1 / 15

Severud Associates Consulting Engineers PC

Severud Associates Consulting Engineers PC. Museum of the American Indian Washington, D.C. Yale University Ingalls Hockey Rink New Haven, CT. Eventi Hotel 839 6 th Avenue, New York, NY. The US Mission to the UN New York, NY. US Airways Terminal, Philadelphia International Airport.

Télécharger la présentation

Severud Associates Consulting Engineers PC

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript


  1. Severud Associates Consulting Engineers PC Museum of the American Indian Washington, D.C. Yale University Ingalls Hockey Rink New Haven, CT Eventi Hotel 839 6th Avenue, New York, NY The US Mission to the UN New York, NY • US Airways Terminal, • Philadelphia International Airport

  2. Severud Associates Consulting Engineers PC Jefferson National Expansion Memorial Saint Louis, MO The Times Square Edition 701 7th Avenue, New York, NY • Bank of America Tower • New York, NY

  3. Typical Concrete Strength and Stiffness Specs for High Rise (Over 500 feet) in NYC • Spec concrete strength 6 ksito 12 ksi • Actual concrete strength 6 ksito 19 ksi • Specified E value 4.7Mpsi to 6.6Mpsi • Actual E value 8Mpsi max • No. concrete mixes 10 - 20 • w/c ratio 0.29 to 0.35 (verified by microwave test)

  4. Concrete Placement Rules • 95% max water content added at the plant. Max 5% water available for addition at the site. • 5% held water added on site only to raise the slump of the concrete. • Superplasticizer to be made available on site during all concrete placing operations, for re-dosage as required. All trucks delivering to the site shall be supplied with a re-dosage chart. • All concrete trucks arriving to the jobsite will have a computerized batch ticket to be given to the inspector for review prior to pouring concrete. • The batch ticket must indicate truck number, total batch size, strength in psi, time of discharge, amounts of materials added at the plant, percentage of moisture in the aggregate. • Trucks arriving on site without the computerized batch ticket shall be rejected.

  5. Concrete Placement Rules (cont.) • Pre-approved design mixes and admixtures only. A pre-approved mix is defined as one having the exact same constituent proportions and constituent sources. Any truck arriving on site with a mix or admixture that is different than the approved design mixes shall be rejected. • Pour time limit = 90 minutes after leaving plant, with a possible extension to 120 minutes (pending the temperature of the concrete). • However, if the mix is provided with a hydration control admixture that has been pre-approved, this time limit may exceed 120 minutes. • Lab shall measure concrete temperature after 90 minutes. • 700F < Temperature < 900F : Inspector’s or Engineer’s call • Temperature > 950F : concrete is rejected regardless of mix time • Temperature < 500F : concrete is rejected regardless of mix time

  6. Concrete Placement Rules • Time > 120 minutes : concrete is rejected (unless the mix is provided with a pre-approved hydration control admixture) • Slump exceeds max value shown on design mix (with tolerances): concrete is rejected • No concrete placement without both Severud and the testing lab present • An insulated coring box with sufficient room to place all the required samples shall be provided on site. • A microwave oven will be provided at the site to verify the moisture content in the concrete in accordance with the specifications. • Slump tests for every 50 yards of concrete placed, and at any time upon a request from Severud, at the point of discharge (at the truck). • The contractor will be responsible for delivering the required samples from the point of placement to the concrete inspector on request every 150 cubic yards if concrete is placed using a pump.

  7. Typical 8,000psi Mix – Vertical Elements

  8. Typical 8,000psi Mix – Vertical Elements

  9. Typical 10,000psi Mix – Vertical Elements

  10. Typical 10,000psi Mix – Vertical Elements

  11. Typical 12,000psi Mix – Vertical Elements

  12. Typical 12,000psi Mix – Vertical Elements

  13. Modulus E Chart for Test Cylinders Modulus of Elasticity and Poisson’s Ratio: ASTM C469 / C469M–14

  14. Microwave Oven Testing • Used to test water content and water cementitious ratio of discharged concrete at the site • AASHTO T318 for Guidelines • One test per every five trucks (or fifty yards), typically • Used for verification of water content, not for rejection* • * if it is a frequent issue, rejection and remediation will be required Microwave Test Equipment (Courtesy of National Concrete Pavement Technology Center)

  15. THANK YOU

More Related