SECTION 02242

SOIL CEMENT STABILIZATION

PART 1 GENERAL

SECTION INCLUDES

Excavation, treatment and placement of subsoil mix.

RELATED SECTIONS

Section [01400 - Quality Control] [01410 - Testing Laboratory Services]: Testing fill compaction.

Section 02218 - Landscape Grading: Filling of topsoil [and] [_________] to finish grade elevation.

Section 02222 - Excavation: General site and building excavation.

Section 02223 - Backfilling: General site and building backfilling.

Section 02225 - Trenching: Backfilling of utility trenches.

Section [03300 - Cast-in-Place Concrete] [03001 - Concrete]: Concrete materials.

REFERENCES

ASTM C150 - Portland Cement.

ASTM D1633 - Test Method for Compressive Strength of Molded Soil Cement Cylinders.

SUBMITTALS

Submit under provisions of Section [01300.] [_____.]

Submit mix design and materials mix ratio that will achieve specified requirements.

[Samples: Submit [10] [___] lb ([4.5 [___] kg) sample of each type of fill, in air-tight containers, to testing laboratory.]

ENVIRONMENTAL REQUIREMENTS

Do not install mixed materials in wind in excess of [10] [___] mph ([16] [___] Kph) or when temperature is below [40] [___] degrees F ([5] [___] degrees C).

PART 2 PRODUCTS

FILL MATERIALS

Aggregate: [Crushed] [Gravel], [pit run] [angular] [__________], natural stone, free of friable material or debris, graded within the following limits:

Sieve Size	Percent Passing

1 inch (25 mm)	[100] [___]

3/4 inch (19 mm)	[80] [___] to [95] [___]

5/8 inch (16 mm)	[60] [___] to [80] [___]

3/8 inch (9 mm)	[5] [___] to [60] [___]

[Sand] [__________]: Natural river or bank sand, free of debris.

Subsoil: [Reused] [Imported]; pulverize [during the mixing process] to pass a [1] [___] inch ([25] [___] mm) screen size, free of rock or debris.

Cement: ASTM C150 Portland cement, [Normal Type I.] [Sulphate Resistant Type V.]

Curing Seal: [Asphalt emulsion primer.] [_______________.]

Geotextile Fabric: [_______________.]

EQUIPMENT

Equipment: Capable of excavating subsoil, mixing and placing materials, wetting, consolidating, and compacting of material.

SUBSOIL MIX

Mix subsoil, cement, [sand] and aggregate in accordance with [__________.] [Quantity of cement not to exceed [10] [___] percent of dry mixed materials by volume.]

Carefully add water to the mix to achieve a consistent mixture without lumping. Do not create a wet plastic consistency.

[Mix to obtain a minimum compressive strength of [450] [___] psi ([3] [___] MPa) at [7] [___] days.]

Obtain [Architect/Engineer] [Owner] approval of the mix before proceeding with placement.

PART 3 EXECUTION

EXAMINATION

Verify fill materials to be reused, are acceptable.

Do not backfill over frozen or spongy subgrade surfaces.

PREPARATION

[Coordinate requirements with piling operations.]

EXCAVATION

Protect adjacent structures which may be damaged by this work.

Excavate subsoil to a depth sufficient to accommodate soil stabilization, construction operations, and[.] [_______________.]

[Proof roll subgrade to identify soft areas and excavate those areas.]

[Excavation not to interfere with normal [45] [___] degree bearing splay of any foundation.]

Remove lumped subsoil, boulders, or rock up to [1/3] [___] cu yd ([0.25] [___] cu m) measured by volume. Larger material will be removed under Section [02202.] [_____.]

Notify Architect/Engineer of unexpected subsurface conditions. Discontinue affected Work in area until notified to resume work.

Correct unauthorized excavation at no extra cost to Owner.

Correct areas over-excavated by error [in accordance with Section 02222.] [__________.]

[Stockpile excavated material in area designated on site [and remove excess material not being reused, from site].] [Remove excavated material from site.]

SOIL TREATMENT AND BACKFILLING

Place geotextile fabric over subsoil surface, lap edges and ends.

Site mix subsoil, backfill[.] [and compact.] Wet the treated subsoil mix to achieve mix formulation.

[Place mix material in continuous layers not exceeding [12] [___] inches ([300] [___] mm) depth.

Maintain optimum moisture content of mix materials to attain required stabilization and compaction capability.

Do not exceed [30] [___] minutes in placing adjacent mixed material.

Commence compaction of mix no later than [60] [___] minutes after placement.

[Slope grade away from building minimum [2] [___] inches in 10 ft ([150] [___] mm in 3 m), unless noted otherwise.]

Make grade changes gradual. Blend slope into level areas.

At end of day, terminate completed Work by forming a straight and vertical construction joint.

[Remove surplus mix materials from site.]

CURING

Immediately following compaction of mix, seal top surface with curing seal.

TOLERANCES

Top Surface of Fill: Plus or minus [one] [___] inch ([25] [___] mm) from required elevations.

FIELD QUALITY CONTROL

Field [inspection and] testing will be performed under provisions of Section [01400.] [01410.] [_____.]

Compression test and analysis of hardened fill material will be performed in accordance with [ASTM D1633.] [__________.]

If tests indicate Work does not meet specified requirements, remove Work, replace and retest at no cost to Owner.

Frequency of Tests: [____________________.]

SCHEDULE

Fill Under Slabs-On-Grade:

Fill to [___] inches ([_____] mm) thick.

Fill Under [Asphalt] [Concrete] [__________] Paving:

Fill to [___] inches ([___] mm) below finish paving elevation.

Fill to Correct Over Excavation:

Subsoil Mix: Flush to required elevation.

END OF SECTION