Asphalt Test

ASPHALT TECHNOLOGY

IMPORTANCE OF ASPHALT

ASPHALT

A dark brown to black cementitious material, solid to semi-solid in c o n s i s t e n c y i n w h i c h t h e predominating constituents are called bitumen, which are found in nature, or as residue in petroleum refining.

Properties of Asphalt •  Physical

a. Consistency – ranges from a very thin liquid to a stiff semi- solid state.

b. Temperature Susceptibility – thermoplastic substance.

c. Adhesion – ability to stick to the agg.

d. Cohesion – ability to hold the agg. particle firmly

e. Durability– resistance of asphalt to changes in properties due to weathering or aging.

f. Hardening – asphalt hardens when heated to higher temperature.

Chemical Composition of Asphalt

2. Maltenes

a. Resin – provides stickiness (adhesiveness)

b. Oil – influences viscosity of asphalt & imparts softness

1. Asphaltenes

a. Gives Color Black

b. Hardness

Uses of Asphalt 1. Binder

2. Water proofing material

3. Joint and crack filler

4. Roofing

5. Prime Coat

6. Tack Coat

7. Sealing (PCCP)

8. Pipe Coating

Kinds of Asphalt

1. Natural Asphalt

a. Rock Asphalt

b. Lake Asphalt or Pure Deposit

2. Manufactured Asphalt

a. Asphalt Cement – Penetration grade 40 to 300

b. Blown Asphalt – Penetration grade 0 to 30

c. Liquid Asphalt – Cutback asphalt & emulsified asphalt

Refining Process of Petroleum Asphalt

Asphalt is a natural component of petroleum crude oil taken from the hundred of thousand of oil wells throughout the world today

CLASSIFICATION OF PAVING ASPHALT

A.  Asphalt Cement or Hot Asphalt, 99% (bitumen) pure, 1% impurities

- Penetration Grades:

40-50, 60-70, 85-100, 120-150, 200-300

Characteristics

1. Solid to semi-solid in consistency

2. Odorless

3. Black in Color


B. Liquid Asphalt

Cutback Asphalt – blend of Asphalt Cement + Solvent Classification:

1. Slow Curing (SC) – Asphalt Cement + Non-volatile or slowly volatile roads oils

- liquid at room temperature - SC – 70 - SC – 250 - SC – 800 - SC – 3000


B. Liquid Asphalt Cutback Asphalt – blend of Asphalt Cement + Solvent Classification: 2. Medium Curing (MC) – Asphalt Cement + Kerosene

- characteristic smell of kerosene - liquid at room temperature - MC – 30 - MC – 70 - MC – 250 - MC – 800 - MC – 3000


B. Liquid Asphalt Cutback Asphalt – blend of Asphalt Cement + Solvent Classification: 3. Rapid Curing (RC) – Asphalt Cement + Gasoline

- characteristic smell of gasoline - liquid at room temperature - RC – 70 - RC – 250 - RC – 800 - RC – 3000


B. Liquid Asphalt

Emulsified Asphalt – blend of Asphalt Cement + Water + Emulsifier - usually 60% asphalt and 40% water

Characteristics:

- liquid at room temperature - Pungent Odor - Chocolate brown in color


Emulsified Asphalt

á Anionic Emulsified Asphalt

Classifications:

- Rapid Setting (RS-1, RS-2) - Medium Setting (MS-1, MS-2) - Slow Setting (SS-1, SS-1h)

á Anionic Emulsified Asphalt

- Negatively Charged globules


Emulsified Asphalt

Classifications:

- Rapid Setting (CRS-1, CRS-2) - Medium Setting (CMS-1, CMS-2) - Slow Setting (CSS-1, CSS-1h)

á Cationic Emulsified Asphalt - Positively Charged globules

á Asphalt/Concrete Joint Sealer/Filler

- Hot poured elastic type - Preformed/Pre-molded

Asphalt Cement QUALITY/PHYSICAL TESTS:

1. Specific Gravity

2. Penetration

3. Loss on Heating

4. Penetration after Loss

5. Spot test

6. Flash Point

7. Ductility

8. Solubility

Emulsified Asphalt QUALITY/PHYSICAL TESTS:

1. Viscosity

2. Distillation

3. Cement Mixing

4. Sieve Test

5. Storage Stability

6. Test on Residue

a. Penetration

b. Ductility

c. Stability

Cutback Asphalt QUALITY/PHYSICAL TESTS:

1. Viscosity

2. Flash Point

3. Distillation

4. Test on Residue

a. Penetration

b. Ductility

c. Solubility

d. Spot test

QUALITY/PHYSICAL TEST OF ASPHALT CEMENT

a. Weigh pycnometer empty

1. SPECIFIC GRAVITY – indicates the uniformity of the product/supply

APPARATUS: Fisher pycnometer, heating device, balance


Fill the pycnometer with water



b. Then weigh the pycnometer



Pour the heated asphalt sample into the pycnometer to about three fourths of its capacity.



c. Cool the pycnometer and sample, then weigh with the cover.



Fill the pycnometer with sample plus water



d. Then weigh


Formula: Specific Gravity = (c - a) ÷ [(b - a) - (d - c)]


a. Pour heated sample in MC can then cool

2. PENETRATION – determines the hardness of asphalt Apparatus: Penetrometer, timer, mc can, water bath, thermometer


b. Immerse in a water bath for 1-1/2 to 2 hours at a temperature of 250C

2. PENETRATION – determines the hardness of asphalt


c. Immediately after the curing period, perform the test. Take at least three (3) penetration trials/readings, report the penetration

as the average of the three

2. PENETRATION – determines the hardness of asphalt


a. Weigh MC cans empty (take at least two trials)

3. LOSS ON HEATING – determines the rate of loss of volatile oil on asphalt when heated and the change in penetration caused by excessive heating

Apparatus: Oven with revolving shelf, mc cans, balance


b. Pour 50 grams each of the heated sample in the two MC cans.



c. Cool and weigh



d. Place the samples in the rotating shelf of the oven maintained at a temperature of 1630C for five (5) hours

3. LOSS ON HEATING – determines the weigh of loss of volatile oil on asphalt when heated and the change in penetration caused by excessive heating


d. Cool and weigh


Computation/Formula:

% loss = weight loss after heating x 100 mass of original sample


a. Weigh 2 grams of the heated sample in a florence flask

4. SPOT TEST – determines if asphalt is over heated during production

Apparatus: Florence flask, filter paper, pipette or buret, balance, 25% xylene-heptane solution


b. Pour 10 ml of the solvent (25 % xylene – heptane solution) in the florence flask



c. Swirl the flask to dissolve the sample with the aid of a boiling water bath. The process is repeated until complete dispersion has taken place. Cool the asphalt solvent mixture to room temperature for 30 min. then warm again for 15 min in a water bath at 320C



c. A drop of warm mixture shall be placed on the filter paper. Examine the drop after 5 min. if the drop forms a brown or yellowish brown circular stain, with a darker solid or annular nucleus in the center, the tests shall be reported as positive. But if the drop forms a uniformly brown circular stain, repeat placing the drop on another filter paper the following day. And if it forms the same uniformly brown circular stain, then report it as negative, but if the drop forms a solid or annular nucleus report it as positive.



a. Fill the cup with the heated sample

5. FLASH POINT – indicates the safe heating temperature of asphalt

Apparatus: Cleveland Open Cup, thermometer


b. Place the cup in the heater. Apply heat until the temperature of the sample reaches at least 280C below the flash point



c. Pass the test flame across the center of the cup. Record as the observed flash point the temp. when a flash appears at any point on the surface of the sample.


Test flame


1. Ductility machine

6. DUCTILITY – measures the ability of the asphalt to stretch without breaking

Equipment/Apparatus:


2. Ductility molds/base plate (brass plate)



a. Pour the heated sample into the prepared mold until it is level full


Procedure:


b. Cool the sample and the mold for at least 30 mins. and then place the mold in the water bath maintained at a temperature of 250C for 85 to 95 mins.



c. Remove the briquette from the plate, detach the side pieces and attach the clips to the pins/hooks of the testing machine with a bath of the machine maintained at 250C. Pull the clips apart at a rate of 5 cm/min. Measure and record the distance through which the clips have been pulled to produce rupture


JOB MIX FORMULA

The job-mix formula is the primary quality control mechanism for the production of asphalt mixture, mixture, which shall conform with following ranges of tolerance:

Passing No. 4 and larger sieves +/-7% Passing No. 8 to No. 100 sieves +/-4% Passing No. 200 sieves +/-2% Bituminous material +/-0.4% Temperature of mixture +/-10°C a. mixture shall have a minimum dry comprehensive strength of 1.4Mpa (200psi) b. The mixture shall have a mass percent air voids with the range of 3 to 5. c. The mixture shall have an index of retained strength of nor less than 70%

The Marshall Stability Method is the most commonly

used method in the design and evaluation of bituminous

concrete mixes.

QUALITY CONTROL TEST FOR ASPHALT MIX

A. The immersion/Compression test determines the index of Retained Strength of the mix. Which is the ratio of wet to dry stability of the mix (compressive strength).

QUALITY CONTROL TEST FOR ASPHALT MIX

B.  Extraction and Grading tests determines asphalt content and practice size

distribution of coarse and fine aggregates, respectively.

C. The laboratory density test determines the degree of compaction.

Gradation Ranges – Hot Plant Mix Bituminous Pavements (Mass percent passing square sieves, AASHTO T 11 and T 27)

Sieve

Designation, mm

A

B

C

D

E

F

G

37.5 (1 ½ inch.) 100 - - - - - - 25 (1 inch.) 95-100 100 100 - - - - 19 (3/4 inch) 75-95 95-100 95-100 100 - 100 - 12.5 (1/2 inch.) 68-86 68-86 95-100 100 - 100 9.5 (3/8 inch.) 54-75 56-78 56-78 74-92 95-100 - 95-100

4.75 (No.4) 36-58 36-60 36-60 48-70 75-90 45-85 30-50 2.36 (No. 8) 25-45 27-47 27-47 33-53 62-82 33-53 5-15 1.18 (No. 16) - 18-37 18-37 22-40 38-58 - - 0.600 (No. 30) 11-28 11-28 13-28 15-30 22-42 - - 0.300 (No. 50) - 6-20 9-20 10-20 11-28 10-20 - 0.075 (No. 200) 0-8 0-8 4-8 4-9 2-10 3-8 2-5

ITEM 310 – BITUMINOUS CONCRETE SUREFACE COURSE 1995 STANDARD SPECIFICATION, GRADING E

JOB-MIXING FORMULA

ITEM 310-B I.  Gradation Sieve Sizes

Inch mm Job Mix

Gradation Job Mix

Specifications Min. Max.

General Specifications

Min. Max.

1 25.4 100 100 100 100 100

¾ 19 99 95 100 95 100

½ 12.5 81 74 86 68 86

3/8 9.5 68 61 75 56 78

#4 4.75 50 43 57 38 60

#8 2.36 38 34 42 27 47

#16 1.18 28 24 32 18 37

#30 0.600 18 14 22 11 28

#50 0.300 11 7 15 6 20

#200 0.075 5 3 7 0 8


JOB-MIXING FORMULA

II. Asphalt Content a. Asphalt Cement Penetration 60/70 b. % be Weight of Aggregates 5.52 c. % Weight of Mix 5.23

III. Filler

Fly Ash IV.  Additives

Hydrated Lime V. Temperature

Asphalt Cement 135oC - 140oC Aggregates 150oC - 160oC Mixing 145oC - 175oC Compaction 107oC minimum


JOB-MIXING FORMULA

B. BLENDING COMPOSITION OF AGGREGATES

Bin No. 1 -- Sand - 83.5% Bin No. 2 -- 3/8” Agg. - 16.0% Filler Bin -- Cement - 0.5%


JOB-MIXING FORMULA

C. GRADATION OF AGGREGATES Sieve Designation

Result

General Specification

Job-Mix

Specification (inch) (mm)

½” (12.5) 100 100 100

3/8” (9.5) 89 95-100 95-100

No.4 (4.75) 82 75-90 75-89

No.8 (2.36) 64 62-82 62-68

No.16 (1.18) 40 38-58 38-44

No.30 (0.60) 26 22-42 22-30

No.50 (0.30) 15 11-28 11-19

No.200 (0.075) 5 2-10 3-7


JOB-MIXING FORMULA

D. SPECIFIC GRAVITY Specific Gravity of Asphalt Cement = 1.03 Effective Sp. Gr. of Aggregates = 2.79


JOB-MIXING FORMULA

E. TEST ITEM

Items

Result Specifications

Min. Max. 1.  Optimum Asphalt Content (%) by. wt. of

mix 5.50 5.10 5.90

2. Stability (lbf) 2700 1800 + 3. Number of blows each face 75 4. Flow (0.01 in.) 13 8 16 5. Air Voids 3.75 3 3 6. Compacted Pavement Density (%) 90 90 + 7. Mixing Temperature, °C 150 130 165 8. Compaction Temperature, °C 130 120 9. Laying Temperature, °C 130 120

MARSHALL TEST Procedure: 1. Segregate the aggregates in different size according to their grading. 2. Batch wt. 3. Heating of aggregates.

A. Heating temperature of Aggregates - 177°C-191°C B. Heating temperature of Asphalt - 121°C-138°C

4. Mix – mixing temperature - 163°C 5. Mold the specimens - Compaction Temp. 124°C

Mold it by compaction 25 times with a heated Spatula fifteen times around & remaining with at random over the mixture. The remaining half of the mixture similar spading action repeated. No. of blows depends on traffic you are designing.

MARSHALL TEST

6. The cool the specimen – extrude the mold after 24 hours. 7. Measure the specimen at four (4) angles and get the average. 8. Get Gmb (Bulk Specific Gravity) 9. Water Cure – 30-40 minutes at a temperature of 60°C. 10. Take the stability test by means of Marshall apparatus and flow test.

Table 5.2 MARSHALL MIX DESIGN CRITERIA

Light Traffic Surface and Base

Medium Traffic Surface & Base

Heavy Traffic Surface & Base

Marshall Method Mix Criteria 1 Min Max Min Max Min Max

Compaction, number of blows each end of specimen

35 50 75

Stability, N (lb.)

3336 (750)

- 5338 (1200)

- 8006 (1800)

-

Flow, 0.25 mm (0.01 in.) 8 18 8 16 8 14

Percent Air Voids 3 5 3 5 3 5

Percent Voids in Mineral Aggregate (VMA)

See Table 5.3

Percent Voids Filled With Asphalt (VFA)

70 80 65 78 65 75

Common Distresses for Asphalt Concrete Pavements

QUALITY/PHYSICAL TEST OF CUTBACK ASPHALT

a.  Weigh the pycnometer empty. b.  Weigh the pycnometer with water c.  Weigh the pycnometer filled with sample

1. SPECIFIC GRAVITY

c - a Specific Gravity = ----------------- b - a

Apparatus: same as in asphalt cement


b. Mix the sample thoroughly and measure a 20 ml representative sample

1. KINEMATIC VISCOSITY – measures the resistance of the asphalt to flow

a. Mount the viscometer in the bath maintained at 600C


Viscometer, water bath, thermometer,


c. Introduce sample through the big tube into the cross arm until the leading edge stands within 0.5ml of the fill mark



d. Allow the charged viscometer to remain in the bath for around ten(10) minutes to attain temperature equilibrium.



e. Start the flow of asphalt in the viscometer by applying pressure to the big tube or slight vacuum to the small tube, until gravity flow is initiated.



f. Record the time required for the leading edge of the meniscus to pass from the first timing mark to the second.


Viscosity @ 600C, Cst = time in seconds x Calibration Constant of viscometer, Centistokes / Second


a. Weigh in a 500 ml flask the mass of a 200 ml of the sample calculated based from the specific gravity of the material

2. DISTILLATION – determines the asphalt content of liquid asphalt


Distilling flask, condenser, adapter, shield, shield and flask support, heat source (bunsen burner), graduated cylinder, thermometer, balance


b. Place the flask in the shield supported by wire gauze in a ring/tripod


c. Assemble the distillation apparatus


d. Pass cold water through the condenser jacket. Apply heat to the distilling flask


e. Record the volume of distillate starting from 225°C, 260° C , 3150C


f. When the temperature reaches 3600C, extinguish the flame & r e m o v e t h e f l a s k a n d thermometer. Immediately pour the contents of the flask in the residue container


g. Record the total volume of distillate collected at 3600C

Residue, % by volume vol.of orig sample-total vol.of distillatex100

vol of original sample

TEST ON RESIDUE:

1.  Penetration

2.  Ductility

3.  Solubility

4.  Spot


a. Pour sample into the glass container

3. FLASH POINT – same significance as in asphalt cement The procedure is similar to asphalt cement, the difference is just in

the method of heating the sample, since the flash point of cutback is lower than asphalt cement: heating of sample is through a water bath, not direct heating.

b. Place the glass container in the water bath and attached the thermometer to the heater

Apparatus: Tag open cup, thermometer


c. Start heating the water bath with the glass container filled with sample. Pass a test flame across the center of the cup. Record as the observed flash point the temperature reading on the thermometer when a flash appears at any point on the surface of the sample.

3. FLASH POINT

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT

a. Stir the sample thoroughly and pour into a 100 ml. flask. Place the flask in the water bath at 250C for 30 mins.

1. VISCOSITY SAYBOLT

b. Place the cork stopper in position and pour the sample into the viscometer through the No. 20 sieve


Saybolt Viscometer and bath, 60 cc receiving flask, #100 sieve, thermometer


c. Place a 60 cc receiving flask under the outlet tube. Snap the cork at the same time starting the timer

1. VISCOSITY, SAYBOLT

d. Stop the timer the moment the lower meniscus on the flask reaches the 60 cc mark. Record the effluent time in second.


a. Record the mass of the sieve + pan

2. SIEVE TEST – determines the presence of larger globules of asphalt in the emulsion

b. Weigh 1000 gms of the emulsified asphalt into a suitable container


Sieve #20, pan, sodium oleate solution/distilled water, balance


c. Pour the sample through sieve No. 20.


d. Wash the container and residue until the washwater is clear


e. Place the pan under the sieve and oven dry for two hours at 1100C


f. Cool and weigh

Weight Residue Sample Retained,% = ----------------------------X 100 1000


a. Dilute the emulsion with distilled water to a residue of 55%, as determined by the distillation test

3. CEMENT MIXING – determines the resistance of the emulsion to breakdown on the job. It indicates the rate at which the emulsion will break when mixed with aggregates

Example: % residue = 58 55 ÷ 58 x 100 = 95 ml of sample

For 100 ml solution: 100 - 95 = 5 ml of water for dilution

Apparatus/Materials: Sieves(#80 &14), dish(watch glass), stirring rod, graduated cylinder, balance, cement, oven


c. Sieve 50 grams of portland cement through No. 80 sieve


d. Measure a 100 ml solution with the computed proportion


e. Add the diluted solution to the 50 grams cement


f. Stir the mixture at once with the steel rod using a circular motion at a rate of 60 rpm


g. At the end of the one minute mixing period, add 150 ml of distilled water and continue the stirring for 3 mins.


h. Weigh the No. 14 sieve with a pan or watch glass


i. Pour the mixture through a weighed No. 14 sieve. Use repeated washings to completely remove material from the mixing bowl


j. Pour the washings over the sieve

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT 3. CEMENT MIXING – determines the resistance of the emulsion

to breakdown on the job. It indicates the rate at which the emulsion will break when mixed with aggregates

l. Place the sieve in the weighed watch glass/shallow pan and oven dry at 1630C until constant weight

k. Rinse the sieve using distilled w a t e r , h e l d a t a h e i g h t approximately 6 inches until the water is clear.

Amount of Residue Cement Mixing, % = -------------------------------- x 100 100

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT 4. STORAGE STABILITY – detect the tendency of the asphalt

globules in the emulsion to settle during storage -- measures the permanence of the

dispersion as related to time

a. Place a 500 ml sample to a glass cylinder

Apparatus/Materials: two(2) 500 ml cylinders, glass pipet, balance, beakers(1000 ml cap), oven


4. STORAGE STABILITY – detect the tendency of the asphalt globules in the emulsion to settle during storage

-- measures the permanence of the dispersion as related to time

b. Stopper the cylinder and allow to stand undisturbed at laboratory air temperature for 24 hours.

c. Remove approximately 55 ml from the top of the emulsion by means of a pipet

d. Weigh 50 gms into the previously weighed beaker with a 7 inches glass rod inside and a watch glass

e. Take the total weight of the beaker

f. Siphon off the next 390 ml from the cylinder without any disturbance to the bottom sample

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT 4. STORAGE STABILITY – detect the tendency of the asphalt

globules in the emulsion to settle during storage

g. Mix the emulsion remaining in the cylinder and weigh 50 grams into the previously weighed beaker with glass rod and watch glass

h. Take the total weight of the beaker

i. Heat the two beakers containing the top and bottom sample in a stove for an hour to remove water and then transfer in an oven at a temperature of 1630C for an hour. Cool and weigh

j. The numerical difference in the asphalt contents of the top and bottom samples represents the storage stability of the emulsion

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT 5. DETERMINATION OF RESIDUE BY EVAPORATION –

determines the asphalt content of liquid asphalt

a. Weigh iron still empty. Pour 200 grams sample in the iron still

Apparatus: Iron still, heat source, thermometer

QUALITY/PHYSICAL TEST OF EMULSIFIED ASPHALT 5. DETERMINATION OF RESIDUE BY EVAPORATION –

determines the asphalt content of liquid asphalt

b. Heat the iron still with sample until all water has evaporated, increase the temperature to 260 °C for 15 minutes. Extinguish the flame and weigh the iron still with residue


5. DETERMINATION OF RESIDUE BY EVAPORATION – determines the asphalt content of liquid asphalt

c. Immediately pour the contents of the iron still into a residue container

d. Calculate the percent residue

Formula: Weight Residue

%, Residue = ------------------------------------ x 100 200

TESTS ON RESIDUE:

1.  Penetration 2.  Ductility 3.  Solubility

Note: Same test procedures as in asphalt cement

BITUMINOUS MIXTURES

Bituminous Mixture

- is a combination of aggregate that are uniformly mixed and coated with bituminous/asphalt materials such as asphalt cement, cutback asphalt or emulsified asphalt

Kinds of Bituminous Mixture

- Bituminous/Asphalt Hot Mix - Bituminous/Asphalt Cold Mix

BITUMINOUS MIXTURES

Composition of Bituminous Mixture

- Bituminous Mix or Hot Mix Aggregate + Asphalt Cement 92% – 95% 5% - 8%

- Bituminous Cold Mix Aggregate + Cutback Asphalt 4.5% - 7% Aggregate + Emulsified Asphalt 6% - 10%

AGGREGATES

a. Coarse Aggregates – retained on No. 8 and larger sieve

b. Fine Aggregates – passing # 8 and retained on # 200

c. Mineral Filler – passing # 200

Three kinds of aggregates for bituminous mix:

Properties of Aggregates

1. Strength 2. Particle Shape 3. Surface Texture 4. Absorption and Specific Gravity 5. Gradation 6. Cleanliness 7. Affinity for asphalt

Properties of Bituminous Mixture 1.  Stability -- ability to resist deformation from imposed

loads * ability to resist shoving and rutting under

traffic

Causes and Effects of Pavement Instability

Causes Effects Excess asphalt in mix Rutting and flushing or bleeding

Excess medium sand in mixture

Tenderness during rolling & for period after construction, difficulty in compacting

Rounded aggregate, little or no crushed surfaces

Rutting

Properties of Bituminous Mixture 2. Durability – ability to resist the detrimental effects of air,

water, temperature and traffic

Causes and effects of lack of durability

Causes Effects Low asphalt content Dryness or raveling High void content through design or lack of compaction

Early hardening of asphalt followed by cracking or disintegration

Water susceptible (hydrophilic) aggregate in mixtures

Asphalt film strips from aggregate leaving an abraded, raveled or mushy pavement

3. Flexibility – ability to bend slightly without cracking and to conform to gradual settlements and

movements of the base and sub grade.

•  Factors affecting Flexibility - High asphalt content - Gradation (open graded)

Properties of Bituminous Mixture

4. Fatigue Resistance – ability to withstand repeated flexing caused by the passage of wheel loads


Causes and effects of Poor Fatigue Resistance

Causes Effects Low asphalt content Fatigue cracking High design voids Early aging of asphalt

followed by fatigue cracking Lack of compaction Early aging of asphalt

followed by fatigue cracking Inadequate pavement thickness

Excessive bending followed by fatigue cracking

5. Skid Resistance – ability to offer resistance to slipping or skidding of the vehicle tires


Causes and effects of Poor Skid Resistance

Causes Effects Excess asphalt Bleeding, low skid

resistance Poorly textured or graded aggregate

Smooth pavement, potential for hydroplaning

Polishing aggregate in mixture

Low skid resistance

6. Workability – ease with which paving mixture maybe placed and compacted


Causes and effects of Workability Problems

Causes Effects Large maximum-size particle Rough surface, difficult to place Excessive coarse aggregate May be hard to compact

A mix temperature that is too low

Uncoated aggregate, not durable,rough surface hard to compact

Too much medium-size sand Mix shoves under roller, remains tender

Low mineral filler content Tender mix, high permeable

High mineral filler content Mix may be dry or gummy hard to handle, not durable

7. Impermeability - prevents the passage of air and water into or through the asphalt pavement.


Causes and effects of Permeability

Causes Effects Low asphalt content Thin asphalt films will cause

early aging and raveling High voids content in design mix

Water and air can easily enter pavement, causing oxidation and disintegration

Inadequate compaction Will result in high voids in pavement, leading to water infiltration and low strength

QUALITY TESTS ON BITUMINOUS MIXES

1. EXTRACTION

2. GRADING/MECHANICAL ANALYSIS OF EXTRACTED AGGREGATES

3. BULK SPECIFIC GRAVITY

4. STABILITY TEST 1. Immersion – Compression test 2. Marshall Stability


1. EXTRACTION – determines the amount of asphalt present in the mix

W1 - W2

% Extraction = ------------------------- x 100 (% Asphalt, by wt. of mix) W1

Where: W1 = weight of sample W2 = weight of sample after extraction

QUALITY TESTS ON BITUMINOUS MIXES 2. GRADING – determines the size distribution of aggregates

whether it is in conformance with the approved design

Sieve Size Wt. Retained Wt. Passing % Passing SPEC’S ¾” ½”

3/8” No. 4 No. 8 No. 16 No. 30 No. 50 No. 200

SPEC’S – refer to the approved job mix formula

QUALITY TESTS ON BITUMINOUS MIXES Example: Job-Mix Formula: READYCON Trading

Sieve Size Cumulative, % Passing ½” 100

3/8” 98 No. 4 82 No. 8 64 No. 16 40 No. 30 26 No. 50 15 No. 200 5

Asphalt Content: % By Mass of Aggregates = 5.8

GRADING: Based on Grading E Item 310 =2004 DPWH SPEC’S

QUALITY TESTS ON BITUMINOUS MIXES Example: Evaluation of a Job-Mix Formula

Ranges of Tolerances: Passing No. 4 and larger Sieves – ± 7% Passing No. 8 to No. 100 Sieves - ± 4% Passing No. 200 Sieve - ± 2% Bituminous Material - ± 0.4%

Sieve Size %, Passing Applying Tolerances

DPWH SPEC’S

Grading Spec’s to

Adopt

½” 100 - 100

3/8” 98 - 95 – 100

No. 4 83 - 75 – 90

No. 8 64 - 62 – 82

No. 16 40 - 38 – 58

No. 30 26 - 22 – 42

No. 50 15 - 11 – 28

No. 200 5 - 2 - 10


3. BULK SPECIFIC GRAVITY - for unit weight determination - used in design computation - used in computation of the degree of compaction: Field Density/Specific Gravity % of compaction = -------------------------------------------- x 100 Laboratory Density/Specific Gravity Spec’s = 95%-97 %


4. STABILITY TEST 4.1 Immersion - Compression test (4 in dia. X 4 in ht) - measurement of the loss of cohesion or adhesion resulting from the action of water

- Dry Stability - Wet Stability

Wet Stability Index of retained strength, % = --------------------- x 100

Dry Stability Spec’s = 70% minimum


4. STABILITY TEST 4.2 Marshall Stability = (4 in dia. X 2-1/2 in ht) - intended for laboratory design and field control of asphalt paving mixtures

Spec’s = refer to Marshall Design Criteria

TESTS ON BITUMINOUS MIXES 1. EXTRACTION

a. Place the sample in a pan and heat/warm until it can be handled or mixed

a. Mix the sample thoroughly, qua r t e r ing f i r s t be fo re sampling

Apparatus/Material: Extraction machine, oven, pans,filter rings,graduated cylinder, solvent(gasoline)


c. Weigh an 850 grams sample d. Place the sample in the bowl


e. Cover the sample with the solvent (gasoline)

f. Weigh the filter ring


g. Fit the filter ring around the edge of the bowl

h. Clamp the cover on the bowl tightly.


i. Place container under the drain to collect the solvent. Start the centrifuge revolving slowly and gradually increase the speed to a maximum of 3600 RPm until the solvent ceases to flow from the drains. Allow the machine to stop, add 200 ml (or more as appropriate for mass of sample) solvent and repeat the procedure at least three (3) times.


j. After the completion of the process transfer the aggregates from the bowl to the pan

k. Dry to constant mass together with the filter ring in an oven at 110 ± 50C. Cool and weigh

TESTS ON BITUMINOUS MIXES

1. EXTRACTION

l. Cool the aggregates and the filter ring and weigh


1. EXTRACTION

Formula:

W1 - (W2 + W3) Asphalt Content, % = ------------------------------- x 100 by mass of dry aggregates W2 + W3

where:

W1 = mass of sample, grams

W2 = mass of extracted aggregates, grams

W3 = increase in mass of filter ring, grams

TESTS ON BITUMINOUS MIXES 2. GRADING/MECHANICAL ANALYSIS OF EXTRACTED

AGGREGATES

a. The test sample (aggregate from extraction test) after being dried & weighed shall be placed in a container & covered with water. Add a sufficient amount of wetting or disbursing agent such as calgon or soap which will promote the separation of fine material

b. The contents of the container shall be agitated vigorously

Apparatus/materials: set of sieves, pans,heating device,balance, disbursing agent


AGGREGATES

c. The wash water shall be poured over a 0.075 mm wash sieve. The operation shall be repeated until the wash water is clear.

d.. The washed aggregates in the container shall be dried to constant mass at a temperature of 110 ± 50C and weighed


AGGREGATES

e. The aggregate shall be sieved over sieves of the various sizes required by the specification covering the mixture, including the 0.075 mm sieve

f.. The weight of material passing each sieve and retained on the next and the amount passing the 0.075 sieve shall be recorded. Compute & report percent (%) passing on each sieve

TESTS ON BITUMINOUS MIXES 3. BULK SPECIFIC GRAVITY

a. Weigh the specimen in air b. Immerse the specimen in water bath at 250C for 3 to 5 minutes. Weigh.

App App Apparatus: specific gravity balance,

TESTS ON BITUMINOUS MIXES 3. BULK SPECIFIC GRAVITY

c. Surface dry the specimen by blotting with a damp towel/cloth. Weigh


3. BULK SPECIFIC GRAVITY

Formula: mass of the dry specimen in air, in grams

Bulk Specific Gravity, Gmb = -----------------------------------------------------------

mass of the saturated surface-dry specimen in air, in grams

- mass of the specimen in water, in grams

TESTS ON BITUMINOUS MIXES 3. IMMERSION COMPRESSION TEST

a. Weigh around 2000 grams of the sample. The weighed sample shall be brought to the molding temperature which is 124 ± 100C

b. Approximately one-half of the heated mixture shall be placed in the molding cylinder & spaded virgously 25 times with 15 of the blows being delivered around the inside of the mold & the remaining 10 at random over the mixture

Apparatus: Testing machine, balance, molds, supports, heating device, oven, water bath, spatula


d. The mixture shall be compressed between the top & bottom plungers under an initial load of 150 psi to set the mixture against the sides of the mold.

c. The sample shall be spaded vigorously 25 times with 15 of the blows being delivered around the inside of the mold & the remaining 10 at random over the mixture. The remaining half of the mixture shall be quickly transferred to to the molding cylinder & the same spading action repeated.


f. The specimen shall be remove from the mold with an ejection device. Make at least four specimen

e. The mixture shall be compressed between the top & bottom plungers under an initial load of 150 psi to set the mixture against the side of the mold. The support bars shall then be removed an the entire molding load of 3000 psi shall be applied for 120 second.


h. Allow the specimen to cool to room temperature for at least two hours then determine the bulk specific gravity

g. After removal from the mold specimen shall be oven cured for 24 hours at 600C


j. Immerse the other two specimens in a water bath with a temperature of 500C for four days

i.  Air dry the two specimens for at least four hours prior to the determination of the dry stability


l. Determine the wet stability k. Transfer the two specimens to another water bath with a temperature of 250C & store them there for two hours

Formula:

Wet Stability

Index of retained strength, % = ----------------------------- x 100

Dry Stability

Asphalt/Concrete Joint Sealer/Filler

1. Hot Poured Elastic Type

TESTS AASHTO M – 173 Specification

a. Safe heating temperature,°C -

b. Pour Point,°C 242 max

c. Flow at 60 °C,mm 5.0 max

d. Penetration at 25°C,150grams, 5 sec 90 max

Asphalt/Concrete Joint Sealer/Filler 2. Preformed:

S P E C I F I C A T I O N S

AASHTO M-33 AASHTO M-153 AASHTO M-213

Compression 689 – 5171 KPa 0.34 – 10.35 Mpa 689 – 5171 Kpa

Recovery - 90% (min.) 70% (min.)

Density - - 304 Kg/m3 (min)

Water Absorption Depends on thickness

AASHTO M-153 - Preformed Sponge Rubber and Cork Expansion Joint fillers for Concrete Paving and Structural Construction

AASHTO M-213 - Preformed Expansion Joint Fillers for Concrete Paving & Structural Construction (Non extruding and Resilient Bituminous Type)

AASHTO M-33 - Preformed Expansion Joint filler for Concrete (Bituminous Type)

MINIMUM TESTING REQUIREMENTS

Kind of Materials Quantity Represented

Minimum Quantity of Sample

I. Asphaltic Material 40 tonnes or 200 drums 4 liters/1 gallon

II. Asphalt Mix 130 tonnes 20 kilograms

III. Asphalt/Concrete Joint Filler/Sealer a. Hot Poured Elastic Type Per shipment/Delivery 400 grams

b. Premolded/Preformed Per shipment/Delivery 1 (400 mm x 400 mm)

One quality test for every . . . . . . . . . .

THANK YOU… GOD BLESS YOU !!!

Documents

Asphalt Test