1. CLASSIFICATION OF ROAD MATERIALS AND IDENTIFICATION OF INDEGINOUS QUARRIES CPD SEMINAR ON CLASSIFICATION OF ROAD MATERIALS AND IDENTIFICATION OF INDEGINOUS QUARRIES Engr. Zahid Arif, Secretary C&W Department December 11, 2012 By

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3. SEQUENCE OF PRESENTATION  INTRODUCTION  IMPORTANCE OF THE SUBJECT  SOIL CLASSIFICATION  SPECIFIED PARAMETERS OF SUB BASE & BASE MATERIALS  IDENTIFICATION OF INDEGINOUS QUARRIES  QUESTION & ANSWER SESSION 3

4. IMPORTANCE OF THE SUBJECT  Selection of specified materials through:  Visual inspection  Laboratory tests  Economizing the construction cost  Identification of local quarries  Effective supervision and monitoring of developmental projects  Selection of suitable site for Building projects

6. SOIL CLASSIFICATION SOIL CLASSIFICATION

7. SOIL CLASSIFICATION  Soil is defined as a conglomeration consisting of a wide range of relatively smaller particles derived from a parent rock through mechanical weathering processes of water abrasion, freeze-thaw cycles, temperature changes, and chemical weathering processes like oxidation and carbonation. The density of soil mass can range from very hard to very soft.  Classification is the laboratory-based process of grouping soils with similar engineering characteristics into various categories.  The AASHTO system (M 145) is commonly used for grouping of soils into various categories having similar load carrying capacity for subgrade design of highway projects.

8. Engineering Classification of Soils Cassagrande apparatus

9. Wentworth Scale “Gravel” 75-2 mm “Sand” 2-0.075 mm “Silt and Clay” < 0.075 mm “Cobbles” 75 – 300 mm ( 3 in – 12 in) Particle Size Definitions “Boulders” > 300mm (>12 inches)

10. 10 Grain Size definitions Boulders Cobbles GravelSandSilt and Clay CoarseFineCoarseFineMedium 300 mm 75 mm 19 mm (No.4) 4.75 mm (No.10) 2.0 mm (No.40) 0.425 mm (No.200) 0.075 mm

11. Parameters of Soil Classification For grouping of Soil in various categories, the following soil characteristics are required to be determined first:  Liquid Limit  Plastic Limit  Plasticity Index (PI) As water content increases, the shear strength of soil decreases.

12. Status changes with the increase in Water Content

13. Liquid Limit  Soil is practically a liquid in this state  Shows minimal shear strength  Defined as the moisture content required to close a distance of 0.5 inch along the bottom of a groove after 25 blows of the liquid limit device.

14. Plastic Limit  Water content at which the soil becomes plastic  Less water content than liquid limit  Wide range of shear strengths at plastic limit  Defined as the moisture content at which the soil begins to crumble when rolled into 1/8” dia threads

15. Plasticity Index (PI)  Difference between Liquid Limit and Plastic Limit  Important measure of plastic behavior Example: Liquid Limit = 24% Plastic Limit 14 % Plasticity Index = 24 – 14 = 10 % In general…. PIDegree of Plasticity 0Non-plastic 1-5Slightly plastic 5-10Low plasticity 10-20Medium plasticity 20-40High plasticity 40+Very high plasticity

16. Procedure for AASHTO Classification Developed in 1929 as the Public Road Administration Classification System modified by the Highway Research Board (1945)

17. COARSE-GRAINED SOIL (Sand & Gravel) STEPS  Determine the percentage of soil passing the #200 sieve  Determine the percent passing the #10 and #40 sieves for Sub grouping.  Determine the liquid limit and plasticity index  THEN, determine soil group or subgroup from Table - 1

18. For coarse-grained soils (gravel and sand), determine the percent passing #10, #40, and #200 sieves. Cobble Gravel Very Coarse to Medium Sand Fine/Very Fine Sand Silt/Clay 3 in #10 #40 #200 #10 #40 #200

19. 19 Table-1 : AASHTO Classification for Coarse-grained Soil

20. FINE-GRAINED SOIL (Silt & Clay) STEPS  Determine the percentage of soil passing the #200 sieve  Determine the liquid limit and plasticity index  THEN, determine soil group or subgroup from Table - 2

21. 21 Table-2 : AASHTO Classification for Fine-grained Soil

22.  To evaluate the quality of a soil as a highway subgrade material, a number called the group index (GI) is also incorporated alongwith the groups and subgroups of the soil.  The group index is written in parenthesis after the group or subgroup designation.  GI is given by the following general Equation:  GI = (F-35)[0.2+0.005(LL-40)] + 0.01(F-15) (PI-10)  Group Index usually reflects the relative strength of material, where low values have greater shear strength GROUP INDEX e.g: A-7-5(9)

23. Determination of Group Index

24. Example Problem Examples

25. Solution

26.  SOFT ROCK The rock which can be cut by the blade of a 200 HP Bull Dozer is classified as a Soft Rock.  MEDIUM ROCK The rock which cannot be cut by the blade of a 200 HP Bull Dozer is classified as a Medium Rock.  HARD ROCK The rock which cannot be cut by the Ripper of a 200 HP Bull Dozer is classified as a Hard Rock. Engineering Classification of Rocks

27. SUB BASE “SUB BASE is the structural layer of road pavement consisting of NATURAL or processed aggregates placed above the Sub grade” The material should comply with the following quality requirements: 27

28. 28 MATERIAL REQUIREMENTS FOR SUB BASE MATERIALS GRADING REQUIREMENTS US STANDARD SEIVE SIZEPERCENT PASSING CLASS ACLASS B 2½”100- 2”90-100100 1”50-8055-85 ⅜”⅜” -40-70 No. 435-7030-60 No. 10-20-50 No. 40-10-30 No. 2002-85-15 QUALITY PARAMETERS (i ) CBR value @ 98% Compaction >50 % (ii) Los Angles Abrasion Value < 50 % (iii) Liquid Limit < 25 (iv) Plasticity Index < 6 (v) Oversize < 5 % (vi) Sand Equivalent = 25 min 28

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30. AGGREGATE BASE COURSE “AGGREGATE BASE COURSE is the basic structural layer of flexible pavement consisting of a mixture of various sizes of crushed Aggregates ranging from 2” to material passing sieve #200” The material should fulfill the following suitability parameters: 30

31. 31 MATERIAL REQUIREMENTS FOR AGGREGATE BASE COURSE GRADING REQUIREMENT US STANDARD SEIVE SIZEPERCENT PASSING CLASS ACLASS B 2”100 1”60-8075-95 ⅜”30-6540-75 No. 425-5530-60 No. 1015-4020-50 No. 408-2012-25 No. 2002-85-10 PHYSICAL PROPERTIES AND QUALITY PARAMETERS i. Los Angles Abrasion Value < 40 % ii. SOUNDNESS with NA 2 SO 4 <12 % iii. SAND EQUIVALENT < 45 % iv. L.L = 25 % (Max) v. P.I = 6% (Max) vi. CBR at 100 % compaction > 80 % vii. Laminated Particles <15% (By Volume) viii. Round particles < 10 % 31

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34. WATER BOUND MACADAM BASE  WBM is the base layer consisting of clean crushed stone mechanically interlocked by rolling and voids filled with mechanically interlocked by rolling and voids filled with screening materials with assistance of water. screening materials with assistance of water.  Fine aggregate (also called chocked materials) consists of crushed stone screenings free from clay lumps with specified crushed stone screenings free from clay lumps with specified gradation. gradation.  Following are the quality requirements of WBM and screening materials : materials : 34

35. GRADING REQUIREMENT US STANDARD SEIVE SIZE PERCENT PASSING CLASS ACLASS BCLASS C 4”100-- 3½”90-100-- 3”-100- 2½”25-6090-100100 2”-25-7590-100 1½”0-15 35-70 1”--0-15 3/4 in0-5 1/2 in--- FILLER MATERIAL OR SCREENINGS : Physical Requirements of Coarse Aggregate SIZE % Passing 3/8” (9.5mm) 100 Los Angles Abrasion value = Max 45% No. 4 (4.75 mm) 85-100 L.L = 25 % (Max) No. 100 (0.15 mm) 10-30 P.I = 6 (Max) CBR >80% Flakiness Index = Max 15% Soundness with (Na 2 SO 4 ) = Max 45% MATERIAL REQUIREMENTS FOR WBM 35

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37. 37 IDENTIFICATION OF INDIGENIOUS QUARRIES Based on the above characteristics, the following local quarries have been identified for road materials on various District level:  Baisai (Peshawar) for aggregate and WBM  Zangali Khwar(Peshawar) for Sub Base material  Nizampur and Lawrencepur for Coarse Sand  Watarh nullah (Nowshera) for Sub Base material  Palai (Malakand Agency) for aggregate and WBM  Khyali River bed material for filter layers and Granular backfill  Pir Sabaq (Nowshera) for aggregate and WBM  Sawal Dhair(Mardan) for aggregate and WBM  Pizzu (Sarai Naurang) for aggregate and WBM  Kurram River bed material(Bannu) for filter, Base & Sub Base.  Margalla (Islamabad) for aggregate and WBM.

38. THANK YOU 38