer Reliability Others Depending on Design Method Used


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Project Description & Environment

Subgrade Foundation Soils

Traffic Conditions

Pavement Designs

Life-Cycle Cost Analysis (LCCA)

Specifications & Details (Jointing, Curbs, etc.)

Sustainability

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http://www.concretepromotion.org/

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Standard Details That Should be Considered: Joints (Contraction, Construction, Expansion) Curbs, Curbs and Gutters Pavement Junction Concrete Sidewalks Bus Stop Pad Driveways Inlets Pavement/Base Replacement


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Pavement DAP - Guide Specification

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Thank you!

Any questions/comments, please contact Amy Miller at [email protected].

Also, please check our website for upcoming webinars and classes addressing in further depth concrete pavement design.

www.nrmca.org

mailto:[email protected]

http://www.nrmca.org/

History of ACI 330

-Economical 20 Year Design, 95% Reliability -Addresses All Aspects of Concrete Parking Lots

-Based on Sound Engineering - Only Document Created Just for Concrete

Parking Lots -THE INDUSTRY STANDARD!!

- 1980s -Complete and Concise for Design

and Construction -Written by Industry Experts - Most Recent Version – 2008

Following a Prior Release in 2001

Why Use It?

train the trainer - parking

Documents

association meetings

state antitrust laws

association staff

association auspices

asphalt www

antitrust policy statement

associations antitrust

concrete parking lots