procedure #105 concrete inspections

8/3/2019 Procedure #105 Concrete Inspections

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CONCRETE INSPECTION

NDE -105

_______________________________________________ Date_____12/16/2010________ Director, QA/QC, Turner Industries Group, L.L.C.

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TurnerIndustriesGroup, L.L.C.

Concrete InspectionDate: 12/16/2010

Procedure: NDE-105Rev. 0

1.0 CONCRETE INSPECTION

1.1 Scope

This section covers quality control and inspection documentation associated with construction of load bearing concrete structures. Examples of load bearing structures include: pump bases, equipmentfoundations, tank pads/rings, and paving subject to mobile equipment traffic. This section is notapplicable to non-loading bearing concrete such as paving limited to foot traffic only, ladder pads, etc.

1.2 Application

This section applies to Craft Supervisors, QC Supervisors, QC Inspectors, and Purchasing Personnel.

1.3 Reference Documents

American Concrete Institute (ACI), 318 (latest revision) Project Specifications Approved Drawings Turner Field QA Plan Turner Industries Group, L.L.C. QA/QC Manual

1.4 General

1.4.1 Concrete construction shall be according to Issued for Construction (IFC) Drawings, andProject Specifications.

1.4.2 Concrete suppliers, concrete testing service providers, and soil compaction testing service providers shall be Owner approved.

1.4.3 Prior to the purchase of concrete, the concrete design mix shall be submitted for review andapproval to the Project Engineer.

1.4.4 Sub-grade elevations shall be verified for compliance with the design drawings.

1.4.5 Upon delivery to the job-site the Inspector shall verify all construction materials meet Owner specifications.

1.5 QC Key Elements

1.5.1 As a minimum, the Craft Supervisor and the QC Supervisor or QC Inspector shall consider the following steps essential to quality control of concrete construction.

Construction materials, including concrete, are verified to meet Owner specifications. Proper site storage of construction materials, rebar and other embedmentshall be stored away from ground contact.

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Properly cleaned excavations, soil compaction, and backfill per IFCdrawings or specifications. Verification of the location, elevation, and dimensions of forms shall be verified prior to

making a pour. Tolerances shall meet the requirements of the Project Specifications unlessapproved construction drawings specify otherwise. Form work sturdy, tight, wetted/treated. Verification of reinforcing steel installation, anchor bolts, embedment, adhesives. Splicing of reinforcing steel shall meet the requirements of the approved drawings. Appropriate and approved ties shall adequately secure reinforcing steel. Reinforcing steel shall be free of dirt, grease, and other contaminants, prior to pour. Welding to reinforcement steel is not allowed unless approved by Owner Special/abnormal conditions are addressed (ie. hot/cold weather, pour logistics, etc.). Appropriate pre-placement assessment and planning. Proper placement and finishing equipment on hand. Appropriate manpower and experience/qualifications of craft personnel. Communication of the placement plan to all involved. Final inspection of placement preparations, appropriate acceptance signatures or documentation (pre-pour checklist). On site Owner approved concrete testing and documentation. Adherence to placement plan. Finishing to Owner specifications Curing to Owner specifications Form wrecking, visual inspection, blemish repair. Craft Supervisor/Inspector acceptance and documentation for post-pour activities. Owner acceptance/documentation.

1.6 Excavation

1.6.1 Excavations shall be cleared of plant life, root systems, and other debris.

1.6.2 The Craft Supervisor prior to excavation shall verify excavation location.

1.6.3 Drainage away from foundations shall be maintained both during and after construction.

1.6.4 Verification of sub grade soils and structural fill material shall be per IFC drawings.

1.7 Concrete Preparations

1.7.1 The QC Inspector will monitor field concrete placement preparations to ensure compliance toOwner Specifications.

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1.7.2 Formwork shall provide a smooth surface with tight joints. Treatment of forms with oils,wax, or other release agents shall be completed prior to installation of reinforcing bars andother embedment to avoid inadvertent contact with release agents.

1.7.3 All foreign material inside forms, such as wood chips, blocks, dried mortar, etc. shall beremoved prior to the installation of reinforcement steel and embedment

1.7.4 Form ties, spacers, etc shall not leave metal near exposed concrete surfaces. Rebar clearancesto exposed concrete surfaces shall be per IFC drawing dimensions and tolerances.

1.7.5 Any welding and/or heated bending of reinforcing steel shall have prior approval by theOwner.

1.7.6 Reinforcing steel shall be free of excessive corrosion; all embedments shall be generally cleanand free of any contaminants that might prevent concrete bonding

1.7.7 Reinforcement laps and bar splice lengths shall be determined by the specifications andapproved drawings.

1.7.8 All reinforcement steel and embeds shall be firmly held in place before and during concrete placement. In the event of movement beyond tolerances, the placement operation shall behalted and the displaced reinforcement or embeds shall be readjusted to original positions.

1.7.8.1 Reinforcement steel shall be tied at sufficient intervals to maintain bar location during

concrete placement and consolidation. Tie spacing also depends on handling andtraffic on the mat and the position it occupies.

1.7.9 As a final check of locations, dimensions and elevations, the Craft Supervisor may have asurveyor verify the following as applicable:

Plan location Location of anchor bolts. Embed components. Top of concrete.

Reinforcement elevations. Form block outs. Other critical dimensions and elevations. Verification may also be done by other qualified personnel.

1.8 Concrete Placement Planning

1.8.1 All concrete pours will involve some level of pre-pour planning. The Craft Supervisor shouldassess the specific job and determine the appropriate level of pre-pour planning.

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1.8.1.1 Large and/or complex pours should be well thought through and details addressedand captured in a written pour plan. As a minimum, the following items should beaddressed as applicable: Concrete delivery. Concrete testing (batch plant/on-site). Placing sequence/tuning. Equipment needed operability, quantity, and contingencies. Manpower/responsibilities. Conveying of concrete. Addition of High Range Water Reducing Agents (Super Plasticizer) or

other additives on-site or at the batch plant. Delay preparations/contingencies Weather conditions, hot (above 90F.) or cold (below 40F) weather

concreting techniques.

1.9 Concrete Preparations Acceptance

1.9.1 The Craft Supervisor shall initiate a pre-pour checklist as a final inspection of concrete preparations just prior to the pour. The Craft Supervisor will perform a visual inspection andcomplete and sign a Pre-Pour Checklist , Exhibit No. 8, as given in this section.

1.9.2 Once signed by the Craft Supervisor, the Pre-Pour Checklist is sent to the QC Inspector for

verification of accuracy and subsequent filing.

1.9.3 Once both the Craft Supervisor and QC Inspector have signed-off acceptance of the Pre-Pour Checklist, the Owners Inspector shall be contacted for final acceptance.

1.9.4 The QC Inspector shall ensure timely delivery of the concrete and check deliverytrucks time of departure, and cylinder rotation counter upon the trucks arrival on the site.

1.9.5 Weather conditions should be monitored prior to and during concrete pours, astemperature and moisture play important roles in the strength, workability, curing time, anddurability of concrete. The requirements of ACI 305 & ACI 306 shall be met, in addition to any

project specifications, which might apply.

1.9.6 The QC Inspector shall not allow the pour if it is raining or if the air temperature isexcessively cold, do not pour if the temperature is below 40F.

1.9.7 Surface finishes shall meet the requirements of approved drawings and the projectspecifications.

1.9.8 Freshly poured concrete shall be protected from detrimental weather conditions.

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1.9.9 Specific instances where concrete is cured in less than seven (7) days andsubjected to loading shall have prior approval of the Project Engineer.

1.10 Concrete Testing

1.10.1 Concrete requiring a compressive strength of 3,000 psi or more shall be tested in accordancewith ACI 318 except as follows:

1.10.1.1 One test shall be taken for each day's pour and at least one test be taken for each50 cubic yards placed. A test shall consist of four cylinders. One such cylinder shall be tested in the laboratory after seven days, one after 14 days and one after 28days with results submitted to the Owner as soon as-possible. Testing of theremaining cylinder shall be performed as required.

1.10.2 Air content, slump, and temperature tests shall be taken from the concrete samples for eachstrength test and whenever the consistency of the concrete appears to vary.

10.3 When the construction schedule requires a foundation to be loaded (equipment set) within a fewdays of the pour, additional strength test cylinders should be taken to allow for strength tests before the foundationis loaded (i.e. 2 day breaks).

10.4 An approved testing service shall be contracted and arrangements made for concrete testing. Normally testsamples are taken upon delivery to the job-site

1.10.4.1 When Super Plasticizer is used, concrete samples for slump tests shall be taken before adding Super Plasticizer to the mix. If Super Plasticizer is added at the batch plant, testing services should be provided at the batch plant.

1.10.4.2 When batch plant testing is performed, arrangements shall be made to communicatetest results to the job-site prior to concrete placement.

1.10.4.3 Samples for compressive strength tests and air content tests may be taken before or after the addition of Super Plasticizer to the mix.

1.10.5 The Craft Supervisor or QC Inspector shall communicate all necessary information needed by thetesting service, including the pour description, by fax, email, written memo, etc. The pour description shown on test reports shall be in sufficient detail to link concrete test reports tospecific concrete structures.

10.6 Slump tests shall be performed after any addition of water to the mix at the job-site. The deliveryticket shall state the max amount of water to be added.

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10.7 The QC Inspector or Craft Supervisor shall reject any concrete mix that is tested and determined to be outside of thespecification tolerances given on IFC drawings. The Owner's Inspector shall be notified of any rejection of concrete.

Concrete Placement and Consolidation

1.11.1 Standing water in excavations shall be removed before concrete placement.

1.11.2 Concrete poured against earth shall have the soil pre-wetted or sealed with a vapor barrier to prevent excessive loss of moisture from the fresh concrete.

1.11.3 Concrete shall be deposited near its final location. Concrete shall not be allowed toflow laterally unless the whole mix is moving without segregation.

1.11.4 Concrete should be placed directly in corners and ends of walls first; flow should betoward the center of formwork.

1.11.5 Drop chutes shall be used where concrete free fall is over six feet or to avoid strikingreinforcement steel.

1.11.6 Consolidation shall be done using properly sized vibrators in accordance with ACI309.

1.11.7 Vibrators shall be applied systematically at close intervals so that vibrated areas of concrete overlap without omission. Vibration shall continue until concrete is thoroughlyconsolidated and voids are filled as evidenced by the leveled appearance of concrete at theexposed surface, and the embedment of surface aggregate.

1.12 Finishing and Curing

1.12.1 When given, concrete finishing shall be as specified on IFC drawings/projectspecifications.

1.12.1.1 Concrete finishing shall not take place while there is excessive wetness or bleedwater at the surface of the concrete.

1.12.1.2 Curing compounds shall be approved by the Client prior to their use.

1.12.2 When given, concrete curing shall be according to IFC drawings/project specifications. If no curing method is given one of the following methods should be used:

Wet coverings (burlap, sand) Plastic Coverings Ponded water Sprinkling or soaking Membrane-forming curing compounds

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Note: Reference ACI 308 Chapter 2 for explanation of techniques.

1.12.3 After form removal and any blemish repair, the Craft Supervisor shall initiate a post-pour

checklist as a final inspection of the completed concrete structure. The Craft Supervisor will perform a final visual inspection and complete Exhibit No. 30, Concrete Systems AcceptanceForm.

1.12.4 Once signed by the Craft Supervisor the Concrete Systems Acceptance Form is sent to the QCInspector for acceptance and signature.

1.12.5 Once both the Craft Supervisor and the Layout Supervisor/Surveyor have signed-off acceptanceof Exhibit No. 30, Concrete Systems Acceptance Form, the Owner's Inspector shall becontacted for a final Owner's acceptance.

1.13 Inspection Documentations and Owner Acceptance

1.13.1 The QC Inspector is responsible for retention and compilation of all inspection documentationassociated with placement of load bearing concrete.

1.13.2 Concrete Placement Acceptance Packages shall consist of the following:

Sign-off of Exhibit No. 8, Pre-Pour Inspection Record Sign-off of Exhibit No. 30, Concrete Systems Acceptance Original inspection/testing reports * (Concrete Test Reports).

*In some cases 28 day compressive strength test results may not be available. In this case the Post-Pour Checklist should indicate the final test results are not currently available. The Owner'sInspector can accept the final documentation packages. The QC Inspector will forward the final testreports to the Owners Inspector upon receipt.

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