NDRM & CPA Spring Concrete Workshop Bismarck, ND CPA Spring Concrete Worksh… · NDRM & CPA Spring Concrete Workshop Bismarck, ND ... 3 Day 7 Day 28 day 56 Day 3 Day 7 Day 56 day

NDRM & CPA Spring Concrete Workshop

Bismarck, ND

Controlled Low Strength Materials

March 13, 2012 Presented by

Hank Hauge

Technical Services

Strata Corporation

Terms Used for

Controlled Low Strength Material

(CLSM)

• Flowable fill

• CLSM (regular or lightweight)

•Grout Backfill

•Controlled density fill (CDF)

• Trench fill

• Flowable mortar

• Flowable grout

Controlled Low-Strength Materials

(CLSM)

• Material that results in a compressive strength

of 1,200 psi (8.3 MPa) or less

• A self-compacting cementitious material

• Self-leveling (minimal placing effort required)

• No vibration or tamping needed

• Excavatable ( < 300 lb/in2 Compressive Strength)


(CLSM)

Flowable fill Applications

Backfill Structural Fill

Sewer Trenches Replace low quality

Conduit Trenches soils

Utility Trenches Mud Jacking

Building Excavations Sub-footings

Bridge Abutments Floor Slab Overlay

Pipe Bedding Road base


(CLSM)

Flowable fill Applications

Other Applications

Closing underground storage tanks

Slope stabilization

Mud mats

Abandoned sewers/mine shafts

Highway barriers

Airport runway blast pads

Air Modified


(CLSM)

Flowable fill

• Regular - CLSM

• Density (Unit Wt.) > 50 lb/ft3 (800 kg/m3)

• Up to 35% air

•28 Day Compressive Strength <1200 lb/ft2

Air Modified


(CLSM)

Lightweight fill

• Low-Density CLSM

• Density (Unit Wt.) < 50 lb/ft3 (800 kg/m3)

• Up to 80% air

Terms Used for

Air Modified CLSM

• CDF

• Low-Density CLSM

• Lightweight cellular concrete

• Foamed concrete


(CLSM)

Air Modified

Other Applications

Soil Erosion Control

Firewalls

Precast Architectural Panels

Roof Insulation

Wall Insulation

Advantages of using

Air Modified Flowable Fill and

Lightweight Fill

• Requires no compaction equipment/minimal labor

• Flows readily in and around pipes, corners, etc.

•Can be cut or trenched without cave-ins

• Reduced shrinkage

• Flexible Design Parameters

Typical Questions That

Specifiers Consider…..

•Is the void completely filled?

•Will there be shrinkage & settlement?

•Is the material homogeneous throughout?

•Can it be excavated at a later date?

Typical Testing Procedures for CLSM

• ASTM Test Method for Flow Consistency of CLSM

(D 6103)

• ASTM Test Method for Preparation and Testing of CLSM

Test Cylinders (D 4832)

• ASTM Test Method for Unit Weight, Yield, and Air

Content (Gravimetric) of CLSM (D 6023)

• ASTM Practice for Sampling Freshly Mixed CLSM

(D 5791)

• ASTM Test Method for Ball Drop on CLSM to Determine

Suitability for Load Application (D 6024)

CLSM

is a

Super Soil!

Especially Air Modified

Useful Test Methods

• CBR ( ASTM D 1883)

• Triaxial Shear-Consolidated Drained

(USACE EM 1110-2-1906)

• One-Dimensional Consolidation of Soils

(ASTM D 2435)

• Permeability (ASTM D 5084)

• Freeze-Thaw for Soil-Cement Mixtures (ASTM D 560)

• Bleeding (ASTM C 940)

• Mortar Penetrometer for in place CLSM

Sample Test Results as Reported in

The Design and Application of Controlled Low Strength Materials

Howard and Hitch,Editors

ASTM STP 1331

Air-Modified CLSM Compressive Strength, Direct Shear-Strength, California Bearing Ratio (CBR)

Cement Fly Ash Water Sand

(lbs/cy) (lbs/cy) (lbs/cy) (lbs/cy) 3 Day 7 Day 28 day 56 Day 3 Day 7 Day 56 day 3 Day 7 Day 56 day

Trial Mix 1 35.2% Air

100 0 250 2380 18 21 33 53 0.07 0.34 0.84 22.9 28.9 52.3

angle 27.9 angle 26.6 angle 22.5


200 0 250 2295 68 110 131 121 1.04 1.78 2.92 56.1 71.5 123.0



100 200 250 2168 57 74 119 138 0.58 0.74 2.94 39.6 49.6 123


California Bearing Ratio (%)Compressive Strength (psi) Direct Shear Strength (tons/sf)

As Reported in

The Design and Application of Controlled Low Strength Materials

Howard and Hitch,Editors

ASTM STP 1331

AASHTO Soils Classification vs. CBR Index

(Typical Compacted Fill)

Soil Description CBR Index (%)

56 day air-modified CLSM 50-130

Base rock, well graded 60-80

Gravel, poorly graded 35-60

Gravel, uniformly graded 25-50

Silty gravel 40-80

Clayey gravel 20-40

Silty, sandy silts, gravely silts 5-15

Lean Clays, sandy clays, gravely clays 5-15

Organic silts, lean organic clays 4-8

Fat clays, organic clays 3-5

Typical Engineering Properties of a

Air Modified CLSM Mix

• 50- 300 lb/in2 Unconfined 28 day

Compressive Strength

• CBR-7 Day, 25-40 % (56 Day, 50-130%)

• 0.30-0.90 tons/ft2 Direct Shear Strength

• 28 Day Friction Angle 25-40 Degrees

• 0% Bleed (2-3% for Reg. CLSM)

Typical Flowable Fill Mixture

Ingredients

• Portland Cement

• Fly Ash (or other by-products)

• Water

• Fine or Coarse Aggregate (or both)

•Chemical Admixtures (e.g. high dosages of air-entraining admixtures)

Typical Lightweight Fill Mixture

Ingredients

• Portland Cement

• Fly Ash (or other by-products)

• Water

• Prefoamed Foam

Lightweight Fill - CLSM

Preformed foam is typically produced on-site by:

• Diluting the foam concentrate with water prior to combining it with compressed air

• Passing the mixture through a foam generator

“Compressed Air Preformed Foam System”

Foaming Agent

Preformed foam can be produced either

at the batch plant or job-site by using

pressurized water from the water mains

or the ready-mix truck water tank

“Pressurized Water Preformed Foam System”

CLSM Foaming Agent

Flowable Fill Lightweight Fill

(Regular CLSM) (Low-Density CLSM)

Densities > 50 lb/ft3 Densities < 50 lb/ft3

15% to 35% air content Up to 80% air content

Benefits of CLSM

Foaming Agent

• Optimum workability - fluid or plastic consistency

• Stable density (unit weight)

• Easily placed by chute or pumps

• Good thermal insulation

• Reduced bleeding, settlement, and shrinkage

• Can produce flowable fill and lightweight fill

mixtures

Let’s Look at Some Examples

Lightweight Fill Application

Slab Overlay

56,000 ft2

5,200 yd3

Requirements:

Wet Density: 28 to 35 lb/ft3

Minimum Compressive

Strength : 80 psi @ 28 days

Lightweight Fill Application

Industrial Roof Overlay, Bismarck ND

Benefits of Air Modified

CLSM

• Reduced water content

• Increased yield

• Optimum workability - fluid or plastic

consistencies

• Little or no bleeding

• Reduced settlement and shrinkage

• No segregation

• Cost effective compared to in-place cost of

compacted soil

Any Questions?

Thank You for Your Time

Documents

NDRM & CPA Spring Concrete Workshop Bismarck, ND CPA Spring Concrete Worksh… · NDRM & CPA Spring Concrete Workshop Bismarck, ND ... 3 Day 7 Day 28 day 56 Day 3 Day 7 Day 56 day