Compaction and Stabilization Equipment Chapter 5 Compaction and Stabilization Equipment Copyright © The McGraw-Hill Companies, Inc. Permission required for reproduction or display.

1912 Case steam roller COMPACTION

ROLLERS

COMPACTION The engineering properties of most soils can be improved by compaction. Compaction is the art of mechanically densifying materials.

COMPACTION The engineering properties improved by compaction. Load bearing capacity Control of shrinkage and swelling Reduced permeability

COMPACTION Soil gradation Moisture content Compactive effort The three major factors influencing soil density are: Soil gradation Moisture content Compactive effort

COMPACTION SPECIFICATIONS Must work in the box. 123.5 COMPACTION SPECIFICATIONS

COMPACTION Disking to dry the soil. The amount of water present in a soil mass affects the compaction operations and achievable soil density. Disking to dry the soil.

COMPACTION The most common methods of reducing soil moisture are by using the scarifying teeth on a grader or by disking.

COMPACTION May have to add water.

ADDING WATER But this depends on wind, temperature, and soil type. Normally, it is good practice to adjust water content to OMC = 2%. But this depends on wind, temperature, and soil type.

Use the figure: The OMC is ______? The Maximum dry density is ______?

COMPACTION OMC is 15%

COMPACTION Maximum dry density 120

COMPACTION Lift. A layer of soil placed on top of soil previously placed in an embankment. The term can be used in reference to material as spread or as compacted.

COMPACTION

SOIL TYPES SMALL GRAINED  #200 MESH SIEVE COHESIVE NON-COHESIVE

COMPACTION Effective roller capability soil ranges.

COMPACTION Static weight (pressure) Impact (sharp blow) Densification is accomplished by: Static weight (pressure) Impact (sharp blow)

COMPACTION Vibration (shaking) Kneading (manipulation) Densification is accomplished by: Vibration (shaking) Kneading (manipulation)

STATIC WEIGHT

TAMPING FOOT COMPACTOR Static weight & Kneading Leveling blade

PAD CONFIGURATION Pad foot Tamping foot

TAMPING FOOT COMPACTOR It is suitable for compacting all fined-grained soils, but is generally not suitable for use on cohesionless granular soils.

TAMPING FOOT COMPACTOR This roller compacts the soil from the bottom of the lift to the top. Lift thickness is generally limited to 8 in. compacted depth.

TAMPING FOOT COMPACTOR This type roller does not adequately compact the upper 2 to 3 in. of a lift. Therefore, for the last lift it should be followed with a pneumatic or smooth-drum roller.

TAMPING FOOT COMPACTOR Working in tandem

SHEEPS FOOT ROLLER

IMPACTOR

PNEUMATIC 4 5

PNEUMATIC Front and rear tire paths overlap.

PNEUMATIC All-wheel oscillation.

PNEUMATIC COMPACTOR Pneumatic-tired (rubber-tired) rollers are suitable for compacting most granular soils. They are not effective in compacting fine-grained clays. They compact by static-load and kneading action.

HEAVY PNEUMATIC COMPACTOR Heavy pneumatic rollers are capable of compacting soils to depths up to 18 in.

HEAVY PNEUMATIC 50 Ton proof roller

VIBRATORY SOIL COMPACTOR Single smooth drum

SINGLE SMOOTH DRUM VIBRATORY COMPACTOR This roller uses vibratory action in conjunction with ballast weight of the drum to compact.

SINGLE SMOOTH DRUM VIBRATORY COMPACTOR One of the most effective means of attaining density for cohesionless materials. It is a relatively light roller, therefore maximum loose-lift depth is 9 in.

SINGLE PADDED DRUM VIBRATORY COMPACTOR

DOUBLE DRUM VIBRATORY COMPACTOR

DOUBLE DRUM VIBRATORY COMPACTOR Use this roller to compact cohesionless subgrade, base courses, wearing surfaces, and asphalt.

DOUBLE DRUM VIBRATORY COMPACTOR Because it compacts from the top down, only relatively shallow lifts (less than 4 inches) can be worked.

COMPACTOR SPEEDS Sheepsfoot, crawler towed 3-5 Tamping foot Speed (MPH) Sheepsfoot, crawler towed 3-5 Tamping foot First 3 passes 3-5 Walking out 8-10 Multitired pneumatic 5-15 Smooth-drum vibratory 2-4 Padded-drum vibratory 2-4

COMPACTION EXERCISE Scrapers will deliver to the project 600 lcy per hr of fill material (dry clay). A self-propelled tamping foot roller will be used to compact the fill. (Rolling width is 84 in.)

COMPACTION EXERCISE Test strip compaction information indicates that 14 passes at 3 mph are required to obtain the required density. The fill material will be placed in 8 inch compacted lifts.

COMPACTION EXERCISE Based on this information determine the number of rollers required to support the scraper operation.

COMPACTION EXERCISE STEP 1: COMPACTION REQUIREMENTS Width of roller = 84 inches Speed = 3 mph Compacted lift thickness = 8 in. Number of passes required = 9

COMPACTION EXERCISE STEP 2: PRODUCTION CALCULATION Equ. 5.1, p. 128 Compacted cubic yards per hr =

COMPACTION EXERCISE W is compacted width in feet Where W is compacted width in feet S is average roller speed in MPH L is compacted lift thickness in inches

COMPACTION EXERCISE STEP 2: PRODUCTION CALCULATION Compacted cubic yards/hr =

COMPACTION EXERCISE STEP 2: PRODUCTION CALCULATION = 304 ccy/hr

COMPACTION EXERCISE STEP 3: EFFICIENCY FACTOR A 50 min working hour should be possible. Efficiency Factor of 0.83

COMPACTION EXERCISE STEP 3: EFFICIENCY FACTOR 304 X 0.83 = 253 ccy/hr

COMPACTION EXERCISE STEP 4: COMPACTORS REQUIRED Until tests are run in the field we do not know the exact conversion from lcy to ccy.

COMPACTION EXERCISE STEP 4: COMPACTORS REQUIRED 600 lcy/hr 253 ccy/hr compacted lift thickness 8 in. Assume a loose lift thickness was 10 in. the conversion factor would be 0.8, then 600 lcy  0.8 = 480 ccy

COMPACTION EXERCISE STEP 4: COMPACTORS REQUIRED 600 lcy/hr 253 ccy/hr compacted lift thickness 8 in. Assume a loose lift thickness was 11 in. the conversion factor would be 0.72, then 600 lcy  0.72 = 436 ccy

2 compactors are required. COMPACTION EXERCISE STEP 4: COMPACTORS REQUIRED 480 / 253 = 1.9 10 in. loose lift 436 / 253 = 1.7 11 in. loose lift Therefore at least 2 compactors are required.

EXERCISE No. 2 Trucks will deliver 450 lcy per hr of fill material (dry sand) for a road project. A self-propelled CAT CS-583C roller will be used to compact the fill.

EXERCISE No. 2 Using the maximum recommended compaction speed for this type roller it will require 5 passes to compact a 6 in. (compacted depth) lift. Assume a 50 min-hr efficiency.

EXERCISE No. 2 Width of CAT CS-583 roller = 7 feet STEP 1: COMPACTION REQUIREMENTS Width of CAT CS-583 roller = 7 feet What type of compactor is this? www.cat.com/cda/layout?m=37840&x=7

EXERCISE No. 2 Compacting Speed 2 - 4 mph Use 4 mph STEP 1: COMPACTION REQUIREMENTS CAT CS-583 roller is a smooth drum vibratory. Compacting Speed 2 - 4 mph Use 4 mph

EXERCISE No. 2 STEP 1: COMPACTION REQUIREMENTS Compacted lift thickness = 6 in. Number of passes required = 5

EXERCISE No. 2 STEP 2: PRODUCTION CALCULATION = 548 ccy

EXERCISE No. 2 STEP 3: EFFICIENCY FACTOR 548 X 0.83 = 456 ccy/hr

EXERCISE No. 2 STEP 4: COMPACTORS REQUIRED 450 lcy/hr 456 ccy/hr compacted lift thickness 6 in. Assume a loose lift thickness was 8 in. the conversion factor would be 0.75, then 450 lcy  0.75 = 338 ccy

COMPACTION EXERCISE Therefore only 1 compactor is required. STEP 4: COMPACTORS REQUIRED 338 / 456 = 0.74 8 in. loose lift Therefore only 1 compactor is required.

DYNAMIC COMPACTION Can achieve densification to a depths of about 30 ft using 30 ton weights and 100 ft drop heights.

DYNAMIC COMPACTION This is a 20 ton weight from 42 feet

DYNAMIC COMPACTION Usually only make contact with about 50% of the actual ground surface being compacted.

VIBRATORY PLATE COMPACTOR For granular soils and asphalt.

RAMMER Also known as a backfill tamper. Self-contained hand operated for use in confined spaces.

TRENCH ROLLER

WHEEL ATTACHMENT COMPACTORS

WHEEL ATTACHMENT COMPACTORS