00440.13 371 Section 00440 - Commerc ial Grade Concrete Description
00440.00 Scope - This Work consists of furnishing, placing and finishing Commercial Grade
Concrete (CGC). Materials
00440.10 Materials - Provide sampling, testing, and quality control according to Section 00165.
Furnish Material s meeting the following requirements: Admixtures ................................................................................................. 02040 Bonding Agents .......................................................................................... 02070 Cement ....................................................................................................... 02010 Curing Materials ......................................................................................... 02050 Grout .......................................................................................................... 02080 Supplementary Cementitious Materials ...................................................... 02030 Water .......................................................................................................... 02020
00440.11 Proportions - Furnish, in writing to the Engineer, the proportions by weight of the following
Material s before using any CGC: • air entraining admixtures • cement • each size of Aggregate • fly ash • other admixtures • water
00440.12 Properties of Commercial Grade Concrete - Furnish a workable CGC mixture that is
uniform in composition and consistency, and unless otherwise shown or specified, has the following characteristics: • Entrained Air - 4.0 to 7.0 percent Slump - 5 inches or less For concrete sidewalks, ramps, driveways, or other hand finished surface applications, and when using a high range water reducing admixture, provide a slump of 8 inches or less as approved by the Engineer. Compressive Strengt h - ASTV m inimum of 3,000 psi at 28 Days Temperature - Minimum 50 ° F to maximum 90 °F
00440.13 Field- Mixed Concrete - CGC Work items listed in 00440.14(a) may be field-mixed
conventionally, or by volumetric/mobile mixers conforming to ASTM C685. When a pproved, concrete sidewalks, concrete curb ramps, concrete driveways, and other flat concrete surfaces may be field-mixed using volumetric/mobile mixers conforming to ASTM C685,r equest approval prior to placement. For all other CGC applications, submit written request to the Engineer for approval to use volumetric/mobile mixers conforming to ASTM C685 at least 21 Days prior to placement. Pre-packaged dry blended concrete from the QPL may be used for Work items listed in 00440.14(a). 00440.14 372 00440.14 Acceptance Sampling and Testing :
a.General - Acceptance sampling and testing will be based on tests performed by the Contractor’s QCT from samples obtained at the site of placement from the discharge of the delivery vehicle. CGC mixture may be accepted visually for the following items of Work : Work Item Section Bollards ................................................................................... 00815 Electrical Conduit Backfill ........................................................ 00960 Fence Post Footings ............................................................... 01050 Hydrant Thrust Blocks ............................................................. 01160 Irrigation System Thrust Blocks ............................................... 01120 Mailbox Support Footings ........................................................ 01070 Outlet Protection Blocks .......................................................... 00430 Perforated Steel Square Tube Sign Support Footings ............ 00920
b.Delivery Tickets - Send a delivery ticket with each load of CGC recording the source, Day , time of batch, size of load, and quantity of individual constituents in the load. Delivery tickets are not required for field-mixed concrete except when volumetric/mobile mixers ar e used. Labor
00440.30 Quality Control Personnel - Provide technicians having CSTT and QCT technical
certifications. Construction
00440.40 General :
a.Mixing - Mix CGC to the extent that ensures a uniform distribution of Material s throughout the mixture.
b.Placing - Place CGC according to the appropriate Sections in which CGC is required and the following: • Place using the best common practices to avoid se gregation. • Vibrate and spade to achieve a dense homogeneous concrete, free of voids and Rock pockets. Place within 90 minutes after batching and mixing. When haul time or placement conditions warrant exceeding the time of discharge, submit a detailed breakdown of the estimated time needed from batching to discharge of a load along with the measures that are taken to ensure slump, temperature and uniformity are maintained. Submit in advance to establish a new time limit at the Engineer’s discretion.
c.Forms - Provide forms for CGC according to the appropriate Sections in which CGC is required and best common practices. Place to the lines and grades shown or directed.
d.Weather - Do not place CGC when the air temperature is below 35 °F without approval. Protect CGC from freezing if the air temperature is expected to drop below 35 °F during the first 5 Calendar Day s after placement. 00440.90
e.Curing - Cure CGC by covering with wet burlap, canvas, Sand, or other acceptable Material , and keep moist for a minimum of 7 Calendar Day s. Curing compounds may be used except on concrete surfaces or reinforcement that will come in contact with adjacent concrete pours. Use curing compounds according to the following: Section Item Type 1 or 1 -D (Clear) Type 2 (White -Pigmented) 00480 Drainage Curbs * * 00599 Slope Paving Curbs and Berm Paving Yes No 00759 Walks, Curb Ramps, Driveways, Surfacing s, Curbs, and Islands * * * Use Type 2 except when the Engineer requires Type 1 or 1- D Apply curing compounds at a rate of not be less than 1 gallon per 150 square feet.
00440.41 General Surface Finish - Give concrete surfaces a general surface finish, according
to 00540.53(a), in addition to the finish specified for a particular item of Work .
00440.42 Replacement or Price Reduction - Remove concrete represented by cylinders that fail to
meet the minimum strength requirement and replace at no additional cost to the Agency. If the Engineer determines that the low -strength concrete is suitable for the purpose intended, the Contractor may accept a price reduction established by the Engineer instead of removal and replacement. Measurement
00440.80 Measurement - No measurement of quantities will be made for CGC.
Payment
00440.90 Payment - No separate or additional payment will be made for CGC. Paymen t will be
included in payment made for the appropriate items under which this Work is required.
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Source: Oregon Standard Specifications for Construction, 2024 Edition. Pages 437–439 of 1,268. View official source ↗