PART 3 - EXECUTION
3.1 TESTING AND INSPECTION
A. The Testing Laboratory shall maintain and distribute continuous record of the quality of materials and workmanship under its control, and certify that such materials and workmanship meet the contract requirements.
B. The inspection and control shall be performed under the direction of the Structural Engineer of Record.
C. The duties of the Testing Laboratory shall include:
1. Tests and certification of materials or components designated to be tested at place of fabrication or at the job site.
2. Supervision and certification of fabrication and erection of materials designated to be inspected.
3. Acceptance testing of concrete design mixes. 4. Submission of reports:
a. Copies of each report of plant and field inspection shall be made and distributed within 3 days. Copies of each report of tests shall be distributed within 2 days of the performance of tests. Results of tests showing non- conformance to contract requirements shall be advised to the Architect and General Contractor by phone on the same day.
b. Distribution of one copy of each report shall be as follows: Owner, Architect, Structural Engineer, General Contractor, Inspectional Services. c. All reports shall include accurate and unambiguous descriptions of the source
of the materials and their location in the structure.
3.2 QUALITY CONTROL FOR CONCRETE
A. Provide inspection and testing at the batching plant once at the start of the project and periodically thereafter, and at the project whenever structural concrete is placed. Provide testing in accordance with the approved referenced standard methods.
B. Batching Plant Inspection: Make verification of calibration of weighing equipment, measuring equipment and timing devices. Make observation of mixing equipment and its operation, methods used for measuring and changing ingredients and water into mixing equipment. Make observations of truck mixers, agitators, or other concrete transportation equipment. Verify that ingredients for concrete are from the sources identified in the approved design mixes and that they are properly stored at the plant. Make gradation and moisture tests of aggregates. Determine and record the actual batched weights and water-cement ratio used; verify that such weights and ratio conform to the weights and proportions required by the approved design mixes, adjusted for actual moisture content and gradation of aggregates.
C. Field Tests: Obtain samples of concrete at the project and make quality control tests during placing operations, including slump tests, air content tests, density tests, air temperature and concrete temperature for all concrete, and sets of cylinders for compressive tests. Cylinders required by the Contractor for stripping purposes are excluded from these quality control requirements.
NANTUCKET HIGH SCHOOL BID SET
AUTO BODY SHOP RENOVATION 06/08/16
NANTUCKET PUBLIC SCHOOLS NANTUCKET, MA
16055 QUALITY CONTROL AND TESTING SERVICES 014320 - 6
D. Slump tests shall be made from each load of concrete; if concrete is pumped, slump tests shall be taken at point of discharge. When air entrainment is required by the approved design mix, air content tests shall be made from each load of concrete. If the measured density of any concrete, or the measured slump of any concrete, or the air content of air entrained concrete, falls outside the limits of the approved design mix, a check test shall be made immediately on another portion of the same load. In the event of a second failure, the concrete shall be considered to have failed to meet the requirements of the approved design mix, and shall not be used on the project.
E. Test Cylinder Sets: Make sets of 4 cylinders (6" dia. x 12" long) for each class of concrete on each day that it is placed. Take one set of cylinders, directly from the mixer, or point of discharge if pumped, for each 50 cubic yards or fraction thereof, or once per day for each design mix. The tests are intended to ensure that the concrete meets the specified requirements, with particular regard to 28 day strength. Identify cylinder sets by date, concrete class, concrete delivery ticket and location of placement in the project
F. Field Curing: Provide all facilities for making and transporting the test cylinders. Utilize the curing box provided by the Contractor for storage of cylinders in the field. The box shall be heated as required to maintain curing conditions consistent with the curing of the project concrete. During hot weather, test cylinders shall be covered immediately with damp burlap and cooled or stored otherwise as required to maintain curing conditions consistent with the curing of the project concrete. The box shall be located in an area free from vibration caused by construction operations and by off-site causes. Cylinders shall remain in the curing box until ready for transportation to the laboratory but not less than 24 hours.
G. Cylinder Tests: Transport the cylinders to the laboratory in a vertical position. Store and cure the cylinders under controlled conditions until time of testing. Make compressive strength tests of one cylinder of each set at 7 days and of the other three cylinders of each set at 28 days. If the first two cylinders tested at 28 days show strengths less than 85 percent of the specified value, the third cylinder shall not be tested as directed by the Architect. The testing of each set of three test cylinders at 28 days shall be considered as one strength test. The strength of such test shall be the average of the breaking strengths of the three cylinders comprising the test except that, if one of the specimens shall show manifest evidence of improper sampling, molding, handling, or testing, it shall be discarded and the remaining two averaged. If the first two cylinders tested at 28 days show strengths less than 85 percent of the specified value, the third cylinder shall not be tested at 28 days but shall be kept available for later testing as directed by the Architect.
H. Concrete Aggregate Testing: At start of project and whenever a change in source of characteristics occurs, provide standard acceptance tests of fine and coarse aggregates for quality and determination of physical properties. Tests shall include sieve analysis, specify gravity, absorption tests, silt content, soundness and organic content.
I. Verification and Evaluation of Mix Designs: Verify and evaluate that Contractor's mix designs, pumped or otherwise, are in accordance with Project Specifications.
J. Reinforcement and Formwork: Inspect reinforcement for surface cleanliness, accessories, clearances, sizes and spacing, etc. Inspect formwork for tightness, adequacy, surface quality and cleanliness.
K. Concrete Placement: Inspect methods of discharge, transport, placement, consolidation and finishing.
L. Grout and Grouting: Examine and ascertain that the materials used for grouting conform to the Specifications. Check grouting operations for conformance with the Specifications and with the manufacturer's recommendations for use. Check that the grout fills all voids and spaces which are required to be grouted.
M. Grout Compressive Tests: Grout shall be tested for compressive strength. Provide a top plate fastened to the top of the mold to confine the mortar and simulate in-place conditions. Nine 2" x 2" cubes shall be taken in the field for each set. Three cubes shall be taken on each day that each strength class of grout is being placed.
3.3 REPAIR AND PROTECTION
A. General: Upon completion of inspection, testing, sample taking and similar services, repair damaged construction and restore substrates and finishes. Comply with Contract Document requirements for "Cutting and Patching."
B. Protect construction exposed by or for quality-control service activities, and protect repaired construction.
C. Repair and protection is Contractor's responsibility, regardless of the assignment of responsibility for inspection, testing, or similar services.
NANTUCKET HIGH SCHOOL BID SET
AUTO BODY SHOP RENOVATION 06/08/16
NANTUCKET PUBLIC SCHOOLS NANTUCKET, MA
16055 QUALITY CONTROL AND TESTING SERVICES 014320 - 8
SECTION 015000