Train the Trainer - Parking
-
Upload
renan-lima -
Category
Documents
-
view
11 -
download
0
description
Transcript of Train the Trainer - Parking
WWW. NRMCA.ORG
MCIA Promotion Group 2014
ASPHALT
WWW. NRMCA.ORG
Time to Turn the World Gray!!
WWW. NRMCA.ORG
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.
WWW. NRMCA.ORG
Agenda
Establishing and Flipping Concrete Parking Lots
Developing Intersection Overlay Opportunities
Streets and Local Roads
WWW. NRMCA.ORG
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: ???
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Establishing and Flipping Concrete Parking Lots
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
WWW. NRMCA.ORG
Be Armed with Knowledge – YOU are the Concrete Expert What’s the correct design methodology for
concrete parking lots????
Why this design methodology???
WWW. NRMCA.ORG
Designing Concrete Parking Lots (the right way)
ACI 330R-08 The Guide to Design and Construction of
Concrete Parking Lots
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
Source of Much of What We Know About Pavement Design
AASHO Road Test Late 50’s and early 60’s Ottawa, Illinois
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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:
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Common Design Questions?
Do I need to include a subbase? What about fibers? Should I include WWM? How important is jointing? What about sealants?
WWW. NRMCA.ORG
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.
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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)
WWW. NRMCA.ORG
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”
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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)
WWW. NRMCA.ORG
Jointing and Reinforcement
WWW. NRMCA.ORG
Joint design and layout affects performance
WWW. NRMCA.ORG
Specimen stored in water
Drying Wetting / Drying, Heating / Cooling Shrin
kage
Sw
ellin
g
Time
Typical concrete volume changes
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Types of joints in concrete pavement
Control joint
Construction joint
Isolation joint
formed or slipped face
WWW. NRMCA.ORG
Aggregate Interlock
Keyways Dowels
TIEBARS ≠ DOWELS! (not used for load transfer)
Load transfer joint details
Not Recommended!
WWW. NRMCA.ORG
Round dowels – generally for 8”+ thickness
WWW. NRMCA.ORG
Plate dowel systems
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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.
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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.
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
Typical keyway joint performance issues
WWW. NRMCA.ORG
…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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Examples - isolation of fixtures
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Jointing layout – dealing with corners, acute angles, edges with extreme curvature
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Concrete Materials
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Entrained air Used to provide freeze-
thaw durability Requires extra QC
attention, testing
Freeze-thaw severity zones
severe moderate negligible
WWW. NRMCA.ORG
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”
WWW. NRMCA.ORG
Construction best practices, options
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Drainage and subgrade issues: #1 cause of failures
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
Alternate lane slip-formed placement
WWW. NRMCA.ORG
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!
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Simple strikeoff equipment
WWW. NRMCA.ORG
Basic vibrating screeds
WWW. NRMCA.ORG
More sophisticated placement equipment
WWW. NRMCA.ORG
Construction of “roll-over” integral curbs
WWW. NRMCA.ORG
Bull floats vs. straight edges
WWW. NRMCA.ORG
Residential finishing methods – not for paving!
Not Recommended!
WWW. NRMCA.ORG
No power trowels!
Not Recommended!
WWW. NRMCA.ORG
Thickened edges Concrete at pavement edges or along
isolation joints that will support wheel loads should be thickened to provide extra support.
WWW. NRMCA.ORG
Example – thickened edge
WWW. NRMCA.ORG
Providing surface texture
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Curing effects on performance
Reduces cracking Delay of drying shinkage Minimizes warping
Improves durability and lowers permeability
Facilitates most rapid strength gain
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Too soon.
Opening to traffic
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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.
50 deg 1 ft, 10 in. 1 ft, 6 in. 15 ft, 9 in. 12 ft, 0 in. 27 ft, 9 in. 43 ft, 6 in. 41 ft, 8 in. 39 ft, 10 in. 40 ft, 6 in.
55 deg 1 ft, 8 in. 1 ft, 8 in. 16 ft, 1 in. 12 ft, 10 in. 28 ft, 11 in. 45 ft, 0 in. 43 ft, 4 in. 41 ft, 8 in. 41 ft, 8 in.
60 deg 1 ft, 5 in. 1 ft, 9 in. 16 ft, 4 in. 13 ft, 4 in. 29 ft, 8 in. 46 ft, 0 in. 44 ft, 7 in. 43 ft, 2 in. 42 ft, 6 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.
70 deg 1 ft, 0 in. 1 ft, 11 in. 16 ft, 7 in. 14 ft, 10 in. 31 ft, 5 in. 48 ft, 0 in. 47 ft, 0 in. 46 ft, 0 in. 44 ft, 2 in.
75 deg 0 ft, 9 in. 1 ft, 11 in. 16 ft, 6 in. 16 ft, 0 in. 32 ft, 6 in. 49 ft, 0 in. 48 ft, 3 in. 47 ft, 6 in. 45 ft, 2 in.
90 deg 0 ft, 0 in. 2 ft, 0 in. 15 ft, 6 in. 20 ft, 0 in. 35 ft, 6 in. 51 ft, 0 in. 51 ft, 0 in. 51 ft, 0 in. 47 ft, 0 in.
Large 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, 4 in. 2 ft, 1 in. 18 ft, 0 in. 13 ft, 0 in. 31 ft, 0 in. 49 ft, 0 in. 46 ft, 8 in. 44 ft, 4 in. 44 ft, 10 in.
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.
55 deg 1 ft, 10 in. 2 ft, 5 in. 19 ft, 2 in. 14 ft, 8 in. 33 ft, 10 in. 53 ft, 0 in. 51 ft, 2 in. 49 ft, 4 in. 48 ft, 2 in.
60 deg 1 ft, 8 in. 2 ft, 7 in. 19 ft, 6 in. 16 ft, 0 in. 35 ft, 6 in. 55 ft, 0 in. 53 ft, 4 in. 51 ft, 8 in. 49 ft, 10 in.
65 deg 1 ft, 4 in. 2 ft, 9 in. 19 ft, 9 in. 17 ft, 0 in. 36 ft, 9 in. 56 ft, 6 in. 55 ft, 2 in. 53 ft, 10 in. 51 ft, 0 in.
70 deg 1 ft, 1 in. 2 ft, 10 in. 19 ft, 10 in. 18 ft, 4 in. 38 ft, 2 in. 58 ft, 0 in. 56 ft, 11 in. 55 ft, 10 in. 52 ft, 4 in.
75 deg 0 ft, 10 in. 2 ft, 11 in. 19 ft, 9 in. 20 ft, 0 in. 39 ft, 9 in. 59 ft, 6 in. 58 ft, 8 in. 57 ft, 10 in. 53 ft, 8 in.
90 deg 0 ft, 0 in. 3 ft, 0 in. 18 ft, 8 in. 24 ft, 8 in. 43 ft, 4 in. 62 ft, 0 in. 62 ft, 0 in. 62 ft, 0 in. 56 ft, 0 in.
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Establishing and Flipping Concrete Parking Lots
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
WWW. NRMCA.ORG
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.”
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
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.
WWW. NRMCA.ORG
Key Points to Address:
Engineers: - Provide DAP opportunity. Also includes
jointing plans. This is a free NRMCA service to engineers. Helps engineers understand the right way to design.
WWW. NRMCA.ORG
Key Points to Address:
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.
WWW. NRMCA.ORG
Establishing and Flipping Concrete Parking Lots
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
WWW. NRMCA.ORG
Number One Objection????
COSTS TOO MUCH!!!
WWW. NRMCA.ORG
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
Total Initial Cost $141,450
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
WWW. NRMCA.ORG
Number One Objection: COST $$$ - Competitive pricing brings all materials costs
down:
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Project Examples:
WWW. NRMCA.ORG
Lowe’s Home Improvement – Wilmington, NC
Savings to the owner over traditional concrete design: Undisclosed (reportedly 6-figures)
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Good Kia – Rock Hill, SC
WWW. NRMCA.ORG
Good Kia – Rock Hill, SC
Subgrade
4.5” Concrete
ACI Concrete Pavement
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
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Taco Bell – Lenoir, NC
WWW. NRMCA.ORG
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
Total Initial Cost $59,450
USD
Conc. Layer $58,520
Gran. Layer2 $0
Labor Costs $18,430
Total Initial Cost $76,950
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
Total Initial Cost $88,670
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.”
WWW. NRMCA.ORG
Dollar General – Pilot Project #1
WWW. NRMCA.ORG
Dollar General – Pilot Project #1
Subgrade
4.5” Concrete
ACI Concrete Pavement
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
WWW. NRMCA.ORG
Other Key Objection:
Construction will take too long.
WWW. NRMCA.ORG
Establishing and Flipping Concrete Parking Lots
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
WWW. NRMCA.ORG
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)
WWW. NRMCA.ORG
Who can you call for support?
WWW. NRMCA.ORG
QUESTIONS??? COMMENTS??
WWW. NRMCA.ORG
United Prairie Bank – Worthington, MN
Date Constructed:
1995
Concrete Thickness:
4” Subbase Thickness:
3”
WWW. NRMCA.ORG
Medical Office Building – Reno, NV
Date Constructed:
2010
Concrete Thickness:
4” Subbase Thickness:
0”
WWW. NRMCA.ORG
Scott Jaguar – Charlotte, NC
20-Year Design Life already performing 25% beyond
design life
WWW. NRMCA.ORG
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
WWW. NRMCA.ORG
Good Samaritan Retirement Home – Jackson, MN
Date Constructed:
2001
Concrete Thickness:
4” Subbase Thickness:
3”
WWW. NRMCA.ORG
Shopping Mall – Owatanna, MN
Date Constructed:
1998
Concrete Thickness:
4” Subbase Thickness:
3”
WWW. NRMCA.ORG
Walgreens – Lantana, FL Date Constructed:
2010
Concrete Thickness:
5”
Subbase Thickness:
0”
WWW. NRMCA.ORG
http://www.concretepromotion.org/resources/aci330casestudies.html
Pavement DAP – How do I obtain a
DAP Report?
WWW. NRMCA.ORG
http://www.concretepromotion.org/index.html
Pavement DAP – How do I obtain a DAP Report?
WWW. NRMCA.ORG
http://www.concretepromotion.org/index.html
Pavement DAP – How do I obtain a DAP Report?
WWW. NRMCA.ORG
Design Services Application Form
Submit application and additional project information to
WWW. NRMCA.ORG
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?
WWW. NRMCA.ORG
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?
WWW. NRMCA.ORG
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
Pavement DAP – What is in a DAP report?
WWW. NRMCA.ORG
Pavement DAP – What is in a DAP report?
Project Description & Environment
Subgrade Foundation Soils
Traffic Conditions
Pavement Designs
Life-Cycle Cost Analysis (LCCA)
Specifications & Details (Jointing, Curbs, etc.)
Sustainability
WWW. NRMCA.ORG
Pavement DAP – What is in a DAP report?
WWW. NRMCA.ORG
Pavement DAP – What is in a DAP report?
WWW. NRMCA.ORG www.concretepromotion.org
Pavement DAP – What is in a DAP report?
WWW. NRMCA.ORG
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
Pavement DAP – What is in a DAP report?
WWW. NRMCA.ORG
Pavement DAP - Guide Specification
WWW. NRMCA.ORG
Pavement DAP - Guide Specification
WWW. NRMCA.ORG
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
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?