Section 03350 CONCRETE TESTING

Section 03350

_{CONCRETE TESTING}

PART 1 - GENERAL

1.1 SUMMARY

A. Section Includes:

1. CONTRACTOR requirements for testing of concrete and grout.

2. Acceptance criteria for concrete.

B. Related Specification sections include but are not necessarily limited to:

1. Division 01, Additional General Requirements

2. Section 03123, Controlled Density Concrete

3. Section 03200, Reinforcement Steel

4. Section 03300, Cast In-Place Concrete

1.2 RESPONSIBILITY AND PAYMENT

A. CONTRACTOR will hire an independent Testing Agency/Service Provider to perform the following testing and inspection and provide test results to the ENGINEER..

1. Testing and inspection of concrete and grout produced for incorporation into the Work during the construction of the Project for compliance with the Contract Documents.

2. Additional testing or retesting of materials occasioned by their failure, by test or inspection, to meet requirements of the Contract Documents.

3. Strength testing on concrete required by the ENGINEER when the water-cement ratio exceeds the water-cement ratio of the typical test cylinders.

4. In-place testing of concrete as may be required by ENGINEER when strength of structure is considered potentially deficient.

5. Additional testing and inspection required because of changes in materials or proportions requested by CONTRACTOR.

6. Testing of materials and mixes proposed by the CONTRACTOR for compliance with the Contract Documents and retesting in the event of changes.

7. Other testing services needed or required by CONTRACTOR such as field curing of test specimens and testing of additional specimens for determining when forms, form shoring or reshoring may be removed.

8. CONTRACTOR will pay for services defined in Paragraph 1.2A.1 through 7.

B. Duties and Authorities of Testing Agency/Service Provider:

1. Any Testing Agency/Service Provider or agencies and their representatives retained by CONTRACTOR for any reason are not authorized to revoke, alter, relax, enlarge, or release any requirement of Contract Documents, nor to reject, approve or accept any portion of the Work.

2. Testing Agency/Service Provider shall inform the CONTRACTOR and ENGINEER regarding acceptability of or deficiencies in the Work including materials furnished and work performed by CONTRACTOR that fails to fulfill requirements of the Contract Documents.

3. Testing Agency to submit test reports and inspection reports to ENGINEER and

CONTRACTOR immediately after they are performed.

a. All test reports to include exact location in the Work at which batch represented by a test was deposited.

b. Reports of strength tests to include detailed information on storage and curing of specimens prior to testing.

4. OCSD retains the responsibility for supervising the slump testing and ultimate rejection or acceptance of any portion of the Work.

1.3 QUALITY ASSURANCE

A. Referenced Standards:

1. American Association of State Highway and Transportation Officials (AASHTO):

a. T260 Standard Method of Sampling and Testing for Total

Chloride Ion in Concrete and Concrete Raw Materials

2. American Concrete Institute (ACI):

a. 318 Building Code Requirements for Structural Concrete

b. 350 Building Code Requirements for Environmental

Engineering and Concrete Structures

3. ASTM International (ASTM):

C31 Standard Practice for Making and Curing Concrete Test

Specimens in the Field

C39 Standard Test Method for Compressive Strength of

Cylindrical Concrete Specimens

C42 Standard Test Method for Obtaining and Testing Drilled

Cores and Sawed Beams of Concrete

C138 Standard Method of Test for Unit Weight, Yield, and Air

Content (Gravimetric) of Concrete

C143 Standard Test Method for Slump of Hydraulic Cement

C172 Standard Practice for Sampling Freshly Mixed Concrete

C173 Standard Test Method for Air Content of Freshly Mixed

Concrete by the Volumetric Method

E329 Standard Specification for Agencies Engaged in

Construction Inspection and/or Testing

B. Qualifications:

1. CONTRACTOR’s Testing Agency:

a. Meeting requirements of ASTM E329.

b. Provide evidence of recent inspection by Cement and Concrete Reference Laboratory (CCRL) of National Bureau of Standards (NBS), and correction of deficiencies noted.

C. Use of Testing Agency and acceptance by ENGINEER of proposed concrete mix design shall in no way relieve CONTRACTOR of responsibility to furnish materials and construction in full compliance with Contract Documents.

1.4 DEFINITIONS

A. Testing Agency/Service Provider: An independent professional testing/inspection firm or service hired by CONTRACTOR to perform testing, inspection or analysis services as directed, and as provided in the Contract Documents.

1.5 SUBMITTALS

A. Shop Drawings:

1. Submittals shall be made in accordance with the General Requirements, Additional General Requirements, and as specified herein.

2. Product technical data including:

a. Concrete materials and concrete mix designs proposed for use.

1) Include results of all testing performed to qualify materials and to establish mix designs.

2) Place no concrete until acceptance of mix designs has been received in writing.

3) Submittal for each concrete mix design to include:

a) Sieve analysis and source of fine and coarse aggregates. b) Test for aggregate organic impurities.

c) Proportioning of all materials.

d) Type of cement with mill certificate for the cement.

e) Brand, quantity and class of fly ash proposed for use along with other submittal data as required for fly ash by Specification section

03300, Cast-in-Place Concrete.

f) Slump (under OCSD’s supervision).

g) Brand, type and quantity of air entrainment and any other proposed admixtures.

h) Shrinkage test results.

i) Total chloride ion content per cubic yard of concrete determined in accordance with AASHTO T260.

j) 28-day compression test results and any other data required by Specification section 03300, Cast-in-Place Concrete, to establish concrete mix design.

3. Certifications:

a. Testing Agency qualifications.

PART 2 - PRODUCTS (NOT USED) PART 3 - EXECUTION

3.1 TESTING SERVICES TO BE PERFORMED BY CONTRACTOR

A. The following concrete testing will be performed by CONTRACTOR’s Service

Provider:

1. Concrete strength testing:

a. Secure concrete samples in accordance with ASTM C172.

1) Obtain each sample from a different batch of concrete on a random basis, avoiding selection of test batch other than by a number selected at random before commencement of concrete placement.

b. For each strength test mold and cure four (4) cylinders from each sample in accordance with ASTM C31.

1) Record any deviations from requirements on test report.

2) Cylinder size: Per ASTM C31.

c. Field cure one cylinder for the seven- (7) day test.

1) Laboratory cure the remaining.

d. Test cylinders in accordance with ASTM C39.

1) Test two (2) cylinders at 28 days for strength test result and one (1) at seven (7) days for information.

2) Hold remaining cylinder in reserve.

e. Strength test result:

1) Average of strengths of two (2) cylinders from the same sample tested at

28 days.

2) If one (1) cylinder in a test manifests evidence of improper sampling, molding, handling, curing, or testing, discard and test reserve cylinder; average strength of remaining cylinders shall be considered strength test result.

3) Should all cylinders in a test show any of above defects, discard entire test.

f. Frequency of tests:

1) Concrete sand cement grout: One (1) strength test for each 4- hourperiod of grout placement or fraction thereof.

2) Precast concrete, concrete topping, concrete fill and lean concrete: One (1) strength test for each 10 cubic yards of each type of concrete or fraction thereof placed.

3) All other concrete:

a) One (1) strength test consisting to be taken not less than once a day, nor less than once for each 60 cubic yards or fraction thereof placed in any one (1) day.

b) If total volume of concrete on Project is such that frequency of testing required in above paragraph will provide less than five (5) strength tests for each concrete mix, tests shall then be made from at least five (5) randomly selected batches or from each batch if fewer than five (5) batches are provided.

2. Slump testing (under OCSD’s supervision):

a. Determine slump of concrete sample for each strength test.

1) Determine slump in accordance with ASTM C143.

b. If consistency of concrete appears to vary, the ENGINEER shall be authorized to require a slump test for each concrete truck.

1) This practice shall continue until the ENGINEER deems it no longer necessary.

3. Air content testing: Determine air content of concrete sample for each strength test in accordance with either ASTM C231, ASTM C173, or ASTM C138.

4. Temperature testing: Determine temperature of concrete sample for each strength test.

3.2 SAMPLING ASSISTANCE AND NOTIFICATION FOR CONTRACTOR A. To facilitate testing and inspection, perform the following:

1. Furnish any necessary labor to assist Testing Agency in obtaining and handling samples at site.

2. Provide and maintain for sole use of Testing Agency adequate facilities for safe storage and proper curing of test specimens on site for first 24 hours as required by ASTM C31.

B. Notify ENGINEER sufficiently in advance of operations (minimum of 24 hours) to allow completion of quality tests for assignment of personnel and for scheduled completion of quality tests.

3.3 ACCEPTANCE

A. Completed concrete work which meets applicable requirements will be accepted without qualification.

B. Completed concrete work which fails to meet one or more requirements but which has been repaired to bring it into compliance will be accepted without qualification.

C. Completed concrete work which fails to meet one or more requirements and which cannot be brought into compliance may be accepted or rejected as provided in these Contract Documents.

1. In this event, modifications may be required to assure that concrete work complies with requirements.

2. Modifications, as directed by ENGINEER, to be made at no additional cost to

OCSD.

D. Dimensional Tolerances:

1. Formed surfaces resulting in concrete outlines smaller than permitted by tolerances shall be considered potentially deficient in strength and subject to modifications required by ENGINEER.

2. Formed surfaces resulting in concrete outlines larger than permitted by tolerances may be rejected and excess material subject to removal.

a. If removal of excess material is permitted, accomplish in such a manner as to maintain strength of section and to meet all other applicable requirements of function and appearance.

3. Concrete members cast in wrong location may be rejected if strength, appearance or function of structure is adversely affected or misplaced items interfere with other construction.

4. Inaccurately formed concrete surfaces exceeding limits of tolerances and which are exposed to view, may be rejected.

a. Repair or remove and replace if required.

5. Finished slabs exceeding tolerances may be required to be repaired provided that strength or appearance is not adversely affected.

a. High spots may be removed with a grinder, low spots filled with a patching compound, or other remedial measures performed as permitted or required.

E. Appearance:

1. Concrete surfaces exposed to view with defects which, in opinion of ENGINEER, adversely affect appearance as required by specified finish shall be repaired by approved methods.

2. Concrete not exposed to view is not subject to rejection for defective appearance unless, in the opinion of the ENGINEER, the defects impair the strength or function of the member.

F. High Water-Cement Ratio:

1. Concrete with water in excess of the specified maximum water-cement ratio will be considered potentially deficient in durability.

2. Remove and replace concrete with high water-cement ratio or make other corrections as directed by ENGINEER.

G. Strength of Structure:

1. Strength of structure in place will be considered potentially deficient if it fails to comply with any requirements which control strength of structure, including but not necessarily limited to following:

a. Low concrete strength:

1) Test results for standard molded and cured test cylinders to be evaluated separately for each mix design.

a) Such evaluation shall be valid only if tests have been conducted in accordance with specified quality standards.

b) For evaluation of potential strength and uniformity, each mix design shall be represented by at least three (3) strength tests.

c) A strength test shall be the average of two (2) cylinders from the same sample tested at 28 days.

2) Acceptance:

a) Strength level of each specified compressive strength shall be considered satisfactory if both of the following requirements are met:

(1) Average of all sets of three (3) consecutive strength tests equal or exceed the required specified 28 day compressive strength.

(2) No individual strength test falls below the required specified 28 day compressive strength by more than 500 pounds per inch.

b. Reinforcing steel size, configuration, quantity, strength, position, or arrangement at variance with requirements in Specification Section 03200 or requirements of the Drawings or approved shop drawings.

c. Concrete which differs from required dimensions or location in such a manner as to reduce strength.

d. Curing time and procedure not meeting requirements of this Specification section.

e. Inadequate protection of concrete from extremes of temperature during early stages of hardening and strength development.

f. Mechanical injury, construction fires, accidents or premature removal of formwork likely to result in deficient strength.

g. Concrete defects such as voids, honeycomb, cold joints, spalling, cracking, etc., likely to result in deficient strength or durability.

2. Structural analysis and/or additional testing may be required when strength of structure is considered potentially deficient.

3. In-place testing of concrete may be required when strength of concrete in place is considered potentially deficient.

a. Testing by impact hammer, sonoscope, or other nondestructive device may be permitted by ENGINEER to determine relative strengths at various locations in the structure or for selecting areas to be cored.

1) Such tests shall not be used as a basis for acceptance or rejection. b. Core tests:

1) Where required, test cores will be obtained in accordance with ASTM C42.

a) If concrete in structure will be dry under service conditions, air dry cores (temperature 60 to 80 degrees F, relative humidity less than 60 percent) for seven (7) days before test then test dry.

b) If concrete in structure will be wet or subjected to high moisture atmosphere under service conditions, test cores after immersion in water for at least 40 hours and test wet.

c) Testing wet or dry to be determined by ENGINEER.

2) Three (3) representative cores may be taken from each member or area of concrete in place that is considered potentially deficient.

a) Location of cores shall be determined by ENGINEER so as least to impair strength of structure.

b) If, before testing, one (1) or more of cores shows evidence of having been damaged subsequent to or during removal from structure, damaged core shall be replaced.

3) Concrete in area represented by a core test will be considered adequate if average strength of three (3) cores is equal to at least 85 percent of specified strength and no single core is less than 75 percent of specified strength.

4) Fill core holes with nonshrink grout and finish to match surrounding surface when exposed in a finished area.

4. If core tests are inconclusive or impractical to obtain or if structural analysis does not confirm safety of structure, load tests may be required and their results evaluated in accordance with ACI 318, Chapter 20 and ACI 350.

5. Correct or replace concrete work judged inadequate by structural analysis or by results of core tests or load tests with additional construction, as directed by ENGINEER, at CONTRACTOR's expense.

6. CONTRACTOR to pay all costs incurred in providing additional testing and/or structural analysis required.