Lectures of Highway Engineering

University of Babylon College of Engineering Department of Civil Engineering

Lectures of Highway Engineering Forth Stage

01- Cross-Section Elements 02- Earthworks & Mass-Haul Diagram 03- Asphaltic Materials 04- Aggregate 05- Asphalt Paving Mixture 06- Drainage 07- Evaluation of Strength for Subgrade 08- Thickness Design of Flexible Pavement 09- Rigid Pavement 10- The Effect of type and amount of Filler on Asphalt Paving Mix

Prof. Ali Alwash

Asst. Lect. Harith Ajam

Oct-2010

Oct-2010

Lectures of Highway Engineering – Forth Stage

References: 1. Yoder; E. J. and M. W. Witczak, “Principles of Pavement Design”, A Wiley-

Interscience Publication, John Wiley & Sons Inc., U.S.A., 1975. 2. Yaug H. Huang, “Pavement Analysis and Design”, Prentic Hall Inc., U.S.A.,

1993. 3. Paul Croney and David Croney, “The Design and Performance of Road Pavements”, McGraw Hill, U.S.A., 1998. 4. “AASHTO Guide for Design of Pavement Structures 1993”, AASHTO, American Association of State Highway and Transportation Officials, U.S.A., 1993.

5. “A Policy on Geometric Design of Highways and Streets 2001”, AASHTO, American Association of State Highway and Transportation Officials, U.S.A., 2001.

6. Oglesby Clarkson H., “Highway Engineering”, John Wiley & Sons Inc., U.S.A., 1975.

00-2

References

Nov-2009


01- Cross-Section Elements 1. Surface Type: -

Asphalt concrete (flexible pavement).

-

Plan, simply reinforced & continuously reinforced concrete (rigid pavement).

-

Surface treatment Æ for shoulders.

Choice depending on (‫)اﺧﺘﻴﺎر ﻧﻮع اﻟﺴﻄﺢ ﻳﻌﺘﻤﺪ ﻋﻠﻲ‬: a.

Applied stresses (‫)اﻻﺟﻬﺎدات اﻟﻤﺴﻠﻄﺔ‬.

b.

Environmental conditions (‫)اﻟﻈﺮوف اﻟﻤﻨﺎﺧﻴﺔ اﻟﻤﺤﻴﻄﺔ‬.

c.

Available materials (‫)اﻟﻤﻮاد اﻟﻤﺘﻮﻓﺮة‬.

d.

Common practice (‫)اﻟﺨﺒﺮة اﻟﺸﺎﺋﻌﺔ‬.

e.

Cost (‫)اﻟﻜﻠﻔﺔ‬.

2. Cross Slop: 0.01 – 0.03 "high type surface" 0.08 "low type surface" Æ shoulders 3. Lane Width: -

Standard = 3.65m

-

In practice = 3.75 m

-

+0.25m (at shoulders) & +0.5m (at median if barrier curb is found). Where +0.25m & 0.50m marginal strips.

4. Shoulder: - Surface treatment Width = 2.5 - 3.0m Cross-slop = 5 - 8% = 0.05 - 0.08 01-1

Cross-Section Elements

Nov-2009


5. Curbs: -

Barrier (for pedestrian) (‫)ﻻ ﻳﻤﻜﻦ اﺟﺘﻴﺎزﻩ ﺑﺎﻟﻤﺮآﺒﺎت‬

-

Mountable (‫)ﻳﻤﻜﻦ اﺟﺘﻴﺎزﻩ ﺑﺎﻟﻤﺮآﺒﺎت‬

-

Curb & Gutter (‫)أﻧﻮاع ﻣﻦ اﻷرﺻﻔﺔ ﺗﺤﻮي ﻧﻈﺎم ﺗﺼﺮﻳﻒ‬

6. Guard rail (by sheet and column): Used at hazardous points: -

at high fill > 3.0m

-

steep grades (‫)اﻧﺤﺪار ﺷﺪﻳﺪ‬

-

sharp curvature (‫)اﻧﺤﻨﺎء ﺷﺪﻳﺪ‬

-

sudden change in alignment

-

restricted sight (foggy ‫)ﻣﻨﺎﻃﻖ اﻟﺮؤﻳﺔ اﻟﻤﻘﻴﺪة( )ﺿﺒﺎﺑﻲ‬

-

near rivers and lakes < 10 - 15m

7. Median: For: -

Separating opposite flow

-

Future expansion

W (m) 1.2 12

O (m) 30 9

01-2


Nov-2009


8. Side walk (‫)ﻃﺮﻳﻖ اﻟﻤﺸﺎة‬:

9. Side slop: a. Cut slop: -

For normal soil (clay, silt, sand), & h ≤ 6.0m: H:V = 2:1, … ..., 4:1 (favorable 4:1 ‫)اﻟﻤﻔﻀﻠﺔ‬

-

For normal soil, & h > 6.0m: (has to be design according to slop stability theory)

-

For rocky soil: Hard (H:V) = 1:10 … 1:5 Medium (H:V) = 1:4 … 1:3 Sift (H:V) = 1:2 with steps

b. Fill slop: ،‫أول ﺳ ﺘﺔ أﻣﺘ ﺎر ﺑﺎﻟﻤﻴ ﻞ اﻟﻤﺒ ﻴﻦ ﺑﺎﻟﺸ ﻜﻞ‬ (1:1) ‫( ﺑﺎﻟﻤﻴﻞ‬h) ‫واﻟﻤﺘﺒﻘﻲ‬

01-3


Nov-2009


‫ﻓ ﻲ ﺣﺎﻟ ﺔ وﺟ ﻮد ﻣﺴ ﻄﺢ ﻣ ﺎﺋﻲ ﺑﺠﺎﻧ ﺐ اﻟﻄﺮﻳ ﻖ ﺗﻜ ﻮن‬ ‫اﻟﺘﻔﺎﺻﻴﻞ آﻤﺎ ﻓﻲ اﻟﺸﻜﻞ‬

10.

Vertical clearance:

For roads = min. 5.20m For railway = min. 6.50m For walkway = min. 2.50m For main rivers = min. 6.50m For other rivers = min. 3.50m For high tension lines = min. 8.8 -10m 11.

Right of way (‫ ≥ )ﻣﺤﺮﻣﺎت اﻟﻄﺮﻳﻖ‬80m

Freeway ≈ 200m Highway ≈ 100m Used for: future expansion (‫)اﻟﺘﻮﺳﻊ‬, safety (‫)اﻷﻣﺎن‬, maintenance (‫)اﻟﺼﻴﺎﻧﺔ‬.

01-4


Nov-2009


02-Earthworks & Mass-Haul Diagram Mass-haul diagram: Continuous curve showing the relationship between the accumulated algebraic sums of corrected earthwork volume and distance for the purpose of minimizing the cost of excavating hauling & damping the materials (Soil).

-

Rising Æ Cut

-

Falling Æ Fill

-

Steep slop Æ High cut or fill

-

Zero slop Æ Change from cut to fill or vice versa.

-

Zero value Æ Balance between cut and fill

Haul (‫ = )اﻟﻨﻘﻞ‬Volume (m3) * Distance (sta.) Haul distance: The distance of moving the masses of soil from one place to another, in the process of earthwork. 02-1

Earthworks & Mass-Haul Diagram

Nov-2009


Free haul distance (F. H. D.): The distance within which there is a fixed price for excavating, hauling, and damping the materials regardless of the distance moved. Free haul ch arg e =

I.D m3

Over haul distance (O. H. D.): The distance beyond (F. H. D.) for which there is an additional price for each (m3.sta.) Over haul ch arg e = max . O. H. D. =

I.D m3.sta.

Borrow ch arg e O. H. ch arg e

Limit of economical haul distance (L. E. H. D.): The distance beyond which it is more economical to waste and borrow rather than to pay for the cost of over hauling. L. E. H. D. = F. H. D. + max. O. H. D. A-B = F. H. D. C-D = F. H. V. E-F = L. E. H. D. G-H = O. H. V. E-K = West (W) F-P = Borrow (B) ‫وآﻤﺜﺎل ﺗﺮﺳﻢ اﻟﻌﻼﻗﺔ ﺑﻴﻦ اﻟﻤﺴﺎﻓﺔ )ﺑﺎﻟﻤﺤﻄﺎت( ﻣ ﻊ اﻟﺤﺠ ﻮم اﻟﻤﺼ ﺤﺤﺔ اﻟﻤﺠﻤﻌ ﺔ ﻟﻘ ﻴﻢ ﻣﻌﻴﻨ ﺔ ﺑﻤﻘﻴ ﺎس رﺳ ﻢ ﻣﻌ ﻴﻦ ﻟﻠﺤﺼ ﻮل‬ ‫( وﺣﺴ ﺐ ﻣﻘﻴ ﺎس اﻟﺮﺳ ﻢ ﺗﺮﺳ ﻢ وﺗﻘ ﺎس‬3Sta.) ‫( هﻲ ﻣﺴﺎﻓﺔ اﻟﻨﻘﻞ اﻟﺤﺮ وﻣﻘﺪارهﺎ ﻟﻠﻤﺜﺎل ﺣ ﻮاﻟﻲ‬A-B) ،‫ﻋﻠﻰ ﻣﺨﻄﻂ ﻧﻘﻞ اﻟﻜﺘﻞ وﻣﻨﻬﺎ‬ ‫ ﺛ ﻢ ﻧﺮﺳ ﻢ اﻟﺤ ﺪ اﻻﻗﺘﺼ ﺎدي ﻟﻤﺴ ﺎﻓﺔ‬.(F. H. V.) ‫( وه ﻲ ﺣﺠ ﻢ اﻷﺗﺮﺑ ﺔ اﻟﻤﻨﻘﻮﻟ ﺔ ﺑﺼ ﻮرة ﺣ ﺮة‬A-B) ‫اﻟﻤﺴﺎﻓﺔ ﻣﻦ ﻗﻤﺔ اﻟﻤﻨﺤﻨﻲ ﻟﻠﺨ ﻂ‬ ‫ أﻣ ﺎ‬،‫( هﻲ ﺣﺠﻢ اﻟﺘﺮﺑﺔ اﻟﻤﻨﻘﻮﻟ ﺔ ﺑﺼ ﻮرة ﻣﻀ ﺎﻓﺔ ﺑﺼ ﻮرة ﻣﻨﺎﺳ ﺒﺔ‬G-H) ‫( وﺣﺴﺐ ﻣﻘﻴﺎس اﻟﺮﺳﻢ ﻓﺘﻜﻮن اﻟﻤﺴﺎﻓﺔ‬L. F. H. D.) ‫اﻟﻨﻘﻞ‬ .‫( اﻟﻔﺎﺋﺾ واﻟﻤﺴﺘﻌﺎر‬W, B) ‫( ﻓﻬﻲ‬E-F) ‫اﻟﺒﺎﻗﻲ ﺗﺤﺖ‬

02-2


Nov-2009


Correction:

M M

* Sandy, Silty clay

‫ﺗﺤﻤﻴﻞ‬

Shrinkage: 5 – 15 % ≈ 10%

Loose

V0

M

‫ﺣﺪل‬

V1

V2

V0 < V2 < V1 M

M

* Lime stone, Sand stone

‫ﺗﺤﻤﻴﻞ‬

Bulking: 25 – 35 % ≈ 30%

V0

Loose

M

‫ﺣﺪل‬

V1

V2

V2 < V1 V2 > V0

Ex.: Sta.

End Area (m2) Cut Fill 4.0 2.6

0+00 2+00

2

4+00

1.0

6+00

7

9+00

0

Cut + (m3)

(-) Shrinkage 10% (m3)

Corrected Cut + (m3)

Fill – (m3)

Balance Vol. (m3) (Cut-Fill)

0.5*(4+2)*200 =600

600*0.1 =60

600-60 =540

0.5*(2.6+0)*200 =260

+280

0.5*(2+1)*200 =300

300*0.1 =30

300-30 =270

0.5*(0+3)*200 =300

-30

0.5*(1+7)*200 =800

800*0.1 =80

800-80 =720

0.5*(3+2)*200 =500

+220

0.5*(7+0)*300 =1050

1050*0.1 =105

1050-105 =945

0.5*(2+8)*300 =1500

-555

0

Accu. Vol. (m3) 0 +280

3

+250

2

+470

8

-85

M-H. Diagram

Corrected accumulated volume (m3)

500 400 300 200 100 0 0

100

200

300

400

500

600

700

800

900

1000

-100 Distance (Sta.)

02-3


Nov-2009


03-Asphaltic Materials

Axel Load M. S. = (Marshall Stability) C.B.R. = (California bearing reaction)

Flexible Pavement Layers: M. S. ≥ 8 kN ≈ 10 kN M. S. ≥ 7 kN

Wearing (Surface) course Level (Binder) course

(Asphaltic concrete) (Asphaltic concrete)

M. S. ≥ 5 kN C. B. R. ≥ 80% C. B. R. ≥ 35% C. B. R. ≥ 5% ≈ 10%

Base course - Asphaltic concrete - Crushed stone - Subbase course Compacted subgrade

(Concrete) (Stabilized mater) (asphalt, concrete, lime) (Sand-gravel)

C. B. R. < 5% ≈ 4%

Natural subgrade

Asphaltic Concrete: -

Asphalt cement

-

Coarse aggregate (crushed gravel) [1" – No.4 (No.10)]

-

Fine aggregate (sand) [No.4 (No.10) – No.200]

-

Mineral filler (cement or lime) [≤ No.200]

-

Additives

Bituminous materials: Mixture of hydrocarbons (C, H), liquid or semisolid in consistency, soluble in CS2 & CCl4 -

Tar: produced by destructive distillation of coal (chemical change), cannot

found in nature, more susceptible to temp. & more toxis. -

Asphalt: produced by fractional distillation of petroleum (physical change),

natural (lakes, rocks) or manufactured, less susceptible to temp. & less toxic. Dura refinery:

Atmosphere Tower

Vacuum Tower

Medium distillation

Steam

Deasphaltive unit

Steam

(deasphaltive oil) Propane C3H8

o

370 C Red need oil ≈ 40%

Blending (a) and (b) (‫)ﺑﻌﺾ ﺣﺎﻻت اﻟﻤﺰج‬ to produce asphalt cement:

Vacuum (a) residue ≈ 18%

Heavy distillation

Base (b) Asphalt ≈ 13%

Blend

1 (a) + 1 (b) Æ AC (40-50) 1.8 (a) + 1 (b) Æ AC (60-70) 03-1

‫اﻟﻨﻔﻂ اﻟﺨﺎم ﺑﻌﺪ اﻟﺘﻘﻄﻴﺮ‬

Crude oil 100% [315oC]

Light distillation

Asphaltic Materials

Gasoline Kerosene Diesel Oil Lube Oil Asphalt + Paraffin

Nov-2009

Lectures of Highway Engineering – Forth Stage Manufactured Asphalt

Asphalt Cement

Liquid (Cut-back) Asphalt

Emulsified Asphalt

A) Asphalt Cement: a. Penetration grade: 40-50 ‫ اﻧﺘﺎج ﻗﻠﻴﻞ‬50-60 60-70 85-100 120-150 200-300

Less durable (‫)ﻗﻠﻴﻞ اﻟﺪﻳﻤﻮﻣﺔ‬ Less flexible (‫)ﻟﺪوﻧﺔ ﻗﻠﻴﻠﺔ‬

(Thermal Cracking)

More temperature susceptible (permanent deformation)

(Rutting)

b. Viscosity grade: Absolute viscosity (Dynamic): By Poise (

dyne * sec . ) cm 2

⎡ dγ (shear strain ) ⎤ rate of shear strain ⎜⎝ sec . ⎟⎠ ⎛ dyne ⎞ τ(shear stress ) ⎜ = η(Abs.Vis. (Poise) ).⎢ ⎥ ←⎯ ⎯ ⎯ ⎯ ⎯⎯⎯ 2 ⎟ ⎝ cm ⎠ ⎣ dt ( time (sec .)) ⎦ ⎛ 1 ⎞

‫ﻗﻠﻴﻞ اﻻﻧﺘﺎج‬ ‫ﻣﻬﻢ‬

Viscosity grade AC-40 AC-20 AC-10 AC-5 AC-2.5

o

Abs. Vis. @60 C = 40*100=4000 poise 2000 poise 1000 poise 500 poise 250 poise

Penetration grade > 20 > 40 > 70 > 120 > 200

Asphalt cement requirements (AC-20 [40-70]): 1. Basis of grading (Consistency) (‫)اﻟﻘﻮام‬ -

Abs. Viscosity @60oC = (1600 – 2400) poise

(Gs = 1.01 – 1.05) 2. Temperature susceptibility (‫)ﺣﺴﺎﺳﻴﺘﻬﺎ ﻟﻠﺤﺮارة‬: -

Penetration (‫)ﻓﺤﺺ اﻟﻐﺮز‬: (ST. condition – min. 40 (40-70) 1/10mm

Penetration after thin film oven test, retained pen. > 55% & (mass loss < 0.75%) -

Kinematics viscosity @135oC Æ Min. (210) Centistokes

(Stokes = 100 Centistokes) (Stoke = Poise/Density) 03-2

Asphaltic Materials

Nov-2009


3. Oxidative hardening (‫)اﻟﺘﺼﻠﺐ ﺑﺴﺒﺐ اﻻآﺴﺪة‬: -

Abs. viscosity @60oC after thin film oven test Æ Min. (10000) Poise

4. Homogeneity (‫)اﻟﺘﺠﺎﻧﺲ‬: -

Ductility after thin film oven test Æ Min. (20cm)

Ductility before thin film oven test Æ (≥ 100cm) @25oC (5cm/min.) -

Solubility in Trichloro-Ethelin Æ Min. (99%)

5. Safety: -

Flash point Æ Min. (232oC)

-

Softening point Æ (52 – 60oC)

Chemical components (AC): -

Aliphatic hydro carbons (Chain)

H

H

H

H

|

|

|

|

H − C − C − C − C − H | | | |

Light molecular weight

H

H

H

H

H |

-

Aromatic hydro carbons (Rings)

C

Heavy molecular weight

H −

/ C

\\ C − H

||

|

H −

C

C

\\

/

− H

C | H

Chemical Components: :‫وﺟﺪ أن ﺗﺮآﻴﺐ ﻋﻴﻨﺔ ﻣﻦ اﻻﺳﻔﻠﺖ هﻮ‬ [C89 H104 S3 N2 O2] :‫وﺗﺨﺘﻠﻒ أﻧﻮاع اﻻﺳﻔﻠﺖ ﻓﻲ ﻧﺴﺐ هﺬﻩ اﻟﻌﻨﺎﺻﺮ وﺗﺘﺮاوح ﺿﻤﻦ اﻟﺤﺪود اﻵﺗﻴﺔ‬ C = 70 – 85 %,

H = 7 – 12 %,

O = 0 – 5 %,

N=0–1%

S=1–7%

03-3

Asphaltic Materials

Nov-2009


Fractional Components of AC Asphaltene 1 Asphaltene 2 Nitrogen bases Maltenes

Role

Bonding agent (‫)اﻟﻘﻮام‬ Peptizing agent ( ‫ﻳﺴﺎﻋﺪ ﻋﻠﻰ اﻧ ﺪﻣﺎج اﻻﺳ ﻔﻠﺘﻴﻦ ﺑ ﺎﻻﺟﺰاء‬ ‫)اﻻﺧﺮى‬ 3 First acidaffines Solvent (‫)ﻣﻮاد ﻣﺬﻳﺒﺔ ﺗﺴﺎﻋﺪ ﻋﻠﻰ اﺣﺘﻮاء اﻟﻤﻮاد اﻻﺧﺮى‬ 4 Second acidaffines Solvent (‫)ﻣﻮاد ﻣﺬﻳﺒﺔ ﺗﺴﺎﻋﺪ ﻋﻠﻰ اﺣﺘﻮاء اﻟﻤﻮاد اﻻﺧﺮى‬ 5 Paraffin Gelling agent (‫)ﻋﺎﻣﻞ ﻣﺨﺜﺮ‬

(Durability) Reactivity to O2 Low High High Low Very low

B) Liquid (cut-back) Asphalt:

Asphalt cement + solvent (for temporary liquefaction) a. Rapid Curing (R.C): AC (85-100) + Gasoline RC-70 (ً‫)اﻻآﺜﺮ ﺷﻴﻮﻋﺎ‬ RC-250 RC-800 RC-3000

‫ ﻟﻠﻤﻨﺎﻃﻖ اﻟﺤﺎرة‬Kinamatic Vis. @60oC = 70-2*70 centestok ‫ﻟﻠﻤﻨﺎﻃﻖ اﻟﺒﺎردة‬

Used as Tack Coat: Thin film of asphalt applied (immediately before paving) between 2-paved layers (0.2-0.5 litter/m2) b. Medium Curing (M.C): AC (120-150) + Kerosene MC-30 MC-70 (ً‫ )اﻻآﺜﺮ ﺷﻴﻮﻋﺎ‬Tight Surface (‫)ﻣﺴﺎﺣﺎت ﺻﻐﻴﺮة‬ MC-270 (ً‫ )اﻻآﺜﺮ ﺷﻴﻮﻋﺎ‬Open Surface (‫)ﻣﺴﺎﺣﺎت آﺒﻴﺮة‬ MC-800 MC-3000

Used as Prime Coat: Film of asphalt applied (before 24hr of paving) between unpaved & paved layers (1.0-0.5 litter/m2) c. Slow Curing (S.C): AC (200-300) + Oils SC-70 SC-250 SC-800 SC-3000

For stabilizing earth works (‫)ﻟﺘﺜﺒﻴﺖ اﻷﻋﻤﺎل اﻟﺘﺮاﺑﻴﺔ‬

03-4

Asphaltic Materials

Nov-2009


C) Emulsified Asphalt:

Dispersing of asphalt particles in water in presence of emulsifying agent AC (non-polar) + Water (polar H+OH-) + surface active agent (emulsifier) ‫ اﻟﻤ ﺎدة اﻟﻤﺴ ﺎﻋﺪة ﺗﻤ ﻨﺢ ذرات اﻹﺳ ﻔﻠﺖ ﻗﻄﺒﻴ ﺔ ﻟﺘﻜ ﻮن ﻣﺴ ﺘﺤﻠﺒﺔ ﻓ ﻲ‬،‫ اﻟﻤﺎء ﻣ ﺎدة ﻣﺘﺄﻳﻨ ﺔ‬،‫* اﻹﺳﻔﻠﺖ ﻣﺎدة ﻏﻴﺮ ﻣﺘﺄﻳﻨﺔ‬ ‫اﻟﻤﺎء‬ ‫* ﺑﻌﺾ اﻟﻤﻮاد اﻟﻤﺴﺎﻋﺪة ﺗﻀﻴﻒ ﺷﺤﻨﺎت ﻣﻮﺟﺒﺔ أو ﺳﺎﻟﺒﺔ أآﺒﺮ ﻣﻦ اﻟﺜﺎﻧﻴ ﺔ واﻟﺘ ﻲ ﺗﺴ ﻤﺢ ﻓ ﻲ اﻟﺤﺼ ﻮل ﻋﻠ ﻰ ﺑﻌ ﺾ‬ ‫اﻟﺨﻮاص ﻟﻠﻤﺎدة اﻟﻤﺴﺘﺤﻠﺒﺔ‬ For: 1. Possibility of mixing with aggregate at normal temperature. 2. Water is safer and cheaper. :‫ﺗﺴﺘﻌﻤﻞ اﻟﻤﺴﺘﺤﻠﺒﺎت ﻋﻨﺪ اﻟﻤﺰج ﻣﻊ اﻟﺮآﺎم ﻷﻧﻬﺎ ﺗﻮﻓﺮ‬ ‫ اﻣﺘﺰاج اﻹﺳﻔﻠﺖ ﺑﺴﻄﺢ اﻟﺮآﺎم‬.1 ‫ إزاﻟﺔ اﻟﻤﺎء اﻟﻤﻮﺟﻮد ﻓﻲ ﻓﺠﻮات اﻟﺮآﺎم‬.2 ‫* ﻳﺤﺘﻮي ﺳﻄﺢ اﻟﺮآﺎم ﻋﻠﻰ ﺷﺤﻨﺎت ﻗﻄﺒﻴﺔ ﻣﻌﻴﻨﺔ ﻟﺬﻟﻚ اﺧﺘﻴﺎر ﻧﻮع اﻟﻌﺎﻣﻞ اﻟﻤﺴ ﺎﻋﺪ ﻳﺴ ﺎﻋﺪ ﻋﻠ ﻰ إﻳﺠ ﺎد ﺗ ﺮاﺑﻂ ﺑ ﻴﻦ‬ :‫ آﻤﺎ ﻓﻲ اﻟﻤﺨﻄﻂ أدﻧﺎﻩ‬،‫اﻹﺳﻔﻠﺖ وﺣﺒﻴﺒﺎت اﻟﺮآﺎم ﺑﺼﻮرة أﻓﻀﻞ‬ Emulsifying Type Anionic Emu. Asp. agent (Quality) Cationic Emu. Asp. Quantity

With lime stone (+) With Quartz & Silica (-)

Rapid setting As (tack coat) Medium setting As (prime coat with coarse agg.) Slow setting As (prime coat with fine agg.)

Anionic Emu. Asp. RS-1 & RS-2 MS-1, MS-2 MS-h SS-1 & SS-1h

Cationic Emu. Asp. CRS-1 & CRS-2

*

& CMS-2 & CMS-2h CSS-1 & SCC-1h

(-) ‫ ﻓﻲ ﺑﺪاﻳﺔ اﻟﺮﻣﺰ ﻣﻌﻨﺎﻩ أن اﻟﺸﺤﻨﺔ ﺳﺎﻟﺒﺔ‬C *

Setting: coalesance (separation) of asphalt from water

Note: (2) more viscose than (1) (‫)أآﺜﺮ ﻟﺰوﺟﺔ‬ (2h) harder asphalt (residue) (‫ )اﻟﻤﺘﺒﻘﻲ ﺑﻌﺪ ﺗﺒﺨﺮ اﻟﻤﺎء‬than (2) (1h) harder asphalt (residue) than (1)

03-5

Asphaltic Materials

Nov-2009


Important properties of Asphalt:

1. Hardening with time (Oxidation, Volatilization of light components) ‫زﻳﺎدة اﻟﺼﻼﺑﺔ ﺑﻤﺮور اﻟﺰﻣﻦ ﺑﺴﺒﺐ اﻟﺘﺄآﺴﺪ وﺗﺒﺨﺮ اﻟﻤﻮاد اﻟﻤﺬﻳﺒﺔ اﻟﺨﻔﻴﻔﺔ‬ 2. Thermoplastic materials (Consistency varies with temperature) (η) ‫ﻣﺎدة ﻣﺮﻧﺔ ﺑﺎﻟﺤﺮارة )اﻟﻠﺪوﻧﺔ ﺗﺘﻐﻴﺮ ﺑﺘﻐﻴﺮ اﻟﺤﺮارة( وﻣﻘﻴﺎس اﻟﻠﺪوﻧﺔ هﻲ اﻟﻠﺰوﺟﺔ‬ Log η (Abs. Viscosity)

Log T (Temp.) (Abs. Temp.)

3. Rheological materials (Stress-Strain behavior is time depending) ‫ وﻟﺪراﺳﺔ وﺗﻤﺜﻴﻞ ﺗﺼﺮف اﻟﻤﻮاد اﻻﺳﻔﻠﺘﻴﺔ اﻟﺘﻲ هﻲ وﺳﻂ ﺑﻴﻦ اﻟﻤﻮاد‬،‫هﻨﺎك ﻋﻼﻗﺔ ﺑﻴﻦ اﻻﺟﻬﺎد واﻻﻧﻔﻌﺎل ﻣﻊ اﻟﺰﻣﻦ‬ :‫ وآﻤﺎ ﻳﺄﺗﻲ‬.‫اﻟﻠﺪﻧﺔ واﻟﻤﻮاد اﻟﻠﺰﺟﺔ ﻳﺠﺐ دراﺳﺔ ﺗﺼﺮﻓﺎت اﻟﻤﻮاد اﻟﺒﻼﺳﺘﻴﻜﻴﺔ واﻟﻠﺰﺟﺔ‬ Elastic materials:

-

Stress-strain in time independent.

-

No permanent deformation (all recoverable after unloading).

-

Instantaneous deformation while loading.

-

Follow Hook's low. τ (shear stress) = G (shear modulus) * γ (shear strain)

-

"Spring" may represent such behavior. τ = constant γ

‫ﺑﻘﺎء اﻟﺘﺸﻮﻩ ﺑﺒﻘﺎء اﻟﺤﻤﻞ‬

(Spring) ‫ﻋﻨﺪ ﺗﺴﻠﻴﻂ اﻟﺤﻤﻞ ﻋﻠﻰ‬ ‫ﺣﺪوث ﺗﺸﻮﻩ ﺁﻧﻲ‬ tu

t

Unload time

03-6

Asphaltic Materials

Nov-2009


Viscous materials:

-

Stress-Strain is time dependent.

-

No immediate deformation.

-

No recovery of deformation (all deformation are permanents).

-

Follows Newton's law. τ (shear stress) = η(abs. vis.)

-

dγ (rate of shear strain) dt

Dash-pot may represent such behavior. τ = constant γ

‫ﺑﻌﺪ رﻓﻊ اﻟﺤﻤﻞ‬

‫ﻋﻨﺪ اﻟﺘﺤﻤﻴﻞ‬ (‫)ﺗﺸﻮﻩ ﺗﺪرﻳﺠﻲ‬

τ η

‫ﺛﻘﻮب‬ Asphalt

t

tu Unload time

But Asphalt may be viscoelastic material.

:‫وﻟﻠﺘﻌﺒﻴﺮ ﻋﻦ هﺬﻩ اﻟﺤﺎﻟﺔ هﻨﺎك ﻣﺠﻤﻮﻋﺔ ﻣﻦ اﻟﻤﻮدﻳﻼت اﻟﺮﻳﺎﺿﻴﺔ‬ By Maxwell model: τ=η

dγ ← γ 2 dt ← tu

γ1

τ * tu γ2 = η

γtotal = γ1 + γ2 γ total

τ τ = + * t ← Anytime G η

γ

γ1 = γ2

γ2

τ η

τ G γ2 =

γ1

τ * tu η

tu

03-7

t

Asphaltic Materials

Nov-2009


By Kelvin or Voight model: γ=

γ

γ=

τ *F G

F≤1 When t = ∞

τ G

τ G

− t⎞ τ⎛ γ = ⎜1 − e η ⎟ ⎟ G ⎜⎝ ⎠ G

tu

F = 1− e

γ=

τ G

t

G − *t η

No instantaneous deformation No permanent deformation But related elasticity By Burger (4-element) model [of asphaltic material]: γ1

η2

γ2

γ

elastic

G1

G2 inelastic

γ1 =

γ3

τ η3

γ2 γ3

η3

viscous

τ G1

γ2

γ3 =

γ1

τ * tu η3

tu

t

For loading curve: G − 2t ⎞ τ τ ⎛⎜ τ γ= + 1 − e η2 ⎟ + * t ⎟ η3 G1 G 2 ⎜⎝ ⎠

:‫ﻣﻼﺣﻈﺔ‬ ‫ﻟﻄﺒﻘﺎت اﻟﺘﺒﻠﻴﻂ اﻟﻤﺮﻧﺔ ﻳﻜﻮن ﻓﻴﻬﺎ ﻗﺴﻢ ﻣﻦ اﻟﺘﺸﻮﻩ وﻗﺘﻲ ﻳﺮﺟﻊ ﺑﺴﺮﻋﺔ وﻗﺴﻢ ﺁﺧﺮ ﻳﺮﺟﻊ ﺑﻤﺮور اﻟﺰﻣﻦ واﻟﻘﺴﻢ اﻟﺜﺎﻟ ﺚ ﺻ ﻐﻴﺮ‬ ‫ )اﻟﻘﺴﻢ اﻟﺜﺎﻟﺚ ﻳﺤ ﺪث ﻏﺎﻟﺒ ًﺎ ﻓ ﻲ ﺟﺎﻧ ﺐ اﻟﻤﻤ ﺮ اﻟﺨ ﺎرﺟﻲ ﻟﻠﻄﺮﻳ ﻖ ﺣﻴ ﺚ اﻷﺣﻤ ﺎل اﻟﻤﺮورﻳ ﺔ اﻟﺒﻄﻴﺌ ﺔ‬.‫أو ﻗﻠﻴﻞ اﻟﺤﺪوث ﻳﻜﻮن ﻓﻴﻬﺎ داﺋﻤﻲ‬ ((Parking) ‫ وآﺬﻟﻚ ﻳﺤﺪث ﻓﻲ ﻣﻨﺎﻃﻖ اﻟﻮﻗﻮف‬،‫واﻟﺜﻘﻴﻠﺔ وﻋﺪم آﻔﺎءة اﻟﺘﺒﻠﻴﻂ‬

03-8

Asphaltic Materials

Nov-2009


04-Aggregate: Natural

Igneous (Granite) Sedimentary (sand, gravel, sandstone, and limestone) Metamorphic (Marble)

Industrial product

Slag (‫)ﻣﺨﻠﻔﺎت أﻓﺮان اﻟﺤﺪﻳﺪ‬ Clinker (‫)ﻣﺨﻠﻔﺎت أﻓﺮان اﻟﻔﺤﻢ‬

Main desirable properties of aggregate: 1) Inter particle friction (Mechanism of load transfer): :‫ وﻳﻤﻜﻦ اﻟﺴﻴﻄﺮة ﻋﻠﻴﻪ ﻣﻦ ﺧﻼل‬،(‫ﻣﻴﻜﺎﻧﻴﻜﻴﺔ اﻧﺘﻘﺎل اﻷﺣﻤﺎل )اﻻﺣﺘﻜﺎك اﻟﺪاﺧﻠﻲ‬ a. Surface texture (rough or smooth): Resistance to displacement b. Particle shape (angularity) ‫( اﻟﺘﺰوّي‬round, fractured, & cubical) :‫ﻳﻘﻴﻢ ﻋﻦ ﻃﺮﻳﻖ‬

Angularity No. (0-10%) = % voids in round (≈33%) - % voids in any shape ‫( آﻠﻤﺎ آﺎن اﻟﺮآﺎم أﻓﻀﻞ‬10%) ‫وآﻠﻤﺎ اﻗﺘﺮﺑﺖ اﻟﻘﻴﻤﺔ ﻣﻦ‬

c. Gradation ‫( اﻟﺘﻮزﻳﻊ اﻟﺤﺒﻴﺒﻲ‬dense, gap, & open graded) :‫ﻳﻘﻴﻢ ﻋﻦ ﻃﺮﻳﻖ‬ P ⎡d⎤ =⎢ ⎥ By Fuller (dense gradation) = 100 ⎣ D ⎦

1

2

Where: D = diameter of max. size particle Æ (passing 100%); inch d = size of opening for any sieve, inch P = percent passing of that sieve. :‫وﺗﺴﺘﻌﻤﻞ اﻟﻤﻨﺎﺧﻞ ﻓﻲ إﻳﺠﺎد ﺣﺠﻢ اﻟﺤﺒﻴﺒﺎت اﻟﻤﻄﻠﻮب وهﻲ آﻤﺎ ﻳﻠﻲ‬ 2", 1.5", 1", 3/4", 1/2", 3/8", No.4, …. .‫ ﻣﻌﻨﺎهﺎ ﺗﻮﺟﺪ أرﺑﻌﺔ ﺛﻘﻮب ﻓﻲ اﻷﻧﺞ اﻟﻤﺮﺑﻊ اﻟﻮاﺣﺪ‬No.4 :‫ ﻓﻨﺴﺘﺨﺮج ﺑﻘﻴﺔ اﻟﻨﺴﺐ ﻣﻦ اﻟﻘﺎﻧﻮن أﻋﻼﻩ وآﻨﺎ ﻳﺄﺗﻲ‬،1" ‫ إذا آﺎن اﻟﻤﻄﻠﻮب ﺗﺼﻤﻴﻢ ﺧﻠﻄﺔ ﺗﺤﻮي ﻋﻠﻰ رآﺎم أآﺒﺮ ﻗﻄﺮ ﻓﻴﻪ‬:‫ﻣﺜﺎل‬

04-1

Aggregate

Nov-2009


1" 1/2"

Æ Æ

100%

3/8"

Æ

⎡ 3 "⎤ P=⎢ 8 ⎥ ⎢ 1" ⎥ ⎣ ⎦

0.5

⎡ 1 "⎤ P = ⎢ 2 ⎥ *100 = 70% ⎢ 1" ⎥ ⎣ ⎦ 0.5

*100 = 61%

.‫اﻟﺦ ﻣﻦ اﻟﻤﻨﺎﺧﻞ‬...

2) Durability (‫)اﻟﺪﻳﻤﻮﻣﺔ‬: The resistance to: a. Crashing (‫)اﻟﻄﺤﻦ أو اﻟﺴﺤﻖ‬: Crashing Value =

40 Tons

wt. of mat. pas sin g No.7 Original wt.

≤ 12% (≈ 8%)

(1/2" – 3/8") ‫ وﻣﺘﺒﻘﻲ‬1/2" ‫رآﺎم ﻣﺎر ﻣﻦ ﻣﻨﺨﻞ‬ 3/8" ‫ﻋﻠﻰ اﻟﻤﻨﺨﻞ‬

b. Degradation (‫)اﻟﺘﻜﺴﺮ ﺑﺴﺒﺐ اﻟﺘﺄﺛﻴﺮ اﻟﻤﻴﻜﺎﻧﻴﻜﻲ‬: % of wear by L. A. Operation, (‫)ﻃﺮﻳﻘﺔ ﻟﻮس أﻧﺠﻠﺲ‬ 2.5kg (3/4"-1/2") + 2.5kg (1/2"-3/8") & Spheres (500 revolution) Degradation =

wt. of mat. pas sin g No.12 ≤ 30% Original wt.

c. Disintegration (‫)اﻟﺘﻜﺴﺮ ﺑﺴﺒﺐ اﻟﺘﺄﺛﻴﺮ اﻟﻜﻴﻤﻴﺎﺋﻲ‬: 670 gm 330 gm 300 gm 1300 gm

(3/4" – 1/2") (1/2" – 3/8") (3/8" – No.4)

* Soundness for 16-18 hours & drying Cycle

By Na2SO4 (‫)آﺒﺮﻳﺘﺎت اﻟﺼﻮدﻳﻮم‬

≤ 12%

By MgSO4 (‫)آﺒﺮﻳﺘﺎت اﻟﻤﻐﻨﻴﺴﻴﻮم‬

≤ 18 %

3) Wet ability (‫)ﻗﺎﺑﻠﻴ ﺔ اﻟﺘﺮﻃﻴ ﺐ‬: adhesion with asphalt, or resistance to stripping of asphalt film from aggregate in the presence of water. a. Mechanical interlock: (‫)اﻟﺘﺄﺛﻴﺮ اﻟﻤﻴﻜﺎﻧﻴﻜﻲ‬ - Rough surface texture. (‫)ﺳﻄﺢ ﺧﺸﻦ‬ - Porous aggregate. (‫ ﻟﻀﻤﺎن ﺗﺪاﺧﻞ اﻹﺳﻔﻠﺖ وﻋﺪم اﻧﻔﺼﺎﻟﻪ ﺑﺎﻟﻤﺎء‬،‫)ﻣﺴﺎﻣﻴﺔ ﺳﻄﺤﻴﺔ ﻋﺎﻟﻴﺔ وﻟﻜﻦ ﻏﻴﺮ ﻣﺆﺛﺮة ﻋﻠﻰ اﻟﻘﻮة‬ - No surface coating. (‫)إزاﻟﺔ اﻷﺗﺮﺑﺔ اﻟﻤﺤﻴﻄﺔ ﺑﺎﻟﺮآﺎم‬ 04-2

Aggregate

Nov-2009


b. Chemical reactivity: (‫)اﻟﺘﺄﺛﻴﺮ اﻟﻜﻴﻤﻴﺎﺋﻲ‬ Basic minerals (of aggregate) (‫اﻟﻤﻮاد اﻷوﻟﻴﺔ )اﻟﺮآﺎم‬

+

Acidic portion (of asphalt)

Æ

Compound not soluble in water

(‫ﻣﻮاد ﺣﺎﻣﻀﻴﺔ )ﻓﻲ اﻹﺳﻔﻠﺖ‬

‫ﻣﺮآﺐ ﻏﻴﺮ ذاﺋﺐ ﻓﻲ اﻟﻤﺎء‬

c. Interfacial tension: (‫)اﻟﺸﺪ اﻟﺴﻄﺤﻲ ﺑﺴﺒﺐ اﻟﺸﺤﻨﺎت‬ - Hydrophobic aggregate (water-hating) (‫)ﻏﻴﺮ ﻣﺄﻟﻮف ﻟﻠﻤﺎء‬ - Hydrophilic aggregate (water-loving) (‫)ﻳﺄﻟﻒ اﻟﻤﺎء‬ .‫ أﻏﻠﺐ اﻟﺮآﺎم اﻟﻌﺮاﻗﻲ ﻣﻦ اﻟﻨﻮع اﻟﺜﺎﻧﻲ )أﻟﻴﻒ ﻟﻠﻤﺎء( ﻟﺬﻟﻚ ﻳﺠﺐ ﻣﺮاﻋﺎة ذﻟﻚ‬.‫واﻟﻤﻔﻀﻞ ﻣﻨﻬﺎ ﻏﻴﺮ اﻟﻤﺄﻟﻮف ﻟﻠﻤﺎء‬

Aggregate combination (blending) & separation to meet Job Mix requirement: ‫أو ﻓﺼ ﻞ ﻟﺘ ﺪرﺟﺎت اﻟﺮآ ﺎم‬/‫ ﻟ ﺬﻟﻚ ﻧﺤﺘ ﺎج إﻟ ﻰ ﻋﻤﻠﻴ ﺔ دﻣ ﺞ و‬،‫اﻟﺮآ ﺎم اﻟﻄﺒﻴﻌ ﻲ ﻏﺎﻟﺒ ًﺎ ﻻ ﻳﻜ ﻮن ﺿ ﻤﻦ اﻟﻤﻮاﺻ ﻔﺎت اﻟﺨﺎﺻ ﺔ ﺑﺎﻟﺘ ﺪرج‬ :‫ﻟﻠﺤﺼﻮل ﻋﻠﻰ ﺗﺪرج ﻣﻘﺎرب ﻟﻤﻌﺎدﻟﺔ اﻟﺨﻠﻂ‬

1. Discarding the over size. (‫)إﺑﻌﺎد اﻟﺤﺠﻮم اﻷآﺒﺮ ﻣﻦ اﻟﺤﺠﻢ اﻷﻗﺼﻰ ﻟﻠﺮآﺎم‬

2. Separating into two or more portions on selected proper sieve. (‫)ﻓﺼﻞ اﻟﺮآﺎم إﻟﻰ ﺟﺰﺋﻴﻦ أو أآﺜﺮ ﻓﻲ ﻣﻨﻄﻘﺔ اﻟﺨﻠﻞ‬

3. Recombining using proper percentage for recombination with specification requirement (mid-specification limits). (‫)إﻋﺎدة دﻣﺞ اﻷﺟﺰاء ﺑﻨﺴﺐ ﻣﺌﻮﻳﺔ ﻣﻨﺎﺳﺒﺔ ﻟﺘﺘﻼﺋﻢ وﻣﻮاﺻﻔﺎت اﻟﺘﺪرج( )ﻣﻨﺘﺼﻒ اﻟﻤﻮاﺻﻔﺔ‬

4. Addition of fine materials (& Filler) if necessary. (‫)إﺿﺎﻓﺔ رآﺎم ﻧﺎﻋﻢ )ﻣﻮاد ﻣﺎﻟﺌﺔ( ﻋﻨﺪ اﻟﺤﺎﺟﺔ‬

04-3

Aggregate

‫‪Nov-2009‬‬

‫‪Lectures of Highway Engineering – Forth Stage‬‬

‫‪Ex.:‬‬ ‫‪Specifications‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪95 – 65‬‬ ‫‪60 – 40‬‬ ‫‪40 – 24‬‬ ‫‪30 – 20‬‬ ‫‪20 – 10‬‬ ‫‪10 – 5‬‬ ‫‪5–3‬‬

‫‪(% passing) Natural grading‬‬ ‫‪100‬‬ ‫‪90‬‬ ‫‪80‬‬ ‫‪60‬‬ ‫‪40‬‬ ‫‪30‬‬ ‫‪20‬‬ ‫‪10‬‬ ‫‪5‬‬

‫‪Sieve size‬‬ ‫"‪1‬‬ ‫"‪3/4‬‬ ‫"‪1/2‬‬ ‫"‪3/8‬‬ ‫‪No.4‬‬ ‫‪No.10‬‬ ‫‪No.40‬‬ ‫‪No.80‬‬ ‫‪No.200‬‬

‫‪Sol.:‬‬ ‫ﻃﺮﻳﻘﺔ اﻟﺤﻞ‪:‬‬ ‫‪ .1‬إزاﻟﺔ اﻟﺤﺠﻢ ﻓﻮق اﻟﺤﺠ ﻢ اﻷﻗﺼ ﻰ )‪ :(Discard Oversize‬ﻧﻼﺣ ﻆ أن اﻟﺤﺠ ﻢ اﻷﻗﺼ ﻰ ﻟﻠﺮآ ﺎم ﺿ ﻤﻦ اﻟﻤﻮاﺻ ﻔﺎت )"‪ (3/4‬ﻟ ﺬﻟﻚ‬ ‫ﻳﺠﺐ إزاﻟﺔ اﻟﺤﺠﻮم ﺑﻴﻦ )"‪ (1"-3/4‬أي ﺟﻌﻞ اﻟﻤﺎر ﻣﻦ اﻟﻤﻨﺨﻞ )"‪ (100%) (3/4‬وﺗﺼﺤﻴﺢ ﺗﺪرج ﺑﺎﻗﻲ اﻟﻤﻨﺎﺧﻞ‪.‬‬ ‫‪ .2‬ﺑﻌﺪ اﻟﻤﺮﺣﻠﺔ اﻷوﻟﻰ ﻧﺤﺪد ﺑﺪاﻳ ﺔ اﻟﺨﻠ ﻞ ﻓ ﻲ أي ﻣ ﻦ اﻟﻤﻨﺎﺧ ﻞ‪ ،‬وﻧﻼﺣ ﻆ أن ﻣﻨﻄﻘ ﺔ اﻟﺨﻠ ﻞ ﻣ ﻊ اﻟﻤﻮاﺻ ﻔﺎت ه ﻲ ﻋﻨ ﺪ اﻟﻤﻨﺨ ﻞ )"‪(3/8‬‬ ‫وآﻤﻴ ﺔ اﻟﻤ ﺎر )‪ (67‬وه ﻲ ﻣﺘﺠ ﺎوزة ﻟﻠﻤﻮاﺻ ﻔﺔ )‪ ،(40-60‬ﻟ ﺬﻟﻚ ﻳ ﺘﻢ ﻓﺼ ﻞ اﻟﻤﻘ ﺎدﻳﺮ ﻋﻨ ﺪ اﻟﻤﻨﺨ ﻞ )"‪ (3/8‬واﻟ ﺬي ﻓﻴ ﻪ اﻟﺨﻠ ﻞ إﻟ ﻰ‬ ‫ﻣﺠﻤﻮﻋﺘﻴﻦ ﺛﻢ ﻳﺘﻢ اﻟﻤﺰج ﺑﻨﺴﺐ ﺑﻤﺤﺎوﻟﺔ وﺧﻄﺄ ﻟﻠﻮﺻﻮل ﻟﻠﻨﺴﺐ اﻟﻤﻨﺎﺳﺒﺔ ﻟﺘﺼﺤﻴﺢ اﻟﺘﺪرج‪.‬‬ ‫)‪(8‬‬ ‫)‪(C‬‬ ‫‪50% A‬‬ ‫‪+‬‬ ‫‪50% B‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪83‬‬ ‫‪50‬‬ ‫‪33‬‬ ‫‪26‬‬ ‫‪16‬‬ ‫‪8‬‬ ‫‪4.5‬‬

‫)‪(7‬‬ ‫)‪(B‬‬ ‫‪Portion‬‬ ‫‪passing‬‬ ‫"‪3/8‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪67‬‬ ‫‪0‬‬ ‫‪0‬‬ ‫‪0‬‬ ‫‪0‬‬ ‫‪0‬‬ ‫‪0‬‬

‫)‪(6‬‬ ‫‪Percent‬‬ ‫‪retained‬‬ ‫)‪(5)-(4‬‬ ‫‪0–0‬‬ ‫‪0–0‬‬ ‫‪11 – 33‬‬ ‫‪33 – 100‬‬

‫)‪(5‬‬ ‫)‪(A‬‬ ‫)‪Step (2‬‬ ‫‪Portion Passing‬‬ ‫"‪3/8‬‬ ‫‬‫‬‫‬‫‪100‬‬ ‫‪(100/67)*45=67‬‬ ‫‪(100/67)*34=51‬‬ ‫‪(100/67)*22=33‬‬ ‫‪(100/67)*11=16‬‬ ‫‪(100/67)*6=9‬‬

‫)‪(4‬‬ ‫)‪Step (1‬‬ ‫‪Portion passing‬‬ ‫"‪3/4‬‬

‫)‪(3‬‬ ‫‪Specifications‬‬

‫)‪(2‬‬ ‫)‪(% passing‬‬ ‫‪Natural‬‬ ‫‪grading‬‬

‫)‪(1‬‬ ‫‪Sieve‬‬ ‫‪size‬‬

‫‪100‬‬ ‫‪100‬‬ ‫‪(100/90)*80=89‬‬ ‫‪(100/90)*60=67‬‬ ‫‪(100/90)*40=45‬‬ ‫‪(100/90)*30=34‬‬ ‫‪(100/90)*20=22‬‬ ‫‪(100/90)*10=11‬‬ ‫‪(100/90)*5=6‬‬

‫‪100‬‬ ‫‪100‬‬ ‫‪95 – 65‬‬ ‫‪60 – 40‬‬ ‫‪40 – 24‬‬ ‫‪30 – 20‬‬ ‫‪20 – 10‬‬ ‫‪10 – 5‬‬ ‫‪5–3‬‬

‫‪100‬‬ ‫‪90‬‬ ‫‪80‬‬ ‫‪60‬‬ ‫‪40‬‬ ‫‪30‬‬ ‫‪20‬‬ ‫‪10‬‬ ‫‪5‬‬

‫"‪1‬‬ ‫"‪3/4‬‬ ‫"‪1/2‬‬ ‫"‪3/8‬‬ ‫‪No.4‬‬ ‫‪No.10‬‬ ‫‪No.40‬‬ ‫‪No.80‬‬ ‫‪No.200‬‬

‫ﻼ أي ان اﻟﺮآ ﺎم ﻻ ﻳﺤ ﻮﻳﻌﻠﻰ ﻣ ﻮاد ﻧﺎﻋﻤ ﺔ ﻣ ﻦ اﻟﺒﺪاﻳ ﺔ وﻻ ﻳﻤﻜ ﻦ ﺗﺼ ﺤﻴﺤﻪ ﺑﺈﻋ ﺎدة اﻟﺘﻮزﻳ ﻊ ﺑ ﻞ‬ ‫إذا آﺎﻧﺖ ﻧﺴ ﺒﺔ اﻟﻤ ﺎﻟﺊ )‪ (1)= (4.5‬ﻣ ﺜ ً‬ ‫ﺑﺈﺿﺎﻓﺔ )‪.(filler‬‬ ‫)‪(5‬‬ ‫‪97% C + 3% D‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪83.5‬‬ ‫‪51.5‬‬ ‫‪35‬‬ ‫‪22.25‬‬ ‫‪18.5‬‬ ‫‪10.75‬‬ ‫‪4‬‬ ‫‪Aggregate‬‬

‫)‪(4‬‬ ‫)‪(D‬‬ ‫‪Filler‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬ ‫‪100‬‬

‫)‪(3‬‬ ‫)‪(C‬‬

‫)‪(2‬‬ ‫‪Specifications‬‬

‫)‪(1‬‬ ‫‪Sieve size‬‬

‫‪100‬‬ ‫‪100‬‬ ‫‪83‬‬ ‫‪50‬‬ ‫‪33‬‬ ‫‪26‬‬ ‫‪16‬‬ ‫‪8‬‬ ‫‪1‬‬

‫‪100‬‬ ‫‪100‬‬ ‫‪95 – 65‬‬ ‫‪60 – 40‬‬ ‫‪40 – 24‬‬ ‫‪30 – 20‬‬ ‫‪20 – 10‬‬ ‫‪10 – 5‬‬ ‫‪5–3‬‬

‫"‪1‬‬ ‫"‪3/4‬‬ ‫"‪1/2‬‬ ‫"‪3/8‬‬ ‫‪No.4‬‬ ‫‪No.10‬‬ ‫‪No.40‬‬ ‫‪No.80‬‬ ‫‪No.200‬‬

‫‪04-4‬‬

Nov-2009


Ex.: Sieve 1" 1/2" No.4 No.10 No.40 No.80 No.200

Stock (A) Passing 100 63 19 8 5 3 2

Stock (B) Passing

Stock (C) Passing

100 92 55 36 3

Specification 100 70 – 85 40 – 55 30 – 42 20 – 30 12 – 22 5 – 10

100 97 88

Sol.: :‫ﻃﺮﻳﻘﺔ اﻟﺤﻞ‬ (No.200) ‫ وﻏﺎﻟﺒ ًﺎ ﻧﺒ ﺪأ ﺑﺎﻟﻨﺨ ﻞ‬،‫ﺗﻜﻮن ﻃﺮﻳﻘﺔ اﻟﺤﻞ ﺑﻄﺮﻳﻘﺔ اﻟﻤﺤﺎوﻟﺔ واﻟﺨﻄﺄ ﺑﻔﺮض ﻧﺴ ﺐ ﻣ ﺰج وﻣﻘﺎرﻧﺘﻬ ﺎ ﻣ ﻊ ﻣﻨﺘﺼ ﻒ اﻟﻤﻮاﺻ ﻔﺔ‬ (No.200) ‫( ﻧﺴ ﺒﺔ اﻟﻤ ﺎر ﻣ ﻦ اﻟﻤﻨﺨ ﻞ‬C) ‫ أي ﺑﻤ ﺎ أن ﻟﻠﻜﻮﻣ ﺔ‬،(Passing) ‫وﻧﻔﺮض ﻟﻪ ﻧﺴﺒﺔ ﺻﻐﻴﺮة ﻟﻠﻜﻮﻣ ﺔ ذا اﻟﻤﺤﺘ ﻮى اﻟﻌ ﺎﻟﻲ ﻣ ﻦ‬ (A, B) ‫( ﻓﻴﺠﺐ إﻋﻄﺎءهﺎ ﻧﺴﺒﺔ ﻗﻠﻴﻠﺔ وإﻋﻄﺎء ﻧﺴﺐ أآﺒﺮ ﻟﻠﻜﻮﻣﺘﻴﻦ‬5-10) ‫( واﻟﻤﻮاﺻﻔﺔ‬88) ‫ﻳﺴﺎوي‬

Sieve 1" 1/2" No.4 No.10 No.40 No.80 No.200 ‫ﻧﺴﺐ اﻟﻤﺰج‬

Stock (A) Passing 100 63 19 8 5 3 2 65%

Stock (B) Passing 100 92 55 36 3 30%

Stock (C) Passing

Specification 100 70 – 85 40 – 55 30 – 42 20 – 30 12 – 22 5 – 10

100 97 88 5%

04-5

Mid Specification 100 77.5 47.5 36 25 17 7.5

Passing %

Aggregate

100 76 47 38 25 18 7

Nov-2009


05-Asphalt Paving Mixture: :‫ﻳﺠﺐ أن ﺗﺘﻮﻓﺮ ﻋﺪد ﻣﻦ اﻟﺨﻮاص اﻟﺘﻲ ﺗﺤﺪد آﻔﺎءة اﻷﺳﻔﻠﺖ‬

Function: - Smooth riding quality surface. (‫)ﻧﻌﻮﻣﺔ ﺳﻄﺤﻴﺔ ﻟﻀﻤﺎن ﻧﻮﻋﻴﺔ ﺳﻴﺮ ﻣﻨﺎﺳﺒﺔ‬ - Safety. (‫)اﻷﻣﺎن‬ - Load carrying median. (‫)ﻳﻤﻜﻦ ﺗﺤﻤﻞ اﻷﺣﻤﺎل اﻟﻤﺮورﻳﺔ اﻟﻤﺴﻠﻄﺔ اﻟﻤﺘﻮﻗﻌﺔ‬ Note: •

Batch plant: percentage depend on weight. Continuous plant: percentage depend on volume.

•

Hot mix: after heating aggregate & asphalt. Cold mix: mixing at normal temperature (emulsified asphalt).

•

Dense mix: % air voids ≤ 10%. Open mix: % air voids > 10%.

Desirable properties: 1) Stability (‫)اﻟﺜﺒﺎت‬: resistance to permanent deformation. (‫)ﻣﻘﺎوﻣﺔ اﻟﺨﻠﻴﻂ ﻟﻠﺘﺸﻮﻩ اﻟﺪاﺋﻤﻲ‬

Affected by: • Frictional resistance (‫)اﻟﻤﻘﺎوﻣ ﺔ اﻟﻨﺎﺗﺠ ﺔ ﻣ ﻦ اﻻﺣﺘﻜ ﺎك‬: rough surface texture (of aggregate), optimum asphalt content, & dense gradation with compaction. (‫ ﺗﺪرج آﺜﻴﻒ ﻣﻊ اﻟﺮص‬،‫ ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ اﻟﻤﺜﻠﻰ‬،‫)ﺧﺸﻮﻧﺔ اﻟﺮآﺎم‬

• Cohesion (‫)اﻟﺘﻤﺎﺳ ﻚ‬: reology of asphalt, adhesion with aggregate, & surface area of aggregate (filler 3-8%). (‫)آﻠﻤﺎ ﻧﺰداد ﻣﺴﺎﺣﺔ اﻟﺮآﺎم ﻳﺰداد اﻟﺘﻼﺻﻖ ﺑﻴﻨﻪ وﺑﻴﻦ اﻷﺳﻔﻠﺖ ﻟﺬﻟﻚ ﻧﺴﺒﺔ اﻟﻤﺎﻟﺊ ﻣﻬﻤﺔ ﻓﻲ زﻳﺎدة اﻟﺜﺒﺎت‬

• Inertia of pavement: speed of vehicles, concentration of load, & axle load. (‫ واﻟﺤﻤﻞ اﻟﻤﺤﻮري‬،‫ ﺗﺮآﻴﺰ اﻷﺣﻤﺎل‬،‫)ﺳﺮع اﻟﻤﺮآﺒﺎت‬

2) Durability (‫)اﻟﺪﻳﻤﻮﻣ ﺔ‬: resistance to weathering (air, water, & oil) & abrasive action of traffic. ‫( وﻣﻘﺎﻣ ﺔ‬Stripping ‫ اﻟﻤ ﺎء واﻟﻤ ﻮاد اﻟﻨﻔﻄﻴ ﺔ ﺗﺴ ﺒﺐ ﻓﺼ ﻞ اﻟﻤ ﻮاد‬،Oxidation ‫)ﻣﻘﺎوﻣ ﺔ اﻟﺘﺠﻮﻳ ﺔ أواﻟﺘﻌﺮﻳ ﺔ )اﻟﻬ ﻮاء ﻳﺴ ﺒﺐ اﻟﺘﺄآﺴ ﺪ‬ (‫اﻟﺘﺄﺛﻴﺮ اﻻﺗﻼﻓﻲ ﻟﻠﺴﻴﺮ‬ 05-1

Asphalt Paving Mixture

Nov-2009


Affected by: • % of asphalt (‫)ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ‬ • Gradation (dense or open) (‫)اﻟﺘﺪرج‬ • Degree of compaction (‫)درﺟﺔ اﻟﺤﺪل‬ 3) Flexibility (‫)اﻟﻤﺮوﻧﺔ‬: (fatigue resistance) ability to bend repeatedly without fracture. (‫ ﻗﺎﺑﻠﻴﺔ اﻟﺘﻤﺪد ﻟﻤﺮات ﻣﺘﻌﺪدة ﺑﺪون ﺣﺪوث ﺗﻜﺴﺮ‬،‫)ﻣﻘﺎوﻣﺔ اﻟﻜﻠﻞ‬

4) Skid resistance (‫)ﻣﻘﺎوﻣﺔ اﻟﺘﺰﺣﻠﻖ‬: ability to provide safe coefficient of friction. (‫)أﻣﻜﺎﻧﻴﺔ ﺗﻮﻓﻴﺮ ﻣﻌﺎﻣﻞ اﺣﺘﻜﺎك ﺁﻣﻦ‬

Affected by: • % of asphalt. (‫)ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ‬ • Gradation. (‫)اﻟﺘﺪرج‬ 5) Imperviousness (‫)ﻋﺪم اﻟﻨﻔﺎذﻳﺔ‬: (‫)اﻻﻧﻐﻼﻗﻴﺔ أو ﻋﺪم وﺟﻮد ﻣﺴﺎﻣﺎت‬ 6) Workability (‫)ﻗﺎﺑﻠﻴ ﺔ اﻟﺘﺸ ﻐﻴﻞ‬: ability to provide smooth shaping of the finished pavement. Affected by: • Balanced portion of materials (‫)أﺟﺰاء ﻣﺘﻨﺎﺳﺒﺔ ﻣﻦ اﻟﻤﻮاد‬ • Efficient equipments.

Job Mix formula: 1. Selection of aggregate quality & gradation with in specification limits. (‫)اﺧﺘﻴﺎر اﻟﺮآﺎم ﻣﻦ اﻟﻨﺎﺣﻴﺔ اﻟﻨﻮﻋﻴﺔ واﻟﺘﺪرج ﺿﻤﻦ اﻟﻤﻮاﺻﻔﺎت اﻟﻘﻴﺎﺳﻴﺔ‬

2. Selection of asphalt cement grade. ((‫ وﻳﻜﻮن ﻟﻴﻦ ﻟﻀﻤﺎن ﻗﺎﺑﻠﻴﺔ اﻟﺘﺸﻐﻴﻞ واﻟﻤﻄﺎوﻋﺔ وﺻﻠﺐ ﻟﻤﻨﻊ اﻟﺘﺸﻮﻩ اﻟﺪاﺋﻤﻲ )اﻟﺜﺒﻮﺗﻴﺔ‬،‫)اﺧﺘﻴﺎر ﻧﻮﻋﻴﺔ اﻻﺳﻔﻠﺖ‬

3. Selection of optimum asphalt cement. (‫ ﺗﻜﻮن آﻤﻴﺔ آﺎﻓﻴﺔ ﻟﻀﻤﺎن اﻟﺪﻳﻤﻮﻣﺔ واﻟﻤﻄﺎوﻋﺔ وﻻ ﺗﺆﺛﺮ ﻋﻠﻰ اﻟﺜﺒﻮﺗﻴﺔ واﻻﺣﺘﻜﺎك اﻟﺪاﺧﻠﻲ‬،‫)اﺧﺘﻴﺎر ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ اﻟﻤﺜﻠﻰ‬

05-2


Nov-2009


Mix Design Methods: 1. Marshall method 2. Hveem method 3. Immersion – compression 4. Indirect tensile strength 5. Creep method

Marshall Method: (Max. size of aggregate 1") Stability: maximum load resistance of standard specimen (4" dia. & 2.5" height) when tested in the direction of diameter, at 60oC at the rate of 2"/min. (Stability ≥ 800 kg) (60oC) ‫( ﻋﻨ ﺪ ﺗﺴ ﻠﻴﻄﻪ ﺑﺎﺗﺠ ﺎﻩ اﻟﻘﻄ ﺮ وﺑﺪرﺟ ﺔ ﺣ ﺮارة‬4"x2.5") ‫ وهﻲ ﻣﻘﺎوﻣﺔ أآﺒﺮ ﺣﻤﻞ ﻣﺴﻠﻂ ﻋﻠﻰ ﻧﻤﻮذج ﻗﻴﺎﺳﻲ‬:‫ﺛﺒﺎﺗﻴﺔ ﻣﺎرﺷﺎل‬ (2"/min.) ‫وﺑﻤﻌﺪل ﺗﺤﻤﻴﻞ‬ ‫ ﻣﻠ ﺊ اﻟﻘﺎﻟ ﺐ ﺑ ﺎﻟﻤﺰﻳﺞ اﻟﺴ ﺎﺧﻦ ﺑﺪرﺟ ﺔ ﺣ ﺮارة اﻟﻤ ﺰج‬:‫ﻣﻠﺨ ﺺ ﻃﺮﻳﻘ ﺔ اﻟﻌﻤ ﻞ ﻟﻠﺘﺠﺮﺑ ﺔ‬ ‫( ﺛﻢ ﺗﺘﻢ ﻋﻤﻠﻴﺔ اﻟﺮص وذﻟﻚ ﺑﻤﻄﺮﻗﺔ‬100-105oC) ‫( ﺛﻢ ﺗﺮآﻬﺎ ﻟﺘﺒﺮد ﻟﺪرﺟﺔ‬160oC) Dial gage (1) Stability

Dial gage (2) Flexibility 4"

: ‫ﻗﻴﺎﺳﻴﺔ ﺑﻤﻌﺪل‬ 75 blow/end (tire pressure = 200psi) or 50 blow/end (tire pressure =100psi) ‫ ﺛ ﻢ ﺗﻔﺤ ﺺ‬،‫( ﻟﻀ ﻤﺎن زوال اﻟﺘﺸ ﻮهﺎت اﻟﻮﻗﺘﻴ ﺔ ﺑﺴ ﺒﺐ اﻟ ﺮص‬24hr) ‫ﺛ ﻢ ﺗﺘ ﺮك ﻟﻤ ﺪة‬ .‫ﺑﺠﻬﺎز ﻣﺎرﺷﺎل ﺑﺪرﺟﺔ ﺣﺮارة اﻟﻔﺤﺺ‬

Flexibility (Flow): the deformation (strain) corresponding to the max. load resistance of the standard specimen. (2 – 4 mm) Durability: density – voids analysis. % of air voids (3 – 5)% or (3 - 7)% in total mix.

05-3


Nov-2009

Lectures of Highway Engineering – Forth Stage Density (gm/m3)

‫ ﺛﺒﻮﺗﻴ ﺔ‬،‫ﺗﺮﺳﻢ اﻟﻌﻼﻗﺔ ﺑﻴﻦ ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ ﻓﻲ اﻟﻤﺰﻳﺞ ﻣﻊ اﻟﻌﻮاﻣﻞ )اﻟﻜﺜﺎﻓﺔ‬ .(‫ وﻧﺴﺒﺔ اﻟﻔﺠﻮات اﻟﻤﻤﻠﻮءة ﺑﺎﻻﺳﻔﻠﺖ‬،‫ ﻧﺴﺒﺔ اﻟﻔﺠﻮات‬،‫ اﻟﻤﺮوﻧﺔ‬،‫ﻣﺎرﺷﺎل‬

2

‫ﺛﻢ ﻳﺘﻢ اﺧﺘﻴﺎر اﻟﻨﺴﺒﺔ اﻟﻤﺜﻠﻰ ﻣﻦ اﻻﺳ ﻔﻠﺖ ﺑﺤﻴ ﺚ ﺗﺤﻘ ﻖ ﻗ ﻴﻢ ﻟﻬ ﺬﻩ اﻟﻌﻮاﻣ ﻞ‬

Stability (kg)

‫ وذﻟ ﻚ ﺑﺈﻳﺠ ﺎد ﻧﺴ ﺒﺔ‬.‫ﺿﻤﻦ اﻟﻤﻮاﺻﻔﺎت اﻟﻘﻴﺎﺳ ﻴﺔ ﻟﻄﺒﻘ ﺔ اﻟﺘﺒﻠ ﻴﻂ اﻟﻤﻄﻠﻮﺑ ﺔ‬ :‫اﻻﺳﻔﻠﺖ اﻟﻤﻘﺎﺑﻠﺔ ﻟﻤﺎ ﻳﺄﺗﻲ‬

Flow (mm)

(Max. Stability) ‫ أآﺒﺮ ﻗﻴﻤﺔ ﻟﻠﺜﺒﺎت‬.2 (‫( )ﻣﻌﺪل اﻟﻘﻴﻤﺔ‬5%) ‫ ﻋﻨﺪ ﻧﺴﺒﺔ ﻓﺠﻮات‬.3

5

1

(‫( )ﻣﻌﺪل اﻟﻘﻴﻤﺔ‬75%) ‫ ﻧﺴﺒﺔ اﻟﻔﺠﻮات ﻣﻤﻠﻮءة ﺑﺎﻻﺳﻔﻠﺖ‬.4

Voids in mix (%)

8

Voids filled with asphalt (%)

85

‫ ﻳﺴ ﻘﻂ اﻟﻤﻌ ﺪل ﻋﻠ ﻰ اﻟﻤﻨﺤﻨﻴ ﺎت‬،‫وﺑﺄﻳﺠ ﺎد ﻣﻌ ﺪل ﻟﻨﺴ ﺒﺔ اﻻﺳ ﻔﻠﺖ أﻋ ﻼﻩ‬ .‫ وﻳﺪﻗﻖ ﻣﻊ اﻟﻤﻮاﺻﻔﺔ‬،‫ﻻﻳﺠﺎد ﻗﻴﻤﺔ آﻞ ﻋﺎﻣﻞ ﻣﻦ اﻟﻌﻮاﻣﻞ‬ .‫وﺧﻮاص اﻟﺮآﺎم أو اﻻﺳﻔﻠﺖ‬

1000

600

(Max. Density) ‫ أآﺒﺮ ﻗﻴﻤﺔ ﻟﻠﻜﺜﺎﻓﺔ‬.1

‫إذا ﻟ ﻢ ﺗﻨﻄﺒ ﻖ أﺣ ﺪ اﻟﻤﻮاﺻ ﻔﺎت ﻓﻬﻨ ﺎك ﺧﻠ ﻞ ﻓ ﻲ ﻣﻮاﺻ ﻔﺎت وﺗﺤﻠﻴ ﻞ‬

2.4

2

65 4 5 6 Asphalt content by wt. of total mix (%)

For surface course (wearing): • % of asphalt (usually effective asphalt) = 4.5 – 6.5 % by wt. of total mix • Stability at 60oC & 75 blows/end ≥ 800 kg • Flow = 2 – 4 mm • % air voids in total mix = 3 – 5 % • % voids filled with asphalt = 70 – 85 % • % voids in mineral aggregate V. M. A.% (min. =15%) • Filler / Asphalt (max. = 1.4) • Index of retained strength = • Relative compaction =

comp. st. (Im mersion) *100% ≥ 70% comp. st. (Dry)

Field density *100% ≥ 96% Lab. density

Compaction of Pavement: a) Rolling edges & joints: immediately after spreading (Tandem steel roller). b) Break down rolling: as soon as the mix can bear roller (3-wheel roller). c) Intermediate roller: while the mix is still plastic (kinematics roller). d) Finish rolling: mix still warm to eliminate tire marks (steel roller). Note: Smoothness: (Irregularities) ≤ 3mm/3m 3m

05-4


Nov-2009


Analysis of Mixture (Mass-Volume Relationship): ‫ﻓﺮاﻏﺎت هﻮاﺋﻴﺔ‬ ‫اﻻﺳﻔﻠﺖ اﻟﻔﻌﺎل‬ (‫)اﻟﻤﺤﻴﻂ ﺑﺎﻟﺮآﺎم‬ Aggregate particle coated with asphalt, showing absorbed asphalt, permeable and impermeable porous

Zero

Air voids (air space)

Va

WS1

Binder (Asphalt) Effective asphalt Gb

VS1

WS2

Absorbed Asphalt

VS2

WS ‫اﻻﺳﻔﻠﺖ اﻟﻤﻤﺘﺺ داﺧﻞ اﻟﻤﺴﺎﻣﺎت اﻟﻨﻔﺎذة ﻟﻠﺮآﺎم‬ ‫اﻟﻔﺠﻮات اﻟﻤﺤﺼﻮرة ﺑﻴﻦ اﻟﺮآﺎم واﻻﺳﻔﻠﺖ‬ ‫اﻟﺠﺰء اﻟﺼﻠﺐ ﻣﻦ اﻟﺮآﺎم‬ + ‫اﻟﻔﺠﻮات اﻟﺪاﺧﻠﻴﺔ اﻟﺼﻤﺎء‬

W

Vv

V

Permeable Porous

Wagg.

Solid Aggregate + Impermeable Porous

V3 V2 V1

Aggregate coated with asphalt, showing air voids

Va = volume of air voids in total mix Vs1 = volume of effective asphalt Vs2 = volume of absorbed asphalt V1 = apparent volume of aggregate V2 = effective volume of aggregate V3 = bulk volume of aggregate V = total volume of mixture Vv = voids of aggregate (Voids in mineral aggregate)

- Bulk GA = bulk specific gravity of combined aggregate = =

WAgg. V3

100 %course %fine %filler + + Gs(course) Gs(file) Gs(filler)

Ex.: 50% (1"-No.4) Gs=2.6, 45%, 45% (No.4-No.200) Gs=2.65, 5% (No.200) Gs=3.15 Bulk GAgg. =

100 50 45 5 + + 2.6 2.65 3.15 05-5


Nov-2009


- PS = total % of asphalt (by wt. of total mix) - PA = % of aggregate (by wt. of total mix) PS + PA = 100% Æ PA = 100 - PS - In void less mix Æ max. theoretical sp. gr. of mix (max. Gm by testing in the lab (ASTM-2041) max . Gm =

- Effective GA = =

W V − Va WA V2

100 − PS (as sp. gr. of asphalt), where V2 = V-(Va+Vs1+Vs2), 100 PS − Gm Gs

Effective GA constant property (independent of asphalt content) ‫ وﻻﻳﺠ ﺎد‬،‫( ﻟﻨﺴ ﺒﺔ ﻣ ﻦ اﻻﺳ ﻔﻠﺖ ﻟﻨﻮﻋﻴ ﺔ رآ ﺎم واﺳ ﻔﻠﺖ‬Theoretical) (max. Gm) ‫ﻣ ﻦ ﺗﺠﺮﺑ ﺔ ﻣﺨﺘﺒﺮﻳ ﺔ ﻳﻤﻜ ﻦ أﻳﺠ ﺎد‬ (max. Gm) ‫( وﻧﻄﺒ ﻖ اﻟﻘ ﻮاﻧﻴﻦ اﻵﺗﻴ ﺔ ﻻﺳ ﺘﺨﺮاج ﻗ ﻴﻢ‬effective GA) ‫( ﻟﻨﺴ ﺐ أﺧ ﺮى ﻣ ﻦ اﻻﺳ ﻔﻠﺖ ﻳﻤﻜ ﻦ أﻳﺠ ﺎد‬max. Gm) .‫( دون إﺟﺮاء ﺗﺠﺎرب أﺧﺮى‬Calculated)

- Actual Gm =

W Wair = Wair − Wwater V

Found by: Core from pavement, or compacted sp. gr. in lab - Calculated max. Gm =

100 W = P 100 − PS V − Va S + Gs effective G A

- % air voids (in total mix) =

Va max . Gm − actual Gm *100% = *100% V max . Gm

- % voids in mineral aggregate (V.M.A.%) =

Vv actual Gm * PA *100% = 100 − bulk G A V

Vv = V – V3, WS1 + WS2 = WS, WS + WA = W

- Absorbed asphalt (% by wt. of agg.) = P'S2 = ⎡

1

1

WS 2 *100% WA

⎤

− =⎢ ⎥ * Gs *100% ⎣ bulk G A effective G A ⎦

V3 – V2 = VS2,

VS2Gs , WA

⎛ WA WA ⎞ ⎟⎟ ⎜⎜ , ⎝ V3 V2 ⎠

05-6


Nov-2009


- Effective asphalt (% by wt. of total mix) = PS1 = PS −

P'S2 *PA = PS – PS2 100

Where: PS2 = absorbed asphalt (% by wt. of total mix) - % voids filled with asphalt = =

VS1 *100% Vv

actual Gm * PS1 *100% actual Gm * PS1 + Gs * % air voids

Vv = Va + VS

Ex.: To prepare asphalt mixture as surface course, it is found the following: a) For aggregate: Sieve size: % passing: For course agg. Gs = 2.64 For fine agg.

Gs = 2.67

For filler

Gs = 3.10

1" 100

No. 4 45

No. 200 5

b) For asphalt (40-50) Æ Gs = 1.04 c) For asphalt concrete contains 5% asphalt Æ max. Gm = 2.49 If the same above materials used to construct asphalt concrete layer with 5.7% asphalt. The core from layer has Wair = 1200gm, & Wwater = 692gm. Check this layer? Sol.: Check: % air voids (3-5), V.M.A. = min. 15, asphalt voids (70-85), effective asphalt (4.5-6.5)%, ‫اﻟﺘﻘﺮﻳﺐ ﻟﺜﻼث ﻣﺮاﺗﺐ‬

Bulk GA =

100 = 2.672 55 40 5 + + 2.64 2.67 3.1

Effective GA =

100 − 5 = 2.687 (‫)ﻣﻘﺪرا ﺛﺎﺑﺖ ﺑﺘﻐﻴﺮ ﻧﺴﺒﺔ اﻻﺳﻔﻠﺖ‬ 100 5 − 2.49 1.04

For the layer with asphalt = 5.7% Actual Gm =

1200 = 2.362 1200 − 692 05-7


Nov-2009


Calculated max Gm =

100 = 2.464 5.7 100 − 5.7 + 1.04 2.687

Check: 1) % V. M. A. = 100 − 2) % air voids =

2.362 * 94.3 = 16.6% ≥ 15% ∴OK 2.672

2.464 − 2.362 *100% = 4.1% (3 – 5)% ∴OK 2.464

3) absorbed asphalt (by wt. of agg.) 1 1 ⎤ − = ⎡⎢ *1.04 *100% = 0.23% ⎣ 2.672 2.687 ⎥⎦

∴ effective asphalt concrete = PS1 = 5.7 −

0.23 * 94.3 = 5.48% (4.5-6.5)% ∴OK 100

4) % voids filled with asphalt =

2.362 * 5.48 *100% = 75.2% (70 – 85)% ∴OK 2.362 * 5.48 + 1.04 * 4.1

05-8


Nov-2009


06-Drainage: Proper drainage is important to ensure high quality pavement. Moisture in the subgrade and subbase layer can weaken these materials by: 1) Increasing pore water pressure. 2) Reducing the materials resistance to shear. - Some soils expand when moist causing differential heaving. - Moisture can cause stripping of aggregate.

Moisture Sources: Rain water, runoff, and high ground water, which prevented by: A) Surface Drainage: By removing all water that is present on surface and shoulder, by these primary means, to prevent water infiltration and accumulation: 1) Impermeable Mix: Air voids in total mix max. size of agg. * 2

Surface Leveling Base Subbase (C.B.R.) Subgrade (C.B.R.)

Where: a)

Wt18 = Equivalent (18kips) (≈8.2ton) single axle applications. Wt18 = f (axle type, axle load magnitude, ρt, design life, & SN) Wt18 = Σ T*A*F

Where: T = Future trucks / Day / Direction = (Future ADT * %Truck * D.D) A = Axle / Truck F = Damage factor b) ρt = Terminal Serviceability: Lowest serviceability allowed at the end of design period before resurfacing or reconstruction. By: Arbitrary scale (named present serviceability index: 5 for best riding quality, and 0 for worst) ρt = 2.5 for main highway ρt = 2.0 for secondary highway

08-1

Thickness Design of Flexible Pavement

Nov-2009


c) S = Road bed support value d) R = Regional factor e) SN = Structural number: Index number derived from analysis of traffic (Wt18), road bed support number (S), regional factor (R) [from monograph], which may be converted to thickness of various layers by using suitable layer coefficient. SN4 = a1 D1+a1' D2+a2 D3+a3 D4 SN3 = a1 D1+a1' D2+a2 D3 SN2 = a1 D1+a1' D2 SN1 = a1 D1 Surface Leveling Base Subbase Subgrade Subgrade

SN3 = a1 D1+a2 D2+a3 D3 SN2 = a1 D1+a2 D2 SN1 = a1 D1 D1 Æ a1 D2 Æ a1' D3 Æ a2 D4 Æ a3

Surface Base Subbase

D1 Æ a1 D2 Æ a2 D3 Æ a3

Subgrade Case (1) General

Case (2) Ideal Arrangement

(D1) ‫( ﻧﺠ ﺪ‬P.514) ‫( ﻣ ﻦ اﻟﻤﺨﻄ ﻂ‬a1)‫( و‬P.509) ‫( ﻣ ﻦ اﻟﻤﺨﻄﻄ ﺎت‬SN1) ‫( ﻧﺴﺘﺨﺮج‬D1) ‫( اﻟﻤﻄﻠﻮب‬SN1 = a1 D1) :‫ﻣﻼﺣﻈﺔ‬ .(0.5") ‫ﺑﺎﻻﻧﺞ وﻳﻘﺮب ﻷﻗﺮب ﻧﺼﻒ‬

For case (1) General: a1 = Layer coefficient for Surface

D1 = Thickness of Surface (inch)

a2 = Layer coefficient for Base

D2 = Thickness of Base (inch)

a3 = Layer coefficient for Subbase

D3 = Thickness of Subbase (inch)

Design monographs and tables: Yoder (Table 4.9 P.164, 165), (Fig. 15.1 P.509), (Table 15.1 P.510), (Fig. 15.3 P.514, 515), (Fig. 15.5 P.516)

08-2


Nov-2009


Ex.: A main rural highway has been built or designed for (200) daily 18-kips single axle load repetition. Regional factor (R) = 1.2 & the characteristics of pavement materials as following: Subgrade

Æ

C. B. R. = 5%

(Plastic clay)

Subbase

Æ

C. B. R. = 20%

(Sand-gravel)

Base

Æ

C. B. R. = 80%

(Crushed stone)

Surface

Æ

E = 4.3*105psi

(Asphalt concrete)

Sol.: From graph (P.514, 515) Surface

a1 = 0.42

(Modulus E = 4.3)

Base

a2 = 0.13

(C. B. R. = 80%)

Subbase

a3 = 0.095

(C. B. R. = 20%)

SN1 = a1 D1 Wt18 = 200 From graph (P.516) ‫( ﻟﻠﻄﺒﻘﺔ اﻟﺘﻲ ﻗﺒﻠﻬﺎ‬C. B. R.) ‫ﻗﻴﻢ‬

S1 (@ 80% C.B.R.) = 8.5

Æ

SN1 = 1.95

S2 (@ 20% C.B.R.) = 6.2

Æ

SN2 = 2.82

S3 (@ 5% C.B.R.) = 4

Æ

SN3 = 3.78

SN1 = a1 D1 1.95 = 0.42*D1

Æ

D1 = 4.64" use D1 = 5"

Æ

D2 = 5.54" use D2 = 6"

Æ

D3 = 9.47" use D3 = 9.5"

SN2 = a1 D1 + a2 D2 2.82 = 0.42*5 + 0.13*D2 SN3 = a1 D1 + a2 D2 + a3 D3 3.78 = 0.42*5 + 0.13*6 + 0.045*D3

08-3


Nov-2009


H.W.: Secondary highway, ADT (1994) = 400vph, truck = 40%, D. D. = 50%, annual rate of traffic growth = 6%, design life = 20 years, wet (saturated road bed). Truck type:

40Kips

13Kips

Materials

Properties

Asphalt concrete wearing course

M. S.

≥ 800 kg

Asphalt concrete leveling course

M. S.

≥ 700 kg

Crushed stone base

C. B. R.

80 %

Subbase

C. B. R.

30 %

Subgrade

C. B. R.

2%

Determine thickness of layers in (cm) Note: let D1 = 8 cm Ans.: D1 = 8cm (3"), D2 = 11cm (4.5"), D3 = 12cm (5"), D4 = 57cm (22.5") 1kg = 2.20462 lb

08-4


Nov-2009


(Yoder, Fig. 15.3, P.515) 08-5


Nov-2009


(Yoder, Fig. 15.3, P.515) 08-6


Nov-2009


Regional Factor (Yoder, Table 15.1, P.510) Condition Roadbed materials frozen to depth of 5in or more Roadbed materials dry, summer and fall Roadbed materials wet, spring thaw

R value 0.2 – 1.0 0.3 – 1.5 4.0 – 5.0

(Yoder, Fig. 15.5, P.516)

08-7


Nov-2009


(Yoder, Fig. 15.5, P.517)

08-8


Nov-2009


(Yoder, Fig. 15.1, P.509) 08-9


Nov-2009


Table 4.9 AASHO Equivalence Factors – Flexible Pavement (Yoder, P.164) Single Axle, ρt = 2.0 Axle Load (kips) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

1 0.0002 0.002 0.01 0.03 0.08 0.16 0.32 0.59 1.00 1.61 2.49 3.71 5.36 7.54 10.38 14.00 18.55 24.20 31.14 39.57

2 0.0002 0.003 0.01 0.04 0.08 0.18 0.34 0.60 1.00 1.59 2.44 3.62 5.21 7.31 10.03 13.51 17.87 23.30 29.95 38.02

Structural Number, SN 3 4 0.0002 0.0002 0.002 0.002 0.01 0.01 0.04 0.03 0.09 0.08 0.19 0.18 0.35 0.35 0.61 0.61 1.00 1.00 1.56 1.55 2.35 2.31 3.43 3.33 4.88 4.68 6.78 6.42 9.24 8.65 12.37 11.46 16.30 14.97 21.16 19.28 27.12 24.55 34.34 30.92

5 0.0002 0.002 0.01 0.03 0.08 0.17 0.34 0.60 1.00 1.57 2.35 3.40 4.77 6.52 8.73 11.48 14.87 19.02 24.03 30.04

6 0.0002 0.002 0.01 0.03 0.08 0.17 0.33 0.60 1.00 1.60 2.41 3.51 4.96 6.83 9.17 12.17 15.63 19.93 25.10 31.25

Tandem Axle, ρt = 2.0 Axle Load (kips) 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48

1 0.01 0.01 0.02 0.04 0.07 0.10 0.16 0.23 0.32 0.45 0.61 0.81 1.06 1.38 1.76 2.22 2.77 3.42 4.20 5.10

2 0.01 0.02 0.03 0.05 0.08 0.12 0.17 0.24 0.34 0.46 0.62 0.82 1.07 1.38 1.75 2.19 2.73 3.36 4.11 4.98


08-10

5 0.01 0.01 0.02 0.04 0.07 0.11 0.16 0.24 0.34 0.47 0.63 0.83 1.08 1.38 1.73 2.16 2.66 3.24 3.91 4.68

6 0.01 0.01 0.02 0.04 0.07 0.10 0.16 0.23 0.33 0.46 0.62 0.82 1.07 1.38 1.74 2.18 2.70 3.31 4.02 4.83


Nov-2009


Table 4.9 (Continued) (Yoder, P.165) Single Axle, ρt = 2.5 Axle Load (kips) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

1 0.0004 0.003 0.01 0.03 0.08 0.17 0.33 0.59 1.00 2.61 2.48 3.69 5.33 7.49 10.31 13.90 18.41 24.02 30.90 39.26

2 0.0004 0.004 0.02 0.05 0.10 0.20 0.36 0.61 1.00 1.57 2.38 3.49 4.99 6.98 9.55 12.82 16.94 22.04 28.30 35.89


5 0.0002 0.003 0.01 0.03 0.09 0.19 0.36 0.62 1.00 1.51 2.18 3.03 4.09 5.39 6.97 8.88 11.18 13.93 17.20 21.08

6 0.0002 0.002 0.01 0.03 0.08 0.18 0.34 0.61 1.00 1.55 2.30 3.27 4.48 5.98 7.79 9.95 12.51 15.50 18.98 23.04


1 0.01 0.02 0.03 0.04 0.07 0.11 0.16 0.23 0.33 0.45 0.61 0.81 1.06 1.38 1.75 2.21 2.76 3.41 4.18 5.08

2 0.01 0.02 0.04 0.07 0.10 0.14 0.20 0.27 0.37 0.49 0.65 0.84 1.08 1.38 1.73 2.16 2.67 3.27 3.98 4.80


08-11

5 0.01 0.01 0.03 0.05 0.08 0.12 0.18 0.26 0.36 0.50 0.66 0.86 1.09 1.38 1.70 2.08 2.51 3.00 3.55 4.17

6 0.01 0.01 0.02 0.04 0.07 0.11 0.17 0.24 0.34 0.47 0.63 0.83 1.08 1.38 1.73 2.14 2.61 3.16 3.79 4.49


Nov-2009


09-Rigid Pavement: Joints Concrete slab Concrete slab Base (or Subbase)

Function of Base (or Subbase): 1) Drainage purpose

Subgrade

2) Reduce the effect of subgrade volume change on concrete layer 3) Prevent pumping of fines through joints & edges 4) Increase "K" modulus of subgrade reaction

Rigid Pavement Characteristics: - Can resist unlimited loading - Minor defects are not reflected. - More skid resistance, safe. - More economical for same projects at certain location. - Concrete layer is less thickness than other layers.

Rigid Pavement Types: a) Plain concrete pavement: 1. No reinforcement except of using tie bars (for longitudinal joints) 2. Closer spacing between contractions joint (as transverse joints)

Longitudinal Joints Transverse Joints Inclined Joints

3. Inclined joints may be used (for better load transfer) 4. Very limited use b) Simply reinforced concrete pavement: 1. Temperature (wire-mesh, B. R. C.) reinforcement between joints to control cracking (close to the upper surface) 2. Dowel bars across transverse joints 09-1

Rigid Pavement

Nov-2009


3. Tie bars across longitudinal joints to control warping 4. Wider spacing between joints (from 3-6m to 12-14m)

Longitudinal Joints Transverse Joints

5. Widely used Section

c) Continuously reinforced concrete pavement: 1. No joints except some expansion joints & may be some contraction joints 2. Heavy reinforcement (≈ > 0.6% of cross sectional area) 3. High cost 4. Used in very-weak subgrade & high traffic load d) Pre-stressed concrete pavement: 1. Fewer joints 2. More expensive

Type of Joints in Rigid Pavement: 1) Contraction joints: to relieve excessive tensile stress due to drop in temperature. ‫ واﻟﻨﺎﺗﺠﺔ ﻣﻦ اﻻﺣﺘﻜﺎك ﺑ ﻴﻦ اﻟﺒﻼﻃ ﺔ‬،‫ ﻟﻠﺘﺨﻠﺺ ﻣﻦ اﺟﻬﺎدات اﻟﺸﺪ اﻟﻨﺎﺗﺠﺔ ﻣﻦ اﻧﺨﻔﺎض درﺟﺔ اﻟﺤﺮارة‬:‫ﻣﻔﺎﺻﻞ اﻟﺸﺪ‬ .‫ واﻟﺘﻲ ﺗﺴﺒﺐ ﻓﺸﻞ اﻟﻄﺒﻘﺔ‬،(Subgrade) ‫واﻟﺘﺮﺑﺔ ﺗﺤﺘﻬﺎ‬

‫ﺗﻘﻠﺺ‬ ‫ﻗﻮى اﺣﺘﻜﺎك‬

‫ واﻷﺧ ﺪود‬،‫ ﻟﻤﻨﻊ ﺗﺄآﺴﺪ ﺣﺪﻳﺪ اﻟﺘﺴﻠﻴﺢ وﺗﺄﺛﺮ ﻃﺒﻘﺔ اﻟﺘﺮﺑﺔ‬،‫وﺗﻌﺎﻟﺞ ﺑﻌﻤﻞ أﺧﺪود ﻳﻤﻸ ﺑﺎﻟﻤﺎﺳﺘﻚ ﻟﻤﻨﻊ اﻟﻤﻴﺎﻩ ﻣﻦ اﻟﻤﺮور‬ .‫ﻳﺼﻨﻊ ﻣﻨﻄﻘﺔ ﺿﻌﻴﻔﺔ ﻟﺘﺤﺪﻳﺪ ﻣﺴﺎر اﻟﻔﺸﻞ‬ 3/8"

B.R.C. d/4

d

d/2

Fixed

Dowel bars 1/2"-3/4" ϕ, 12-24" length, & 12-18" spacing (For load transfer)

Free

09-2

Rigid Pavement

Nov-2009


B. R. C. Design: ‫( ﻓ ﻲ اﻟﺠ ﺰء اﻷﻋﻠ ﻰ ﻣ ﻦ ﻃﺒﻘ ﺔ اﻟﺘﺒﻠ ﻴﻂ ﻟﻤﻘﺎوﻣ ﺔ اﺟﻬ ﺎدات اﻟﺸ ﺪ‬B.R.C.) ‫ﺗﻮﺿ ﻊ ﻃﺒﻘ ﺔ ﻣ ﻦ اﻟﺘﺴ ﻠﻴﺢ‬ ‫ وﺗﻜ ﻮن ﻟﻄﺒﻘ ﺔ اﻟﺘﺒﻠ ﻴﻂ ﺑ ﻴﻦ اﻟﻤﻔﺎﺻ ﻞ )ﻋﻠ ﻰ ﺟ ﺎﻧﺒﻲ‬،‫( اﻟﻤﺘﻮﻟﺪة ﺑﺴﺒﺐ ﺗﻐﻴﺮ ﺗﺪرﺟﺎت اﻟﺤ ﺮارة‬Tensile stresses) :‫ وأﺳﻠﻮب ﺣﺴﺎب آﻤﻴﺔ اﻟﺘﺴﻠﻴﺢ آﻤﺎ ﻳﺄﺗﻲ‬،(‫اﻷﺧﺪود‬ L Edge b

d joint

joint

Edge

1ft

C

L = Allowable spacing for contraction joint (for longitudinal reinforcement), (ft) b = Slab width, (ft) C = Coefficient of friction (1 – 2 use 1.5) γ = Unit wt. of concrete (pcf) d = Slab thickness (ft) Friction resistance = Allowable tensile strength Friction resistance = Concrete tensile strength + Steel tensile strength (L/2 * b * d)* γ * C = b * d * ftc + As * fs For one unit of width use b =1ft For safety assume concrete tensile strength (b * d * ftc) = 0 ftc = Allowable tensile strength of concrete ≈ 400 psi fs = Allowable tensile strength of steel ≈ 25000 psi As = Area of steel (in2/ft) W=d*γ where: W = Weight of 1ft2 of slab L/2 * 1 * W * C = As * fs As =

L*W *C 2FS

‫( ﺗﻜ ﻮن اﻟﻤﺴ ﺎﻓﺔ ﺑ ﻴﻦ‬L) ‫ أﻣ ﺎ ﻟﻠﺘﺴ ﻠﻴﺢ ﺑﺎﻻﺗﺠ ﺎﻩ اﻟﻌﺮﺿ ﻲ‬،‫( ﺗﻜﻮن اﻟﻤﺴﺎﻓﺔ ﺑﻴﻦ ﻣﻔﺼ ﻠﻴﻦ‬L) ‫ﻟﻠﺘﺴﻠﻴﺢ ﺑﺎﻻﺗﺠﺎﻩ اﻟﻄﻮﻟﻲ‬ .(b) ‫( أي‬edge to edge) ‫ﺣﺎﻓﺘﻲ اﻟﻄﺮﻳﻖ‬ 09-3

Rigid Pavement

Nov-2009


2) Expansion Joints: provide a clear spacing along the depth to relieve excessive compressive stresses due to rise in temperature. ‫ ﻓﺎﻟﻤﻌﺎﻟﺠﺔ ﺑﻌﻤﻞ أﺧﺪود أو ﻓﺮاغ ﻋﻠﻰ ﻋﻤﻖ ﻃﺒﻘ ﺔ اﻟﺘﺒﻠ ﻴﻂ ﻟﻤﻨ ﻊ‬،‫ ارﺗﻔﺎع درﺟﺔ اﻟﺤﺮارة ﺗﺴﺒﺐ اﻟﺘﻤﺪد‬:‫ﻣﻔﺎﺻﻞ اﻟﺘﻤﺪد‬ .‫إﺟﻬﺎدات اﻻﻧﻀﻐﺎط‬ 3/4" d/4 d

d/2

Fixed

Free

Dowel bar

- Difficult in construction & maintenance - Needed when casting in cold season, near structure, & for materials with high coefficient of thermal expansion - Contraction joints used as expansion joints 3) Warping joints: to relieve tensile stresses due to warping because of difference in temperature between top and bottom of the slab (in night & day). 3/8"

T

Keyed

C

d/4 d

d/2

Fixed

Tie bar 1/2"ϕ, 30-36" length, & 24-30" spacing

Fixed

Night C T Day

4) Construction joints: in some conditions. .(‫ وﻳﺴﺘﺨﺪم ﻓﻲ ﺑﻌﺾ اﻟﺤﺎﻻت )ﻣﺜﻞ ﻧﻬﺎﻳﺔ وﺟﺒﺔ ﻋﻤﻞ وﺑﺪاﻳﺔ وﺟﺒﺔ أﺧﺮى‬:‫ﻣﻔﺼﻞ إﻧﺸﺎﺋﻲ‬ Fixed

Free

09-4

Rigid Pavement

Nov-2009


Thickness Design of Rigid Pavement: Design methods: 1) PCA method (Portland Cement Association) 2) AASHO (AASHTO) guide method 1) PCA method: depends on fatigue analysis under repeated loading. h = f (axle type, axle load magnitude, No. of repetitions, M. R. (fr), & K) where: h = thickness of concrete layer Design steps: a) Analysis of traffic: Nact.: Actual No. of repetitions in 40-years period for each axle load. Axles ≥ 16 kips – Single (‫ وﻣﻔﺮدة ﺗﻬﻤﻞ‬16 ‫)اﻟﻤﺤﺎور أﻗﻞ ﻣﻦ‬ Axles ≥ 30 kips – Tandem (‫ وﻣﺰدوﺟﺔ ﺗﻬﻤﻞ‬30 ‫)اﻟﻤﺤﺎور أﻗﻞ ﻣﻦ‬ Nact. = T * A * 40 * 365 Where: T = Future truck per day per direction A = No. of axles per truck for certain axle load b) Correction for impact: Static axle load * 1.2 = corrected (dynamic) axle load c) M. R. (fr): Modulus of rupture (for third-point loading) (psi) σ=

M.C I

P

Where: M=

b d

b.d 3 P.L d , C= , I= 6 2 12 P.L ∴ M.R. = 2 b.d

L/3

09-5

L/3

L/3

Rigid Pavement

Nov-2009


M.R. = 8 − 10 f c

= 600 – 750 psi Where: fc = Compression strength of concrete (psi) d) K: Modulus of subgrade reaction e) S: Actual load stress in pavement Determine form design charts from either single or tandem axle, depend on: - Corrected axle load - K – value - Suggested thickness of concrete layer "d" f) SR: Stress ratio SR =

S , for each axle load M.R.

g) Nall.: Allowable No. of repetitions of each axle load to account for fatigue in concrete pavement (depend on stress ratio SR) Note: Unlimited repetitions for SR = 0.5 or less Æ ∞ vehicles h) F: Fatigue percentage F=

N act. *100% , for each axle load N all.

i) Σ F < 100%, for correct assumption of "d" value .‫" وإﻋﺎدة اﻟﺘﺼﻤﻴﻢ‬d" ‫( ﻓﻴﺠﺐ ﺗﻜﺒﻴﺮ‬ΣF ≥ 100%) ‫إذا آﺎﻧﺖ‬ ،"d" ‫( ﻓﺘﺒﻘﻰ‬ΣF ≤ 85%) ‫إذا آﺎﻧﺖ‬ .‫( وإﻋﺎدة اﻟﺘﺼﻤﻴﻢ‬1-0.5") ‫" ﺑﻤﻘﺪار‬d" ‫( ﻓﺎﻟﺘﺼﻤﻴﻢ ﻏﻴﺮ اﻗﺘﺼﺎدي أي ﻧﻘﻠﻞ‬85%) ‫أﻣﺎ إذا آﺎﻧﺖ أﻗﻞ ﻣﻦ‬ Design monographs and tables: Yoder (Fig. 17.2, 17.3, P.604, 605), (Table 17.1, P.603)

09-6

Rigid Pavement

Nov-2009


Ex.: T = 60 trucks/day/dir, K = 150 psi, & M. R. = 650 psi Axle type

Axle load A' (kips) (No. of axles/100 trucks) Tandem 45 0.1 43 0.1 41 0.1 39 1.0 37 0.9 35 1.4 33 1.8 31 9.4 Single 21 3.2 19 5.4 17 6.1 Find concrete layer thickness "d" using P.C.A. method?

Sol.: Nact. = 60*(A'/100)*40*365

…(1)

Corrected axle load = 1.2*axle load

…(2)

…(3)

S 650 N act. F= *100% N all.

SR =

…(4)

Assume d = 7" (1) Axle type

(2) Axle load

Tandem

45 43 41 39 37 35 33 31 21 19 17

Single

(3) A' (No. of axles/ 100 trucks) 0.1 0.1 0.1 1.0 0.9 1.4 1.8 9.4 3.2 5.4 6.1

(4) Nact. (3)+eq.(1) 876 876 876 8760 7884 12250 15800 82400 28100 47400 53500

(5) Corrected axle load (2)+eq.(2) 54 51.6 49.2 46.8 44.4 42.8 39.6 37.6 25.2 22.8 20.1

(6) S

(7) SR

(8) Nall.

(9) F (%)

Graph+(5)+K+d 435 415 410 390 375 350 325 310 350 325 290

(6)+eq.(3) 0.67 0.64 0.63 0.60 0.58 0.54 0.50 0.48 0.54 0.50 0.45

(7)+table 4500 11000 14000 32000 57000 180000 ∞ ∞ 180000 ∞ ∞ ΣF

(4)+(8)+eq.(4) 19 8 6 27 14 7 0 0 15 0 0 96%

ΣF(%) = 96% < 100% ∴ d = 7" OK

09-7

Rigid Pavement

Nov-2009


2) AASHTO method: d (slab thickness) = f (ρt, No. of Wt18, K, & working stresses in concrete) a) ρt: Terminal level of serviceability 2.5 for main highway 2.0 for secondary highway b) No. of Wt18: No. repetitions of 18-kips single axle load as: Wt18 = f (axle type, effective axle load, ρt, design life, assumed "d") c) K: Modulus of subgrade reaction (pci) d) Working stress in concrete = M. R. * 0.75 ‫( ﻣﻦ اﻟﻤﻔﺮوض ﺗﻌﺎد ﻋﻤﻠﻴﺔ اﻟﺘﺼﻤﻴﻢ‬0.5") ‫ اﻟﻤﺴﺘﺨﺮﺟﺔ ﺑﻤﻘﺪار أﻗﻞ أو أآﺒﺮ ﻣﻦ‬d ‫إذا آﺎﻧﺖ‬ Design monographs and tables: Yoder (Fig. 17.4, 17.5, P.608), (Table 4.10, P.166, 167)

Ex.: T = 60 trucks/day/dir, K = 150 psi, & M. R. = 650 psi Axle type

Axle load A' (kips) (No. of axles/100 trucks) Tandem 45 0.1 43 0.1 41 0.1 39 1.0 37 0.9 35 1.4 33 1.8 31 9.4 Single 21 3.2 19 5.4 17 6.1 Find concrete layer thickness "d" using AASHTO method? (assume ρt = 2.5)

09-8

Rigid Pavement

Nov-2009


Sol.: Nact. = 60*(A'/100)*40*365

…(1)

Corrected axle load = 1.2*axle load

…(2)

Assume d = 7"

(1) Axle type

(2) Axle load

Tandem

45 43 41 39 37 35 33 31 21 19 17

Single

(3) A' (No. of axles/ 100 trucks) 0.1 0.1 0.1 1.0 0.9 1.4 1.8 9.4 3.2 5.4 6.1

(4) Nact. (3)+eq.(1)

(5) Corrected axle load (2)+eq.(2)

(6) Equivalent factor (5)+Table

(7) No. of Wt18 (4)*(6)

876 876 876 8760 7884 12250 15800 82400 28100 47400 53500

54 51.6 49.2 46.8 44.4 42.8 39.6 37.6 25.2 22.8 20.1

10.61 9.23 7.85 6.47 5.21 4.16 3.296 2.588 3.796 2.56 1.65 ΣWt18

9294.4 8085.5 6876.6 56677.2 41075.6 50960 52076.8 213251.2 10666.6 12134.0 88596 559694 psi

ΣWt18 ≈ 560 ksi Working stress = 0.75 * 650 = 487.5 psi & K = 150 psi From monograph: d = 6.25" < dassumed (with more than 0.5") Not OK check (redesign) with d = 6.5"

09-9

Rigid Pavement

Nov-2009


Table 17.1. Stress Ratios Allowable Load Repetitions Yoder, P.603

Stress Allowable Ratio Repetition SR Nall (Veh.) 0.51 400,000 0.52 300,000 0.53 240,000 0.54 180,000 0.55 130,000 0.56 100,000 0.57 75,000 0.58 57,000 0.59 42,000 0.60 32,000 0.61 24,000 0.62 18,000 0.63 14,000 0.64 11,000 0.65 8,000 0.66 6,000 0.67 4,500 0.68 3,500 0.69 2,500 0.70 2,000 0.71 1,500 0.72 1,100 0.73 850 0.74 650 0.75 490 0.76 360 0.77 270 0.78 210 0.79 160 0.80 120 0.81 90 0.82 70 0.83 50 0.84 40 0.85 30 NOTE: Unlimited Repetition for SR = 0.5 or less

Figure 17.2, Yoder, P.604

d = (7 – 9) in

Charts and Tables for Rigid Pavement Thickness Design by PCA Method

Figure 17.3, Yoder, P.605

09-10

Rigid Pavement

Nov-2009


Table 4.10 AASHO Equivalence Factors – Rigid Pavement (Yoder, P.166) Single Axle, ρt = 2.0 Axle Load (kips) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

6 0.0002 0.002 0.01 0.03 0.09 0.19 0.35 0.61 1.00 1.55 2.32 3.37 4.76 6.59 8.92 11.87 15.55 20.07 25.56 32.18

7 0.0002 0.002 0.01 0.03 0.08 0.18 0.35 0.61 1.00 1.56 2.32 3.34 4.69 6.44 8.68 11.49 15.00 19.30 24.54 30.85

D – Slab Thickness (in) 8 9 0.0002 0.0002 0.002 0.002 0.01 0.01 0.03 0.03 0.08 0.08 0.18 0.18 0.34 0.34 0.60 0.60 1.00 1.00 1.57 1.58 2.35 2.38 3.40 3.47 4.77 4.88 6.52 6.70 8.74 8.98 11.51 11.82 14.95 15.30 19.16 19.53 24.26 24.63 30.41 30.75

10 0.0002 0.002 0.01 0.03 0.08 0.17 0.34 0.60 1.00 1.58 2.40 3.51 4.97 6.85 9.23 12.17 15.78 20.14 25.36 31.58

11 0.0002 0.002 0.01 0.03 0.08 0.17 0.34 0.60 1.00 1.59 2.41 3.53 5.02 6.94 9.39 12.44 16.18 20.71 26.14 32.57

10 0.01 0.03 0.05 0.08 0.13 0.20 0.30 0.44 0.62 0.85 1.14 1.51 1.96 2.51 3.17 3.95 4.87 5.95 7.20 8.63

11 0.01 0.03 0.05 0.08 0.13 0.20 0.30 0.44 0.62 0.85 1.14 1.51 1.97 2.52 3.19 3.98 4.93 6.03 7.31 8.79


6 0.01 0.03 0.05 0.09 0.14 0.22 0.32 0.45 0.63 0.85 1.13 1.48 1.91 2.42 3.04 3.79 4.67 5.72 6.94 8.36

7 0.01 0.03 0.05 0.08 0.14 0.21 0.31 0.45 0.64 0.85 1.13 1.45 1.90 2.41 3.02 3.74 4.59 5.59 6.76 8.12


09-11

Rigid Pavement

Nov-2009


Table 4.10 (Continued) (Yoder, P.167) Single Axle, ρt = 2.5 Axle Load (kips) 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40

6 0.0002 0.003 0.01 0.04 0.10 0.20 0.38 0.63 1.00 1.51 2.21 3.16 4.41 6.05 8.16 10.81 14.12 18.20 23.15 29.11

7 0.0002 0.002 0.01 0.04 0.09 0.19 0.36 0.62 1.00 1.52 2.20 3.10 4.26 5.76 7.67 10.06 13.04 16.69 21.14 26.49


10 0.0002 0.002 0.01 0.03 0.08 0.18 0.34 0.60 1.00 1.58 2.38 3.45 4.85 6.61 8.79 11.43 14.59 18.33 22.74 27.91

11 0.0002 0.002 0.01 0.03 0.08 0.17 0.34 0.60 1.00 1.58 2.40 3.50 4.95 6.81 9.14 11.99 15.43 19.52 24.31 29.90

10 0.01 0.03 0.05 0.08 0.13 0.20 0.30 0.44 0.62 0.85 1.14 1.50 1.95 2.48 3.12 3.87 4.74 5.75 6.90 8.21

11 0.01 0.03 0.05 0.08 0.13 0.20 0.30 0.44 0.62 0.85 1.14 1.51 1.96 2.51 3.16 3.94 4.86 5.92 7.14 8.55


6 0.01 0.03 0.06 0.10 0.16 0.23 0.34 0.48 0.64 0.85 1.11 1.43 1.82 2.29 2.85 3.52 4.32 5.26 6.36 7.64

7 0.01 0.03 0.05 0.09 0.14 0.22 0.32 0.46 0.64 0.85 1.12 1.44 1.82 2.27 2.80 3.42 4.16 5.01 6.01 7.16


09-12

Rigid Pavement

Nov-2009


09-13

Rigid Pavement

Apr-10


10-The Effect of type and amount of Filler on Asphalt Paving Mix First: The role of the filler in the mix is very complex: 1. Serves as an inertic materials in the mix. 2. Serves as an active materials in the mix. (due to its fineness and surface characteristics). a. Specific Surface (S.S.) (m2/kg). b. Surface Activity (S.A.) (Shape Factor). c. Absorption. * F/A (filler/Asphalt) ratio should be decreased as S.S. increases. * S.A.: Capacity of filler particles to absorb AC. And it increases as the irregularity increases (roughness and angularity) * More absorption è decrease in free AC.

Second: 1. Behavior of filler/AC (mastic) and asphalt paving mixture can be explained by physical-chemical properties of filler at the filler-AC interface. 2. H.L. (Hydrated Lime) have the highest geometric irregularity and high surface activity è higher consistency (low penetration, high softening point, low ductility) for mastics and higher strength in mix. 3. Rapid deterioration of mix occurred with non-active filler (after 4 days of immersion at 60oC water) and H.L.

Exhibits a superior durability potential with mix sensitivity to the immersion periods (as an active filler). [by E. Marshall St. Loss%, H.L. 5%, LSD (Limestone Dust) (15%)]

4. The use of Portland cement as filler increase the fatigue life of the mix.

10-1

The Effect of type and amount of Filler on Asphalt Paving Mix

Apr-10


Third: 1. The type and amount of filler used in asphalt paving mix is are of the most important factor that influence distress. (permanent deformation, low temp. cracking, fatigue cracking, and moisture damage).

2. Limestone dust (L.D.) (3, 5, 7)%, Hydrated Lime (H.L.) (5%), Cement (C.I.) (5%).

- Marshall Stiffness = Stability / Flow (kg/mm) (Sp. 4"x2.5") - Compressive Strength = Max load / Cross-Section Area (kg/cm2) (Sp. 4"x4") - Indirect tensile strength =

2. Pu (kg/cm2) π.t.D

3. There is an optimum filler content for every type, satisfying most of asphalt paving mixture requirements for (strength, durability, workability).

Shape Factor = 2.30 à

H.L. (sp=2.30) à S.S. = 750m2/kg

Shape Factor = 1.30 à

L.D. (sp=2.88) à S.S. = 260m2/kg C.I. (sp=3.10)

10-2



10-3

Apr-10


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