SEALCOATING PRINCIPLES for CONTRACTORS

PROTECTION & PRESERVATION OF ASPHALT SURFACES

part i-general

PRESENTED BY Girish C. Dubey

President, STAR, INC.

1

OBJECTIVES

1. To understand Asphalt Pavements , their;

a. Basic construction and make up,b. Strengths and weaknesses,c. Why they have to be protected ?d. Which types of pavements can be protected?e. How can they be protected ?

Concept of SEALCOATINGS

2. Overall Savings and value to the property owner.

2

OBJECTIVES

3. Sealcoating Materials:a. Refined Tar Based sealcoatings (RTS)b. Asphalt Emulsion Based sealcoatings (AE).

4. Sealcoating Application: a. Equipment

b. Mix Design compositionsc. Application details and Cautions

5. Drying and cure of sealcoatings

6. Good Sealcoating Practices

7. Do and Don’ts.

8. Trouble-shooting

9. Commonly asked questions. 3

ROAD CONSTRUCTION

A. PRIOR HISTORY OF ROAD CONSTRUCTION:

Constructed with Clay, Limestone, Rocks-

Functional but severely damaged by rain:

The aggregates absorbed water, became soft and lost their strength to support loads. Roads were destroyed in no time.

B. ASPHALT AS A PAVING MATERIAL-

Used since 18th. century A by-product of petroleum refining process was plentiful and had excellent;

Adhesive (Gluing) properties, Water Proofing (repellency)

will not let water penetrate the pavement and damage it. Flexibility- Pavement surface will flex under traffic without

cracking.

ASPHALT KEPT WATER OUT OF THE PAVEMENTS, KEEPING THE BASE DRY AND FUNCTIONAL

4

WHAT IS ASPHALT

IT IS A BY-PRODUCT OF PETROLEUM REFINING PROCESS.

CRUDE PETROLEUM- ORIGINATED FROM THE DECAY OF MARINE LIFE OVER MILLIONS OF YEARS.

CRUDE PETROLEUM

REFINIG PROCESS REMOVE LIGHTER FRACTIONS:

SOLVENTS, GREASE, OIL….

RESIDUE: ASPHALT

ASPHALT IS A VERY COMPLEX MIXTURE OF OVER 5000 COMPOUNDS.

WHAT IS ASPHALT ?

5

ASPHALT PAVEMENTSWHAT THEY ARE AND HOW ARE THEY CONSTRUCTED ?

Pavements are the solid floor of any construction that carries traffic;

VEHICULAR : High Traffic :Highways, Roads, Streets, Low traffic : Airport runways, aprons, parking lots, driveways, service

stations.. PEDESTRIAN: Walkways, Play Grounds, Schools, etc.

CONSTRUCTIONThe earth is removed and - Filled with large aggregates (gravel, rocks, limestone- Base course- Filled with smaller aggregates- Sub-base course- Covered with hot molten asphalt (5-10% By weight) mixed with finer aggregates- top course.

THIS TOP LAYER, SO TO SPEAK , IS THE " ROOF OF THE PAVEMENT".

TOP COURSE, Asphalt Hot-Mix.

SUB-BASE COURSE

BASE COURSE

THE CONSTRUCTION VARIES WITH THE TRAFFIC LOAD REQUIREMENTS.

6

ASPHALT AS A PAVING MATERIAL

SHORTCOMINGS 1. DETERIORATES UNDER SUN'S ULTRAVIOLET RAYSUnstable (aliphatic) compound in asphalt breakdown.

2. Attacked or Dissolved by:

a. DISSOLVED BY PETRO-CHEMICALS:GASOLINE, OILS, FATS, GREASE ETC. Same origin-crude petroleum. Natural Affinity-Co-exited in nature over mils. Of yrs. Like dissolves like.

b. DEICING SALTS- Attack unstable compound in asphaltc. WATER- Strips asphalt form aggregates.

7

HOW ASPHALT BREAKS DOWNThe top layer degrades from the elements soon

after the asphalt installation.

Surface cracks develop, Asphalt becomes brittle, water seeps in, and cracks widen,

damaging the base.

Trapped water weakens the foundation and further damage occurs under traffic and

seasonal freeze / thaw cycles.

Further asphalt damage is done over time. Chunks of asphalt begin to break

away and potholes quickly develop.

End of The Pavement 8

HOW TO PROTECT ASPHALT PAVEMENTS :-

APPLY A COATING ON THE ASPHALT SURFACE THAT WILL:

FORM A BARRIER COAT TO SHIELD THE ASPHALT PAVMENT FROM THE ELEMENTS THAT DESTROY ASPHALTSUN’S UV RAYS,GAS, OIL,FAT AND PETROCHEMICALS, WATER AND DE-ICING SALTS

ULTRAVOILT (UV) RADIATIONS SOLVENTS

WATER & DE-ICING SALTS FUEL, OIL & FATS

SEALCOATING

ASPHALT PROPERTIE

STAY "SEALED IN“.

SEALS IN THE EXCELLENT PROPERTIES OF ASPHALT

SEALCOAT !

9

REGULAR MAINTENANCE PROGRAMS:

1. SAVES MONEY FOR THE OWNER; PAVEMENT LIFE CAN BE EXTENDED BY OVER 300%

2. PROTECTS AND PRESERVES THE ASPHALT PAVEMENT.

3. BEAUTIFIES THE PAVEMENT & ENHANCES THE BUISNESS IMAGE.

4. CLEANING BECOMES EASIER; RAIN WASHES OFF THE DIRT AND DEBRIS EASILYTRAFFIC MARKINGS LAST LONGER.

BENEFITS OF SEALCOATINGS

10

Pavement Preservation ProgramCost-Benefits Analysis

11

ECONOMICS OF SEALCOATINGREGULAR MAINTENACE RESTORES LOST PROPERTIES

12

2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 20210.00

10.00

20.00

30.00

40.00

50.00

60.00

70.00

80.00

Economics of SealcoatingUn-maintained Asphalt costs 3 times

more than a maintained lot

Sealed Unsealed

Cu

mu

lati

ve

Co

st

($)

pe

r S

q.

Ya

rd

13

DO ALL PAVEMENTS NEED SEALCOATING ?

MAY NOT BE NEEDED

HIGH TRAFFIC BEARING PAVEMENTS HIGHWAYS, ROADS, STREETS

THE ADVANTAGE- The kneading action of the traffic.

Brings up fresh asphalt to the surface.

The breakdown is not localized.

DESPERATELY NEEDED

LOW TRAFFIC, NON-TRAFFIC BEARING PAVEMENTS:Lack of the kneading action of traffic.

Driveways Fast food

Parking Lots Shopping Malls

Gas Stations Schools………….

14

SEALCOATINGS ARE WATER-BASED COATINGS,

MADE BY DISPERSING: (Batch or Mill process)

1. Refined Tar (RTS) or Asphalt (AE)2. Water3. Clays and 4. Surfactants, Emulsifiers, Polymers.

WHAT ARE SEALCOATINGS ?

15

WHY WATER-BASED?

1. SAFE TO HANDLE AND STORE. 2. NON-FLAMMABLE 3. EASE OF WATER CLEAN UP OF TOOLS, 4. NO SOLVENT FUMES OR HAZARDS OF SOLVENT

5. EASY TO APPLY WITH BRUSH, SQUEEGEE

APPLICABLE SPECIFICATIONS

ASTM, 5727-00,U.S. FEDERAL AVIATION ADMINISTRATION (FAA SPECS.)ASPHALT SEALCOATING MANUFACTURERS

ASSOCIATION (ASMA)COMMERCIAL SPECIFICATIONS

WHAT ARE SEALCOATINGS ?

Now you knowWHAT SEALCOATINGS DO?

1. Protect the Asphalt pavements from:

Sealcoats form a barrier coat to shield asphalt pavements from The damaging elements;

Breakdown under sun’s UV radiation, Oxidation, De-icing salts and water Gasoline, oil, fats, etc., Petrochemicals, anti-freeze, etc.

2. Extends the life of the pavement by avg. 3 times. Seals the asphaltic oils in the pavement and keeps them functional (flexible) for a long time.

3. Reduces overall up maintenance cost of the pavement.4. Improves the curb appeal.5. Adds to the over-all value of the property.

17

DO NOT OVERSELL SEALCOATINGS!!

1. Sealcoatings are not designed to repairthe pavement defects

Cracks, surface or structural. Alligatored cracks. Lose chunks of asphalt, Deteriorating shoulders.

2. Do not over-promise, sealcoating will make the pavement look like new.

3. Do not sealcoat over Gravel or dirt roads Wood Gilsonite coated pavements

PLEASE !PLEASE!! PLEASE !!!

18

What are pavements, How asphalt Pavements are constructed What is asphalt- Its strengths and weaknesses How asphalt can be protected- SEALCOATINGS ! Sealcoatings- Protects & Preserves asphalt Extend the life of asphalt pavements by more than 3 times. Costs Less than 1/3 the cost. Of pavement replacement.

Ready to sealcoat ? Yes, You Are !

Lets Get Started !!

Now You Know The Basics !

19

SEALCOATING PRINCIPLES for CONTRACTORS

PROTECTION & PRESERVATION OF ASPHALT SURFACES

part iI- APPLICATION

PRESENTED BY Girish C. Dubey

President, STAR, INC.

20

SEALCOATING APPLICATIONSequence, Steps, Procedure & Precautions

SEQUENCE MEASURE, CALCUALTE, COST MATERIAL,

O/H, % PROFITS . BID COMPETITIVELY. RECALCUALTE DEVELOP LOGISTICS-CREW, TOOLS, SUPPLIES. MOBILIZE –PERSONNEL, MATERIALS, EQUIPMENT.

PAVEMENT PREPARATION- TRIMMING, CLEANING, REAIRS, ETC. SEALCOATING APPLICATION BLOCK OFF SEALED AREAS, OPEN AS AGREED

DEMOBILIZE-EQUIPMENT. LEAVE A SIGN. NO TRASH NO DEBRIS COLLECT PAYMENT AS AGREED.

21

SEALCOATING ESSENTIALSMaterials, Equipment, Procedures & Precautions

22

MATERIALSSEALCOATINGS :Good Quality, Must Meet

Applicable Specifications.WATER: Clean, Potable.

SAND: Clean, Quarts, Angular, 50-70 MeshADDITIVES: As Recommended.

INSTRUCTIONS FROM SEALER SUPPLIER. DETAILS ON;

MIX DESIGN- Proportions of Sealer, Water, Sand and Additives.

PAVEMENT PREPARATION- Cleaning, Spot Priming, Patching and Crack filling, Patching.

APPLICATION RATES- Coverage Rates. PRECAUTIONS- Application, Handling and Storage.

Must read MSDS

SEALCOATING APPLICATION

23

SEALCOATING MIX DESIGNSEALER IS GENERALLY SUPPLIED AS A CONCENTRATE.

Prior to application, It is mixed with:

WaterSand/AggregateAdditive

In specified proportions. That is called a Mix Design,

The quantities are denoted as % of Undiluted Sealer,With sealer being 100%.

Manufacturers recommend a specific mix design for agiven job.

SEALCOATING APPLICATION- MATERIALS

24

SEALCOATING APPLICATION- MATERIALS

1. WaterAchieves proper fluidity

Expressed as % of sealer

Clean, Potable and Free of salt

2. Sand/Aggregates Adds traction & appearance,

Fills minor surface cracks

Expressed as lbs./Gallon of sealer

Must meet specs.

3. Additives Fast/Uniform drying

Sand suspension and anchoring

Improves chemical and UV resistance

Expressed as % of sealer

25

SEALCOATING APPLICATION

A TYPICAL MIX DESIGN

Sealer (RTS) 100 Gals.Water (25-30% dilution) 25-30 gals.Sand (2-3 lbs./gal) 200-300 lb.Additive (2-5%) 2-5 gal.

Sealer is always used as the base @ 100

Quantities of other materials are

Calculated using sealer @ 100

Mixing has to be thorough.

Hand Mixing may not be enough. Improper mixing –Poor Performance .

26

SEALCOATING APPLICATION- MATERIALS

Hazards in Altering Mix Designs

FOLLOW THE MANUFACTURERS’S INSTRUCTIONS

Watera. Too much- Will reduce the dry film thickness- Poor performance.

b. Too little- Poor flow of the mix, too much sealer may cause tracking- waste of money

Sand/Aggregatesc. Too much (over 5 lb./gal) – Reduced flexibility, may cause pre-

mature surface cracks. Excessive amount-may cause peeling.

d. Too little or none- Uneven appearance, may affect slipperiness

Additivese. Too much (over recommended amount)- May destabilize the

sealer mix. Waste of money.

f. Too little- May be ineffective for the intended purpose.

27

COVERAGE RATES

Definition ~ Expressed in 2 ways1. Gallons of conc. Sealer needed cover One (1) sq. yard.

2. Square feet covered by One (1) gal of conc. Sealer.

Commonly Expressed as Gallon/sq. Yard.

Standard Coverage Rates

Commonly calculated for two (2) coats of sealer 1st Coat applied @ 0.10-0.12 gal. conc. Sealer/sq. yd.

2nd Coat, applied @0.08-0.10 gal. conc. sealer/sq. yd.

T Total of two (2) coats = 0.18-0.20 gal. Of conc. Sealer /sq. yd.

SEALCOATING APPLICATION- MATERIALS

28

JOB CALCULATIONS1. Calculate the area Assume 10,000 sq. yd.

2. Calculate total undiluted sealer needed @ 0.18 to 0.20 gals. Per sq. yd

Application/ Conc. Sealer

Coverage rateRate

Gal/Sq. Yd Total Sq. yards

Total Conc. Gals.

1st. Coat 0.12 10000 1200

2nd. Coat 0.08 10000 800

Total for 2 coat 0.20 10000 2000

SEALCOATING APPLICATION

29

JOB CALCULATIONSMixture From Conc. Sealer

Application Mix Design Total Mixed Sealer

Conc. Sealer Water @ 30% Sand, 3lb. Mixture Factor

Gal Gal Lbs. (Gal) Gals. MSF

1st. Coat 1200 360 3600 (166) 1726 1.44

2nd. Coat 800 240 2300 (111) 1151 1.44

Total for 2 coat 2000 600 6000 (277) 2877 1.44

Mixed Sealer Factor (MSF)Ratio between mixture and the conc. Sealer

Conc. Coverage Rates Shall be multiplied with MSF

SEALCOATING APPLICATION

30

SEALCOATING APPLICATIONSequence, Steps, Procedure & Precautions

STEPS IN APPLICATION1. PAVEMENT PREPARATION

1.1. CLEAN REMOVE GRASS, WEEDS, AND DIRTUSING BRUSH, BROOM, BLOWER, POWER WASHING.

1.2 REPAIR CRACK FILL WITH:- COLD POUR FOR CRACKS UPTO ½ INCH WIDE- HOT POUR CRACK FILLER FOR LARGER CRACKS.PATCH & OVERLAY THE PROBLEM AREA- BADLY

ALLIGATORED, BASE PROBLEMS. ALLOW THE FRESH ASPAHLT TO CURE.1.2 OIL SPOTS SCRAPE HEAVY BUILD UPS. WASH WITH DETERGENT, AND

SEAL WITH OIL SPOT PROMERS. SOFT AREAS-PATCH.

Sealcoating will not fix the pavement problems. Pavement must be sound, free of defects prior to sealcoating.

SEALCOATINGS ARE SURFACE PROTECTIVE TREATMENTS, NOT REPAIR PRODUCTS. 31

SEALCOATING APPLICATIONSequence, Steps, Procedure & Precautions

STEPS IN APPLICATION2. SEALCOATING APPLICATION

2.1. MATERIAL PREPARATION FOR THE JOB: USE SUGEGSTED MATERAILS AND MIX

DESIGN FOR THE JOB. HAVE THE RIGHT MIXING EQUIPMENT WITH

MECHANICAL AGITATION KEEP MATERIAL AGIATETD DUING APPLICATION MAKE SURE THAT SAND STAYS IN SUSPENSION. MAKE SURE APPLICATION EQUIPMENT

(PUMPS, NOZZLES, TIPS, WAND, ETC. ARE IN GOOD WORKING CONDITION.

32

SEALCOATING APPLICATIONSequence, Steps, Procedure & Precautions

STEPS IN APPLICATION2. SEALCOATING APPLICATION

2.2. APPLICATION TRIM THE EDGES WITH A SQUEEGEE OR A BRUSH APPLY THE SEALER ON A SAMLL PRE-MEASURED

AREA TO SET CORRECT APPLICATION RATE. APPLY THE SEALER IN LARGER AREAS USING A

SUITABLE METHOD- SPRAY, BURSH OR SQUEEGEE. KEEP MATERIAL AGIATETD DUING APPLICATION

MAKE SURE THAT SAND STAYS IN SUSPENSION. APPLY THE NO. OF REQUREID NUMBER OF COATS IN MULTIPLE COAT APPLICATION-ALLOW EACH COAT

TO DRY SIFFICIENTLY BEFORE APPLYING THE FOLLOWING COAT

ALLOW TO THE FINAL COAT TO DRY FOR A MIN.OF 24 HRS., BEFORE OPENIG THE LOT FOR TRAIIFC.

33

SEALER APPLICATION MEHODS BRUSH SQUEEGEE OR SPRAY???

Comparison aspects SPRAY SQUEEGEE

Investment Considerable Economical to considerable.

Cost Controls. Material usage.

Controllable , Better Control of Material Usage

Un-controllable, material usage will depend upon the surface roughness and age.

Skill Level Highly Skilled work. Thorough training required

Moderate skill. Not much training is needed.

Size of Projects Medium to large Small, medium, large

Appearance of the finished job

Excellent, UniformTextured appearance.

Fair-to good, May appear streaky

Safety in handling Good, Material is under pressure, may accidently discharge due to equipment malfunction.

V. Safe

Application under windy conditions

Risky- Stay away from buildings.

No problem34

SEALER APPLICATION MEHODS BRUSH SQUEEGEE OR SPRAY???

Comparison aspects SPRAY SQUEEGEEInvestment Considerable EconomicalUniformity of the coating application

Uniform on the surface as well as in the profile of the pavement.

Thick in the profile and wipes the top of the aggregates in the pavement.

Conclusions Mechanical application for both types are well accepted and have yielded years of dependable performance. le

The main drawback is the cost control of the material usage

Best compromise Brush application of the first coat and spray application of the second coat.

35

SEALCOATING PRINCIPLES for CONTRACTORS

PROTECTION & PRESERVATION OF ASPHALT SURFACES

part iII-special notes(Do & DON’TS, TROUBLESHOOTING)

PRESENTED BY Girish C. Dubey

President, STAR, INC.

36

SEALCOATINGS- DO & DON’Ts

DO DO NOT

General 1. Sell for intended purpose Oversell. Sealcoating will not repair deteriorated pavements.

2. Follow manufactures recommendations for Application, safety in handling, compliance to regulations, and personal safety.

FLY BY THE SEAT OF YOUR PANTS. -Ignore instructions and safety instructions.-Indulge in reckless practices.

Inspection & Bidding

Walk through, Measure, Pavement Prep steps. Calculate, Material, Labor, overheads (direct and general), profits.

Depend on sketches, GPS maps, Property owners estimates and cost calculation for previous jobs.

37

SEALCOATINGS- DO & DON’Ts

DO DO NOT

TechnicalDetails

1. Sealer shall meet appl. Specs.2. Mix design- Follow

recommendations a. Water- clean and potable b. Sand-Clean, Quartz 50-70 mesh. c. Additives- As recommended.

3. Mixing shall be thorough

1. Miscalculate the mix design. Sealer is 100 base.

a. Sand- no used foundry or sand blasting spent sand

b. Mix additives from diff. suppliers. Always seek sealer suppliers approval.

2. Incomplete/improper mixing shall result in poor performance.

38

SEALCOATINGS- DO & DON’Ts

DO DO NOT

APPLICATION Follow manufacturers recommendation for ;a. Pavement preparation.b. Selection of application tools,

brush, squeegee, spray , etc.c. No. of coats and coverage rates.d. Ambient application conditions

and drying times

a. Take Short cuts in pavement preparation.b. Over or under apply.c. Open the lot too soon. Have a disclaimer signed by the property owner if they want the lot opened sooner. d. Let the wash water go into storm sewer. e. Do not apply if there is any chance that rain will wash away the sealer into the bodies of water.

Do a professional Job. Be a professional

Leave dirt and debris, etc. on the job after finishing.DO NOT SHORTCHANGE YOUR CUSTOMER

39

TROUBLE SHOOTINGProblems, Causes & Remedies

Problems Causes Remedies

Pre-mature wear,

Un-even wear,

Sand knocked off

1. Thin coat application2. Too much water in the mix.3. Too much sand and large size, sand roll out

that will abrade the sealcoating.4. Inadequate mixing of components in the

sealer5. Improper cure conditions, too cold or

freezing overnight temps. Get weather report for analysis.

6. Dirty, over-oxidized pavement.7. Inadequate drying and cure, job was

rushed and lot opened too soon. 8. Inferior Product-Quality Issues.

1. Right coverage rate2.Right Mix design3.Mix thoroughly. 4. Prepare the pavement right.5. Do not apply under cold, high humid or foggy conditions.5. Select the right products. Ask for performance reports from your manufacturer.

40

TROUBLE SHOOTINGProblems, Causes & Remedies

Problems Causes RemediesUn-even color & appearance problems

1. Cure under improper ambient conditions.2. Curing under sun and shade. 3. Inadequate mixing of the components in the mix

design.4. Changing mix designs for the same project.5. No or very little sand in the mix. Also sand un-

evenly suspended in the mix. 6. Streaky appearance- sand falling in the

windrows. Poor sand suspension in the mix.7. Uneven rate of application, machine mal-

function or in-experienced applicator. 8. Inconsistent pavement condition (smooth,

rough, patchy, oxidized)9. Changing direction of application, uneven brush

or squeegee patterns.10. Landscape irrigation run off.

1.Must apply under the right cure conditions.2. Allow more cure time, the color will blend in.3. Use the same mix design for the entire project.4. Check the accuracy of the appl. Rate on a test area.5.Follow uniform windrows.6.Make property owner aware about inconsistent pavement.

41

TROUBLE SHOOTINGProblems, Causes & Remedies

Problems Causes RemediesAdhesion

failure 1. Pavement not sufficiently cured

(surface oily). 2. Pavement too old and oxidized,

not properly cleaned and primed

3. Oil Spots not properly primed.4. Dirty pavement Excessive oil, grease, etc.5. Polished aggregates6. Excessive sand loads (>8lb./gal) 7. Applied under cold or o/n freezing conditions.

1. Test the pavement to make sure the pavement is aged (cured enough)2. Clean and prime with oil spot sealer or specialty coatings. 3. cure conditions must be right.

42

SEALCOATING PRINCIPLES for CONTRACTORS

PROTECTION & PRESERVATION OF ASPHALT SURFACES

part Iv- FREQUENTLY ASKED QUESTIONS

PRESENTED BY Girish C. Dubey

President, STAR, INC.

43

FREQUENTLY ASKED QUESTIONS:

Sealer Performance Q.1. Why are two (2) thin coats better than one thick coat? A.1. Sealer applied in two coats dries and cures much better than one thick coat application. Remember sealers are water-based coatings, which cure through the process of water release (evaporation). A thin coat will release water much faster than a thick coat. If applied in one thick coat, sealer will have a tendency to hold water and stay soft for a longer period of time, possibly causing tracking. Q.2. Why did the sealer fail or peel? A.2. Peeling is caused by sealer not bonding to oil spots or any other surface contaminants like dirt, grease, etc. or oxidized pavements. All the areas shall be thoroughly cleaned; oil spots shall be primed with specialty primers. Oxidized pavements shall be treated with a diluted coat of sealer or a specialty coating or a diluted asphalt emulsion. Q.3. What causes white streaks in the sealer? A.3. Streaks in the cured sealer film are possibly caused by incomplete mixing of clays and fillers in the manufacturing process of the sealer. The Sealcoating manufacturer should be able to rectify this problem.

44

FREQUENTLY ASKED QUESTIONS:

Q.4. Why does the sealer dry gray? A.4. Due to less than ideal conditions:

High Humidity, Cooler temperatures , Shade.Mostly it is temporary, it will cure to a darker color.

Remedy- Use of fast drying additives- helps sealer dry faster and at a uniform rate.

Q.5. Why does the sealer wear out faster in traffic lanes, entrances and exits?

A.5. More traffic More Wear.

Excessive wear- Indication of adhesion problem to smooth/polished aggregates. Such

Remedy- Use of specialty primers to penetrate the smooth polished aggregates and allow the sealcoating to bond, effectively. Prime faster traffic lanes, exits and entrances.

45

FREQUENTLY ASKED QUESTIONS

APPLICATION Q.6. How soon I can sealcoat a freshly laid asphalt pavement? A.6. As soon as the surface rids of light oils through oxidation.

Allow 90 days or more, depending upon locations. Perform a simple test called "water break test". - Spread some water on the surface. If the water sheets out without beading, you are ready to sealcoat.Remedy- For fresh patches, etc. prime with a specialty primer.

Q.7. While spraying how do I know if I am applying at the recommended coverage rate e.g. 0.12-gallon/sq. yard?

A.7. 1. Select 10’ x 10’ area of the pavement and place a

3"x 6" metal plate in the center. 2. Spray Sealcoating in this area.3. Lift the metal plate before the Sealcoating dries. 4. Use the film thickness gauge to determine the wet film thickness. The reading will be in mils (1/1000 of an inch). Compare this reading with the desired film thickness for 0.12 gallon/ sq. yard coverage which is 21 mils.

Q.9. What type of striping paints should be used and how soon can the lot be striped? A.9. Water based traffic paints are preferred. Allow the sealer to dry and cure at least 24 hr. after the application of the final coat of the sealer, prior to striping. If applied sooner, traffic markings may turn brown and blotchy. Most of the waterborne traffic paints contain some fast evaporating solvents. These solvents extract lighter fractions from the binder (coal tar or asphalt) portion of the partially cured film of the sealer. The extract floats to the surface of the paint film, thus rendering it brown and blotchy.

46

FREQUENTLY ASKED QUESTIONS

APPLICATION

Q. 8. What type of striping paints should be used andhow soon can the lot be striped?

A. 8. Water based Acrylic Traffic Paints are preferred.

Alkyd (oil) based paints are also used.

a. Allow the sealer to dry and cure at least 24 hr. after the application of the final coat of the sealer, prior to striping.

b. If applied sooner, traffic markings may turn brown and blotchy.

Note: -Most of the water borne traffic paints contain some fast evaporating solvents.

-These solvents extract lighter fractions from the binder (coal tar or asphalt) portion of the partially cured film of the sealer. -The extract floats to the surface of the paint film, thus rendering it brown and blotchy.

.

47

FREQUENTLY ASKED QUESTIONS

Mix Designs- Sand/Aggregate

Q. 9. Can you explain sieve size, % retained, % passing, etc.? A. 9 a. Sieve sizes- Sand/aggregates must fall within a range

of particle sizes, neither too coarse nor too fine. The sand is sifted through a set of screens with varying mesh sizes (openings in the screen). b. Percent retained means how much of 100 grams of sand was retained on the screen and, c . Percent passing is how much passed through the screen.

Use your manufacturers recommended grades. Q.10. Why should we use sand? A.10. a. Traction/ skid resistance,

Note- Be aware of the liability issues before making claims sealcoating will improve the skid resistance or make a surface slip resistant.

b. Toughness of the cured coating film, c. A uniform textured, non-glare surface. D. It fills minor hairline cracks. Do not claim that it will fill larger cracks. 48

FREQUENTLY ASKED QUESTIONS

Mix Designs-Additives

Q.11. Why use latex additives? A.11. The use of latex additives is very common. There are many latex additives to impart all types of performance advantages. For example;

a. Rubberizing additives improve flexibility, durability, toughness, etc.

b. Faster drying additives help sealers dry fast. c. Water repellent additives improve water resistance of the cured sealer d. Thickening additives build the viscosity of sealcoatings diluted with large amounts of water. Suspend large amount of sand.

Follow the manufacturer’s recommendations.

.

49

FREQUENTLY ASKED QUESTIONS

Mix Designs-Additives

Q.12. What happens when you use different additives (different suppliers) in the same tank? Why did the viscosity go haywire? A. 12. The viscosity went haywire because the additives were not compatible with each other. Do not mix different additives and stick to manufacturer recommendations. Also the manufacturers’ warranty may be void if you use other additives. Additionally, use the additive recommended by your sealcoat manufacturer. Additive made by someone else may not be compatible with the sealer made by another manufacturer. Q.13. Why apply two coats, when one coat looks good enough? A. 13. Appearance is only part of the benefits. The sole purpose of sealcoating is to protect and preserve the asphalt. One coat may not last even half as two coats. It will provide only half (or less) of the protection and will wear out, prematurely. You will have to sealcoat more frequently if you used only one coat.

.

50

FREQUENTLY ASKED QUESTIONS

Mix Designs Q.14. How much water can I use? A.14. Follow the manufacturers’ recommendations. Normally 25-30 gallons per 100 gallons of concentrated sealer are recommended. Higher percentages are recommended for mix designs that use additives and larger amounts of sand.

Q.15. What is the deal with specifications using excessive amounts of sand, e.g. 18 lb. of sand in one of the FAA Specifications? A.15. Those are special sand slurry specifications and not used commonly for sealcoating specifications. The industry recommends a maximum of 8 lb. of sand per gallon. Very high sand loading (18 lb. for example) will result in a coating that will be poor in flexibility, adhesion and chemical resistance. Q. 16. Where can I get straight, objective answers?A. 16. From your supplier.

Editor of the “Pavement” magazine.

.

51

RIGHT??

Thanks for your time & attention and participation.

52