Significant factors in the generation of waste in this Section include temporary bracing, formwork, and hazardous fluids.
See "Cement and Concrete: Environmental Considerations" Environmental Building News, Vol. 2, No. 2 for a thorough discussion of environmental issues . Concrete is energy intensive material, even as a recycled product.
Consider alternative foundation systems. Pier foundations use far less concrete than poured full-height foundation walls or slab-on-grade foundations (be sure to provide adequate insulation and air sealing details at the floor system). Building a shallow footing and frost walls with horizontal insulation, which effectively reduces the frost depth, can cut concrete use considerably in northern climates.
Consider insulated wall forms systems. These use less concrete than conventional poured foundation walls.
Specify minimal admixture use. If clients have chemical sensitivities, specify minimal use of chemical additives for controlling concrete properties and workability--at least until adequate studies are done to determine whether offgassing might be a realistic concern. Sucrose-based retarders should not pose any problems.
Specify fly ash. Fly ash can be added to most concrete mixtures, usually with an improvement in workability and strength. Proportions up to 15% can be achieved easily, and higher levels are possible.
Large buildings are demolished with explosives; smaller structures with hand or machine-held mechanical chisels. Partial demolition is usually done by sawing and drilling. Demolished concrete can be recycled by crushing it into aggregate-sized pieces (taking energy). This is not used for new concrete, but as fill or aggregate in asphalt paving. Whenever possible, specify crushed concrete debris as clean fill around buildings or as aggregate under parking lots and driveways. Coordinate with Div. 2.
Consider pre-cast units when possible. There is less waste and no admixtures.

SECTION 03300 — CAST-IN-PLACE CONCRETE


PART 1 — GENERAL

1.01 DESCRIPTION

Extent of concrete work is shown on Drawings, and includes formwork, reinforcement, accessories, cast-in-place concrete, finishing and curing.

1.02 REFERENCE STANDARDS

Except as modified by the requirements of these Contract Documents comply with ACI 301 "Specifications for Structural Concrete Buildings" ACI 318 "Building Code Requirements for Reinforced Concrete":
Use or delete one or both of the following…see also Cold Weather Concrete checklist.
ACI 306.1 "Standard Specification for Cold Weather Concreting".
ACI 305 " Standard Specification for Hot Weather Concreting".
If Architectural Grade surfaces are in project, use or delete the following…
ACI 303 "Guide to Cast-in-Place Architectural Concrete Practice" Cresset Concrete Standards (CCS): Published by Cresset Chemical Company; One Cresset Center, Box 367, Weston, OH 43569; fax 419-669-2200; phone 800-367-2020.

1.03 CERTIFICATES

Submit to Architect certificates, signed by concrete producer and Contractor, of materials and mix proportions used.

1.04 SUBMITTALS

Use, or delete the following…
Submit manufacturer's product data with installation instructions for proprietary materials including reinforcement and forming accessories, admixtures, joint materials, hardeners, form release agents, curing materials, cleaners and others as requested by Architect.

Submit five (5) copies of reinforcement shop drawings indicating sizes, spacings, locations, and quantities, bending and cutting schedules, supporting and spacing devices.

Submit written report to Architect for each proposed concrete mix at least 15 days prior to start of work. Do not begin concrete production until mixes have been reviewed and are acceptable to Architect.

Submit slump test reports for slump and compression strength.

If Architectural Grade surfaces are involved, include the following; otherwise omit…
1.05 QUALITY ASSURANCE

Comply with ACI 301 and ACI 303 except where otherwise indicated.

Installer shall have [5] [________] years experience installing concrete with Architectural Grade surfaces equivalent to those required on this Project.

Conduct a preinstallation conference to review scheduling and methods employed to assure quality of Architectural Grade concrete. Discuss coordination of release agent application, formwork and steel erection, inspection, placing of concrete, protection of forms and protection of hardened concrete to avoid contamination of release agent and damaging hardened concrete.

Construct [wall] [panel] not less that [4 x 4 feet ] [___________] at location selected by [Architect][____________]. Use materials and workmanship proposed for Architectural Grade surfaces. Accepted mockup establishes a range of acceptable visual performance for Architectural Grade concrete. At conclusion of Work, mockup [shall be removed from Site.] [may remain as part of Work.]


PART 2 — PRODUCTS

2.01 MIX PROPORTIONS AND DESIGN

Proportion mixes complying with mix design procedures specified in ACI 301.

Mix designs may be adjusted when material characteristics, job conditions, weather, test results or other circumstances warrant. Do not use revised concrete mixes until submitted to and accepted by Architect.

Use air-entraining admixture in all concrete, providing not less than 5.5% nor more than 7.5% entrained air for exposed concrete, and from 2.5% to 4.5% for other concrete.

Mix concrete according to the following:

	Footings & Foundations	Ext.Slabs, Walks &Steps
water-cement ratio	6 gal/sack	6 gal/sack
maximum aggregate size	1 1/2"	1"
slump	6" ± 1"	5" ± 1"
minimum 28 day compressive strength	3000 psi	3500 psi

2.02 CONCRETE MATERIALS

Use locally mined and produced materials whenever possible. Do not use toxic additives.

Portland Cement: ASTM C 150
Aggregates: ASTM C 33, except local aggregates of proven durability may be used when acceptable to Architect.
Water: Clean, drinkable.
Fly Ash: ASTM C 618. Limit to 15% of cement content by weight.
Air-Entraining Admixture: ASTM C 260.
Water-Reducing Admixture: ASTM C 494, type as required to suit project conditions. Only use admixtures which have been tested and accepted in mix designs, unless otherwise acceptable.

2.03 REINFORCING MATERIALS

Deformed Reinforcing Bars: ASTM A 615, Grade 60.
Welded Wire Fabric (WWF): ASTM A 185.

2.04 FORM MATERIALS

Provide form materials with sufficient stability to withstand pressure of placed concrete without bow or deflection. For exposed concrete surfaces, provide form materials suitable to project conditions.

2.05 RELEASE AGENT

The following meet any regulations, but still have some VOCs which can cause irritatiion.
Use biodegradable, non-toxic, non-flammable, non-carcinogenic, low- or no-odor, and low-VOC (less than 200 g/l) material.

Acceptable Manufacturers:
• Cresset Chemical Company; One Cresset Center, Box 367, Weston, OH 43569; fax 419-669-2200; phone 800-367-2020.
• W.R. Meadows, Inc. P.O.Box 543, Elgin, IL 60121; 708-683-4500; fax 708-683-4544.

The following product is made from flaxseed and is totally free of VOCs. It is more expensive.
Use Bio-Form® by Leahy-Wolf Company, 1951 N. 25th Ave., Franklin Park, IL 60131, (888) 873-5327.

For Architectural Grade surfaces, see Cresset Concrete Specs for additional material…

2.06 RELATED MATERIALS

Underslab Moisture Barrier: Clear polyethylene sheet at least 10 mils thick.

It is difficult to get contractors to use anything but 6 mil material. Because of its resistance to puncturing, cross-laminated sheeting is better for under concrete or on foundation wall, below grade for improved damproofing:
tu-tuf^®4 cross-laminated polyethylene sheeting by Sto-Cote Products, Inc. (P.O. Drawer 310, Richmond, IL 60071, 800-435-2621), rated 0.04 perms or less.
or
Moistop sheeting by Fortifiber Corp. (19342 Lake Montcalm R.d, Howard City, Michigan (800) 442-2587).

Coordinate use of curing compounds and sealers with flooring requirements.
Membrane-Forming Curing Compound: Use water-based, biodegradable, solvent-free, non-toxic, non-flammable, non-carcinogenic, low- or no-odor, and low-VOC (less than 250 g/l) material, complying with ASTM C 309, Type I.

Sealer and Hardener: Use water-based, non-VOC solution specifically designed for protecting concrete floors against abrasion, dusting and spillage.

Joint Fillers: As required to suit project conditions. Homex® 300 Expansion Joint Filler by Homasote Co., P.O.Box 7240, West Trenton, NJ 08628-0240, (800) 257-9491.

Waterstops: Purpose made polyvinyl chloride, 4" wide, maximum possible lengths.

Floor Cleaner: Use water-based, biodegradable, non-toxic, non-flammable, non-carcinogenic, low- or no-odor, and low-VOC (less than 50 g/l) material, free from chlorinated or fluorinated solvents.


PART 3 — EXECUTION

For Architectural Grade surfaces, see Cresset Concrete Specs for guidelines and additional material…

3.01 FORMING AND PLACING CONCRETE

For job site mixing, use drum type batch machine mixer,mixing not less the 1-1/2 minutes for one cu. yd. or smaller capacity. Increase mixing time at least 15 seconds for each additional cu. yd. or fraction thereof.

For ready-mix concrete, comply with ASTM C 94.

Before concrete pours, designate locations or uses for excess concrete. Options include:
Edit the following to suit project
additional paving, post footing anchorage, swale rip-rap reinforcing, mud slab, flowable fill, footing bottom, retaining wall footing ballast, storm structure covers, underground utility pipe kickers, storm pipe flared end section, toe wash protection, and shoulder and toe outfall restraints for temporary erosion pipes.

Formwork: Construct formwork so that concrete members and structures are of correct size, shape, alignment, elevation and position. Provide openings in formwork to accommodate work of other trades. Accurately place and securely support items built into forms. Clean and adjust forms prior to concrete placement. Apply form release agents or wet forms, as required to eliminate mortar leaks.

Reinforcement: Position, support and secure reinforcement against displacement. Locate and support with metal chairs, runners, bolsters, spacers and hangers as required. Set wire ties so ends are directed into concrete, not toward exposed surfaces. Install welded wire fabric in as long lengths as practicable, lapping at least one mesh.

Joints: Provide construction, isolation and control joints as indicated or required. Locate construction joints so as not to impair strength and appearance of structure. Place isolation and control joints in slabs-on-ground as indicated or as required to stabilize differential settlement and random cracking.

Embedded Items: Set and build into work anchorage devices and other embedded items required for other work that is attached to, or supported by case-in-place concrete. Use setting diagrams, templates and instructions provided by others for locating and setting.

Concrete Placement: Comply with ACI, placing concrete in a continuous operation within planned joints or sections. Do not begin placement until work of other trades affecting concrete is completed. Consolidate placed concrete using mechanical vibrating equipment with hand rodding and tamping, so that concrete is worked around reinforcement and other embedded items and into forms.

Check concrete within 24 hours of placement for flatness, levelness, and other specified tolerances. Adjust formwork and placement techniques on subsequent pours to achieve specified tolerances.

3.02 PROTECTIONS

Protect concrete from physical damage, reduced strength or weathering resistance due to weather extremes during mixing, placement and curing.

3.03 CONCRETE FINISHES

Consider including a Schedule of Finishes if the scope or location of different kinds of concrete surfaces is not shown on the Drawings or adequately handled with the text below.
Scratch Finish: Apply scratch finish to monolithic slab surfaces that are to receive concrete floor topping. After placement plane surfaces level. Slope surfaces uniformly to drains where required. After leveling roughen surface before final set with stiff brushes or brooms.

Rubbed Finish: At exposed vertical surfaces remove fins and projections, moisten and rub smooth immediately on stripping forms until a uniform color and texture is produced.

Slab Trowel Finish: Apply trowel finish to monolithic slab surfaces that are exposed to view and that are to be covered with material applied directly to concrete. Remove fins and projections, patch defective areas with cement grout, and rub smooth. Consolidate concrete surfaces by finish troweling, free of trowel marks, uniform in texture and appearance. Maintain surface flatness width maximum variation of 1/8" in 10'. In areas with floor drains, maintain floor level at walls and pitch surfaces uniformly to drains.

Non-slip Broom Finish: Apply non-slip broom finish to exterior concrete platforms, steps, walks and ramps, and elsewhere as indicated. Immediately after trowel finishing slightly roughen surface by brooming with fiber bristle broom perpendicular to main traffic route.

Textured Finish: Impress and removed expanded metal industrial mesh while the concrete is in a plastic state to give diamond-shaped texture complying with ILHR 69.37(1).

3.04 CURING

Begin initial curing as soon as free water has disappeared from exposed surfaces. Where possible, keep continuously moist for not less than 72 hours. Continue curing by use of moisture-retaining cover or membrane-forming curing compound. Do not use curing compounds on concrete slabs which are to be covered with tile using a cementitious bond coat.

Cure formed surfaces by moist curing until forms are removed. Provide protections as required to prevent damage to exposed concrete surfaces.

3.05 SEALING

If moisture-retaining cover is used for curing, use Cresset ‘Super-Trete’™ 110-VOC for sealing exposed concrete floors once the concrete is cured. If membrane-forming curing compound is used for curing in these areas, apply an additional application of Cresset ‘Super-Trete’™ 110-VOC for sealing once the concrete is cured.


END OF SECTION 03310

CAST-IN-PLACE CONCRETE 03300-#
courtesy of Design Coalition, Architects. , Madison, Wisconsin, USA ~~ www.designcoalition.org