PWS_Sustained_Load_Final.pdf

Champlain Towers South Investigation:

Mechanical Properties of Concrete Under Sustained Loading Engineering Laboratory/Materials and Structural Systems Division/Infrastructure Materials Group (731.07)

General Requirements The National Construction Safety Team (NCST) investigation into the partial collapse of the Champlain Towers South requires subject matter expertise and testing of concrete materials to assist the Materials Science Project with conducting tests on concrete materials to assess the strength of the material under long-term sustained loads.

Background The National Construction Safety Team Act (“Act”), Pub. L. 107-231, codified at 15 U.S.C. 7301 et seq., was enacted to provide for the establishment of investigative teams (“Teams”) to assess building performance and emergency response and evacuation procedures in the wake of any building failure that has resulted in substantial loss of life or that posed significant potential of substantial loss of life. The purpose of investigations by Teams is to improve the safety and structural integrity of buildings in the United States. As stated in the statute, a Team shall (1) establish the likely technical cause or causes of the building failure; (2) evaluate the technical aspects of evacuation and emergency response procedures; (3) recommend, as necessary, specific improvements to building standards, codes, and practices based on the findings made pursuant to

(1) and (2); and (4) recommend any research and other appropriate actions needed to improve the structural safety of buildings and improve evacuation and emergency response procedures, based on the findings of the investigation.

On June 24th, 2021, the Champlain Towers South Condominium suffered a partial collapse. NIST sent a preliminary reconnaissance team to collect information and data related to the collapse.

Based on the recommendations of the preliminary reconnaissance team and evaluation of the criteria listed in the regulations implementing the Act, specifically in 15 CFR § 270.102, on June 30, 2021, the Director of the National Institute of Standards and Technology (NIST), United States Department of Commerce, established a Team to study the collapse of the Champlain Towers South Condominium in Surfside, FL. The Team may include members who are Federal employees and members who are not Federal employees. The Federal conflict of interest laws governs team members who are Federal employees. Team members who are not Federal employees will be Federal government contractors.

Prior work on developing a concrete material to represent materials found in the Champlain Towers South Condominium has identified new requirements necessitating the need to acquire concrete materials subject matter expertise and consultation support. The Team requires subject matter expertise to conduct static elastic modulus tests, develop a literature review on creep and shrinkage properties of concrete formulated with Miami Oolite aggregates, and to consult with NSCT contractors, as directed by NIST, on preparing concrete mixtures using materials found in South Florida.

Objectives The objective of this scope of work is to conduct mechanical property tests on concrete cylinders remaining from a prior contract (contract number: 1333ND22PNB730358), create new concrete cylinders from two concrete mixtures, and conduct additional mechanical property tests on the newly created cylinders.

Scope/General Requirements The Contractor shall provide all services detailed in Tasks 1 to 3, including providing concrete formulation expertise with materials found in South Florida. Optional Tasks 1 through 4 will be executed in accordance with FAR 52.217-7 if NIST determines it is necessary.

Task 1 – Sustained Load on > 365 d Concrete requires conducting ASTM C512 creep tests on concrete cylinders created during the trial mix design process in contract number 1333ND22PNB730358. The contractor shall perform the test continuously to monitor the applied load and displacement on the specimens and report the data at 3-month intervals.

Task 2—Sustained Loading of Evidence Specimens requires ten cylinders supplied by NIST to be tested according to ASTM C39/39M-24 - Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens and 19 cylinders supplied by NIST to be subjected to a continuously applied load until failure.

Task 3 – Shrinkage measurements of Slab Concrete require specimens to be tested according to ASTM C157. This task required materials to be prepared according to the requirements in the specific requirements section.

Optional Task 1 – Slab and Column Concrete Mixtures requires mixing two new batches of concrete to create 33 concrete cylinders per batch for mechanical property tests described in Optional Tasks 2 and 3.

Optional Task 2 – Creep Tests on 28 d Slab and Column Concrete requires the cylinders created in Task 1 to be tested according to ASTM C512 with the test starting at an age of 28 d.

Optional Task 3 – Sustained Loading of 28 d Slab and Column Concrete requires 18 cylinders to be subjected to a continuously applied load until failure.

Optional Task 4 – Creep and Shrinkage Literature Review requires the contractor to conduct a literature search for creep and shrinkage data for concrete made from materials used in the South Florida construction market.

Laboratory Requirements The Florida Department of Transportation (FDOT) shall certify the contractor's laboratory to conduct trial batch formulation and testing. The contractor shall provide a copy of the certification at the time of proposal submission.

Data Collection, Reporting, and Communication The Contractor shall be available by virtual meeting, phone, and email with NIST and NIST contractors to discuss ongoing data collection and interpretation and report preparation. NIST expects at least one virtual meeting, lasting one hour, per week during the period of performance.

Task/Specific Requirements

Task 1: Sustained Load Test – 1 year old concrete Requirement: Conduct sustained load tests on concrete materials with a nominal age of 1 year.

The contractor shall conduct a sustained load test in compression on concrete cylinders created for the trial mix design process in contract number: 1333ND22PNB730358. A total of three cylinders shall be used for each mixture, with a total of six mixtures to test. Each cylinder shall be uniaxially loaded in compression to 85 % ± 2 %, of the mixture's 90 day compression strength. The applied load and tolerance specified here are given to estimate time and resources. The NIST Technical Point of Contact (TPOC) will specify the actual applied load. NIST expects the actual applied load to be within 70 % to 90 % of the 90 day compression strength.

The uniaxial load shall be applied to the single cylinder (i.e., stacking of multiple cylinders as is done in ASTM C512 is not permitted). The load may be applied using a hydraulic system or a spring-loaded fixture described in ASTM C512. The load shall be maintained at the specified level throughout the test regardless of the loading method. The applied load shall not decrease or increase outside of the 2 % tolerance specified for each loading level.

The applied load, axial strain, and transverse strain shall be recorded continuously for the duration of the test. The logging intervals, with units of Hz, shall be logarithmically spaced with approximately 5 samples per decade. The applied load shall be measured with a load cell with a capacity no greater than twice the load applied to the cylinder determined by the NIST TPOC. Strain measurements shall be conducted with either strain gauges or linear voltage displacement transducers (LVDT).

Calibration curves for each sensor shall be provided.

Task 2: Sustained Loading of Evidence Specimens Requirement: The contractor shall conduct uniaxial compression tests and sustained loading tests on Evidence Specimens supplied by NIST.

The contractor shall test ten concrete cylinders supplied by NIST according to ASTM C39/39M-24— Standard Test Method for Compressive Strength of Cylindrical Concrete Specimens. The cylinders are nominally 3 in and 4 in diameter and are expected to have compression strengths between 2,000 psi and 8,000 psi.

The contractor shall test 19 concrete cylinders supplied by NIST, nominally 3 in or 4 in diameter.

Each cylinder shall be uniaxially loaded in compression to either 75 % ± 2 %, 85 % ± 2 %, or

90 % ± 2 % of the mixture's compression strength. The applied load intervals and tolerances specified here are given to estimate time and resources. The NIST TPOC will determine the actual applied load based on NIST’s analysis of data collected from the evidence. NIST expects the actual applied load to be within 70 % to 90 % of the 90 day compression strength. The contractor shall work with the NIST TPOC to determine the load applied to each cylinder.

The uniaxial load shall be applied to the single cylinder (i.e., stacking of multiple cylinders as is done in ASTM C512 is not permitted). The load may be applied using a hydraulic system or a spring-loaded fixture described in ASTM C512. The load shall be maintained at the specified level throughout the test regardless of the loading method. The applied load shall not decrease or increase outside of the 2 % tolerance specified for each loading level.

The applied load, axial strain, and transverse strain shall be recorded continuously for the duration of the test. The logging intervals, with units of Hz, shall be logarithmically spaced with approximately 5 samples per decade. The applied load shall be measured with a load cell with a capacity no greater than twice the load applied to the cylinder determined by the NIST TPOC. Strain measurements shall be conducted with either strain gauges or linear voltage displacement transducers (LVDT).

Calibration curves for each sensor shall be provided.

The specimens supplied by NIST are considered evidence in NIST’s NCST investigation. As such, the chain of custody requirement specified by NIST shall be maintained. Specimens shall be stored in an access-controlled manner, where only the Key Personnel have access to them until the time of testing. All fragments of broken specimens larger than 25 mm shall be retained and stored in an access-controlled manner and returned to NIST at the completion of SOW.

Duration of the sustained loading The contractor shall report to NIST TPOC the status of the sustained loading test after two weeks of sustained load. If the specimen under test has not failed, the contractor shall consult with the NIST TPOC on the next steps to be taken regarding the testing procedure. NIST may decide between two options:

1. Continue the test as is. The contractor shall continue the test under current conditions, maintaining the applied load until failure

2. Request that the load be incrementally increased until failure. The contractor shall increase the load applied to the specimen to an amount dictated by the NIST TPOC and maintain it at the dictated level for an amount of time determined by the NIST TPOC.

a. The NIST TPOC will decide on one of two options for maintaining the incremental load between load increments.

i. Hold the load at the new level until its decay rate drops below 0.5%, and then adjust the load to the next increment.

ii. Hold the load at the new level for 1 h, 2 h, 4 h, 8 h, or 24 h, then adjust the load to the next increment.

Task 3: Shrinkage Measurements of Slab Concrete The contractor shall conduct shrinkage tests following the testing program described in Table 1. The experimental design is intended to probe the shrinkage of two concrete mixtures, where each mixture has two aggregate preparation techniques and two environmental conditions.

Table 1: Experimental design of shrinkage test.

Degrees of freedom for scope of proposed shrinkage tests

2 Batches,(2 Relative Humidity exposures each).

Batch 1A & 1B Batch 2A & 2B

Batch Weights SSD Batch Weights to be provided by NIST Size of Prism 3-inch x 3-inch

Sieve-out the plus-1-inch coarse aggregate to permit 3-inch prisms.

Slump As obtained from UMinn Slab Mix Moisture conditioning of the aggregates

Water and aggregate batch weights corrected immediately prior to mixing based on measured moisture content of aggregate, per ASTM C157.

Aggregates brought to SSD immediately prior to mixing via presoaking.

Immersion cure-time after initial length measurement and before exposure to dry air

1 day limewater bath

Days of air drying at reported shrinkage

4, 7, 14, 28, 56, 90 days

2 Batches, with 2 different Relative Humidity values each.

Set 1A 50% Set 1B 80% Set 2A 50% Set 2B 80%

Task 3.1: The contractor shall prepare two concrete batches in accordance with the specifications in ASTM C192. NIST will specify the required materials, proportions, and aggregate pre-conditioning.

Task 3.2: The contractor shall conduct shrinkage tests on three prisms in accordance with ASTM C157. Tests will be conducted at two relative humidity specified by NIST.

The total experimental plan calls for shrinkage measurements of four sets of three prisms for a total of 12.

Task 3.1: Concrete Batches The contractor shall prepare two concrete batches using the formulation specified in Table 2. Each mixture shall be used to create prisms following the specification of ASTM C157. Prior to mixing, 1 in aggregates shall be sieved to permit the use of 3 in by 3 in prisms. The concretes shall be prepared using Type I/II cement and fine and coarse aggregate sources from the Miami concrete materials market. The coarse aggregate shall be Miami Oolite #57 sieve size. The concrete-making materials for the trial batches, including cement, aggregates, and admixtures, shall be provided to the contractor by NIST.

Table 2: Batch weights for the concrete mixture. All weights are specified in lbs/yd3.

w/c Cement Water Coarse Aggregates

Crusher Screens

Fine River Sand

Total Batch Weight

0.6 490 294 1860 684 456 3739

Batch 1 shall be prepared using the proportions in Table 2 and the specifications of ASTM C192. Per ASTM C157, water and aggregate batch weights are to be corrected immediately prior to mixing based on the measured moisture content of the aggregate.

Bach 2 shall be prepared using the proportions in Table 2 and the specifications of ASTM C192. The aggregates are to be brought to SSD immediately prior to mixing via a presoaking procedure specified by NIST.

All prisms shall be de-molded after 1 day, and their initial lengths obtained in accordance with ASTM C157. The prisms shall be exposed to a limewater bath for 1 day before exposure to the shrinkage environment.

Task 3.2: ASTM C157 Shrinkage Measurements The contractor shall conduct shrinkage measurements according to ASTM C157 on 12 3 in by 3 in concrete prisms. The first set of prisms shall be created from batch 1 in Task 1. Of the 6, three prisms, Set 1A, shall be exposed to a relative humidity of 50 % during the shrinkage test. The second set, Set 1B, of three prisms shall be exposed to a relative humidity of 80 % during the shrinkage tests.

The second set of six prisms shall be created from batch 2 in Task 1. Three prims from batch two, Set 2A, shall be exposed to a relative humidity of 50 % during the shrinkage test. The second set, Set 2B, shall be exposed to a relative humidity of 80 % during the shrinkage tests.

The shrinkage tests for Set 1A, 1B, 2A, and 2B shall be run for 90 days following ASTM C157.

The contractor shall prepare a report on the results of the shrinkage measurements obtained in Task

2. The report shall contain details on the mixing procedure, including the aggregate preparation technique, the processed shrinkage data for each set, the raw shrinkage data for each set, and recommendations for implementing this testing technique at NIST.

Optional Task 1: Concrete Mixing and Cylinder Casting Requirement: Create concrete cylinders for elastic modulus, creep, and sustained loading tests described in Optional Tasks 2 and 3.

The contractor shall prepare two concrete mixtures using the formulation specified in Table 3. Each mixture shall create 33 concrete cylinder specimens with nominal dimensions of 4 inches in diameter by 8 inches long.

Table 3: Batch weights for concrete mixtures A and B. All weights are specified in lbs/yd3.

w/c Cement Water Coarse Aggregates

Crusher Screens

Fine River Sand

Total Batch Weight

Mix A 0.5 588 294 1860 636 424 3802

Mix B 0.6 490 294 1860 684 456 3739

The trial batches shall be created in an FDOT-certified concrete laboratory following ACI 301-20. The concrete-making materials for the trial batches, including cement, aggregates, and admixtures, shall be provided to the contractor by NIST. The contractor shall supply water. At the time of trial batch creation, plastic concrete physical testing shall include the following:

• The temperature following ASTM C1064

• Air content following ASTM C231

• Slump following ASTM C143

• Unit weight following ASTM C138

All concrete cylinders shall remain sealed in the molds for 24 hours at a temperature of 70 °F ± 10 °F. After 24 hours, the molds shall be removed, and the cylinders shall remain immersed in a limewater bath maintained at 73 °F ± 3 °F until the time of testing.

Optional Task 2: ASTM C512 Concrete Creep Tests Requirement: Conduct creep tests on concrete cylinders created in Optional Task 1.

The contractor shall conduct the ASTM C125/C512-M - Standard Test Method for Creep of Concrete in Compression on concrete cylinders created in Optional Task 1 with a nominal 28 day age. Three cylinders shall be tested per batch at 40 % f’c. The tests shall run continuously for at least 365 days after the start of the test. Load and displacement data shall be logged continuously throughout the duration of the tests. Results shall be reported at 3 months, 6 months, 9 months, and 12 months of test duration. Data shall be recorded and reported to NIST at each reporting interval.

Optional Task 3: Sustained Loading of 28 d Slab and Column Concrete Requirement: The contractor shall conduct a sustained loading test on concrete cylinders created in Optional Task 1.

The contractor shall test to failure three concrete cylinders per batch of concrete created in Optional Task 1 per applied loading case. Each cylinder shall be uniaxially loaded in compression to either 75 % ± 2 %, 85 % ± 2 %, or 90 % ± 2 % of the compression strength of the mixture. The compression strength of the mixture shall be defined as the average of three ASTM C39 compression breaks at 28 d age. Each cylinder shall be maintained at the applied load continuously until failure. The applied load, axial strain, and transverse strain shall be continuously measured throughout the test.

The uniaxial load shall be applied to the single cylinder (i.e., stacking of multiple cylinders as is done in ASTM C512 is not permitted). The load may be applied using a hydraulic system or a spring-loaded fixture described in ASTM C512. The load shall be maintained at the specified level throughout the test regardless of the loading method. The applied load shall not decrease or increase outside of the 2 % tolerance specified for each loading level.

The applied load, axial strain, and transverse strain shall be recorded continuously for the duration of the test. The logging intervals, with units of Hz, shall be logarithmically spaced with approximately 5 samples per decade. The applied load shall be measured with a load cell with a capacity no greater than twice the load calculated from ASTM C39 compression strength measurements. Strain measurements shall be conducted with either strain gauges or linear voltage displacement transducers (LVDT). Calibration curves for each sensor shall be provided.

Duration of the sustained loading The contractor shall report to NIST TPOC the status of the sustained loading test after two weeks of sustained load. If the specimen under test has not failed, the contractor shall consult with the NIST TPOC on the next steps to be taken regarding the testing procedure. NIST may decide between two options:

3. Continue the test as is. The contractor shall continue the test under current conditions, maintaining the applied load until failure

4. Request that the load be incrementally increased until failure. The contractor shall increase the load applied to the specimen to an amount dictated by the NIST TPOC and maintain it at the dictated level for an amount of time determined by the NIST TPOC.

a. The NIST TPOC will decide on one of two options for maintaining the incremental load between load increments.

i. Hold the load at the new level until its decay rate drops below 0.5%, and then adjust the load to the next increment.

ii. Hold the load at the new level for 1 h, 2 h, 4 h, 8 h, or 24 h, then adjust the load to the next increment.

Optional Task 4: Creep and Shrinkage Literature Review Requirement: Compile data on creep and shrinkage measurements of concretes made with Miami limestone aggregates.

In Optional Task 4, a literature review shall be conducted and presented to the NCST investigation on the creep and shrinkage properties of concrete materials. The literature review shall be focused on concrete created using Miami Oolite aggregates with fine aggregates comprised of aggregate screens and natural river sand. The literature review aims to compile creep and shrinkage data for modeling the structural response of reinforced concrete elements. The contractor shall compile a list of references, summarize the findings of the references, and compile the data in the references into a data set. The contractor shall also provide subject matter expertise and advise the NCST on appropriately using the data in structural modeling.

NSCT investigation contractors require consultation from a subject matter expert on mixing concrete using materials found in the South Florida construction market. The contractor shall, at NIST direction, advise NSCT contractors on the best practices and procedures that should be followed to prepare concrete using Miami Oolite aggregates. The contractor shall hall be available for virtual meetings, phone calls, and emails to answer questions as required by NIST and the NCST.

The contractor shall compile data on creep and shrinkage measurements of concretes made with Miami limestone aggregates. The data set shall report shrinkage and creep coefficients and contain information on the volume fraction of coarse aggregates, fine aggregates, water, cement, and air.

The data set will also include information on aggregate mineralogy, size, and shape for coarse and fine aggregates. The data set shall be reported in CSV form and contain the DOI of the manuscript from which the data was collected.

Deliverables Desired Deliverables

Desired Deliverable Associated Task

Required Service Performance Standard Monitoring Method

0. Kick-off Meeting All Consulting Attendance of virtual meeting

Contracting Officer’s Representative (COR) will be in contact with Contractor

1. Task 1 Sustained loading test results on > 365 day old concrete

Task 1 Material Testing Sustained Loading Procedure

Contracting Officer’s Representative (COR) will be in contact with Contractor. Attendance by NIST TPOC and contractor Key Personnel

2. Task 2 ASTM C39 Test Results

Task 2 Material Testing ASTM C39/C39M-24 COR Review of data submitted by contractor

3. Task 2 Sustained loading test results on evidence

Task 2 Material testing Sustained Loading Procedure

Contracting Officer’s Representative (COR) will be in contact with Contractor. Attendance by NIST TPOC and contractor Key Personnel

4. Task 3 Kickoff Meeting to discuss mixing and specimen storage plan.

Task 3 Consulting Review of testing plan

ASTM C157

Contracting Officer’s Representative (COR) will be in contact with Contractor. Attendance by NIST TPOC and contractor Key Personnel

5. Task 3 Concrete Mixing Report

Task 3 Material Testing ACI 301-20 COR Review of data submitted by contractor

6. Task 3 Shrinkage test results reporting intervals

Task 3 Material Testing ASTM C157 Contracting Officer’s Representative (COR) will be in contact with Contractor. Attendance by NIST TPOC and contractor Key Personnel

1. 66 concrete cylinders created from two batches of concrete

Optional Task 1

Material Testing Fresh concrete data and batch ticket for both concrete mixtures

COR Review of data submitted by contractor

2. Start Optional Task 2 ASTM C512 tests

Optional Task 2

Material Testing ASTM C512/C512M-15 Meeting with COR to review test start.

3. 3 months Report containing the required data specified in ASTM C512 and Task 2.

Optional Task 2

Material Testing ASTM C512/C512M-15 COR Review of data submitted by contractor

4. 9 months Report containing the required data specified in ASTM C512 and Task 2.

Optional Task 2

Material Testing ASTM C512/C512M-15 COR Review of data submitted by contractor

5. 9 months Report containing the required data specified in ASTM C512 and Task 2.

Optional Task 2

Material Testing ASTM C512/C512M-15 COR Review of data submitted by contractor

6. 12 months Report containing the required data specified in ASTM C512 and Task 2.

Optional Task 2

Material Testing ASTM C512/C512M-15 COR Review of data submitted by contractor

7. Optional Task 3 Kickoff Meeting to determine applied loads to specimens

Optional Task 3

Consulting Sustained Loading Procedure

Contracting Officer’s Representative (COR) will be in contact with Contractor. Attendance by NIST TPOC and contractor Key Personnel

8. Creep and Shrinkage data set

Optional Task 4

Consulting and Literature Review

Review of references cited to create data set

Bi-Weekly meetings with COR discussing creep and shrinkage properties of concrete. Meetings shall define the scope of the literature review and where to focus efforts.

Deliverable Schedule Deliverable Description Quantity/Media Date Required

0 Kick-off Meeting Virtual Meeting Within one week of the award

1 Task 1 Sustained loading test results on > 365 day old concrete

Starts withing 1 week of award, report due two weeks after specimen failure

2 Task 2 ASTM C39 Test Results Report: MS Word, Data set: Excel, CSV.

Within one week of the award

3 Task 2 Sustained loading test results on evidence Report: MS Word, Data set: Excel, CSV.

Starts withing 3 weeks of award, report due two weeks after specimen failure

4 Task 3 Kickoff Meeting to discuss mixing and specimen storage plan.

Virtual Meeting Within one week of the award

5 Task 3 Concrete Mixing Report Report: MS Word, Data set: Excel, CSV.

Within 5 weeks of the award

6 Task 3 Shrinkage test results reporting intervals Report: MS Word, Data set: Excel, CSV.

Starts within one week of award with data reports at due to COR at 4 d, 7 d, 14 d, 28 d, 56 d, 90 d after test start.

Optional 1 Optional Task 1. 66 concrete cylinders created from two batches of concrete

Report: MS Word, Data set: Excel, CSV.

Mixing to begin within one week after exercising option, report withing 5 weeks of award

Optional 2 Optional Task 2. Start ASTM C512 tests Report: MS Word, Data set: Excel, CSV.

Within 4 weeks after exercising option.

Optional 3 Optional Task 2. 3 months Report containing the required data specified in ASTM C512 and Optional Task 1.

Report: MS Word, Data set: Excel, CSV.

Within 18 weeks after exercising option.

Optional 4 Optional Task 2. 6 months Report containing the required data specified in ASTM C512 and OPtional Task 1.

Report: MS Word, Data set: Excel, CSV.

Within 30 weeks after exercising option.

Optional 5 Optional Task 2. 9 months Report containing the required data specified in ASTM C512 and Optional Task 1.

Report: MS Word, Data set: Excel, CSV.

Within 42 weeks after exercising option.

Optional 6 Optional Task 2. 12 months Report containing the required data specified in ASTM C512 and Optional Task 1.

Report: MS Word, Data set: Excel, CSV.

Withing 60 weeks after exercising option.

Optional 7 Optional Task 3. Kickoff Meeting to determine applied loads to specimens

Report: MS Word, Data set: Excel, CSV.

Within 4 weeks after exercising option.

Optional 8 Optional Task 4. Creep and Shrinkage data set Within 36 weeks after exercising option.

Deliverable Schedule Gantt Chart – Tasks 1 to 3 The deliverables listed above shall be transmitted to the NIST COR at the times indicated below

Deliverable Due Date: Weeks Past Award 1 2 3 4 5 6 7 8 12 18 24 30 36 42 48 54 60 66

1. Task 1 Sustained loading test results on > 365 day old concrete Task 1 tests run until failure. Report due 2 weeks after specimen failure

2. Task 2 ASTM C39 Test Results

3. Task 2 Sustained loading tests on evidence Task 5 tests run until failure. Report due 2 weeks after specimen failure

4. Task 3 Kickoff Meeting to discuss mixing and specimen storage plan.

5. Task 3 Concrete Mixing Report

6. Task 3 report on shrinkage test Results Task 6: Shrinkage Tests with 4, 7, 14, 28, 56, 90 reports

Deliverable Schedule Gantt Chart – Optional Tasks 1 to 4

Deliverable Due Date: Weeks execution of Optional Task 1 2 3 4 5 6 7 8 12 18 24 30 36 42 48 54 60 66

1. 66 concrete cylinders created from two batches of concrete 28 d Curing

2. Start Optional Task 2 ASTM C512 tests

3. 3 months Report containing the required data specified in ASTM C512 and T Optional Task 2. Optional Task 2: 0 to 3 months of Creep

4. 6 months Report containing the required data specified in ASTM C512 and Optional Task 2. Task 3: 3 to 6 months creep

5. 9 months Report containing the required data specified in ASTM C512 and Optional Task 2. Task 3: 6 to 9 months creep

6. 12 months Report containing the required data specified in ASTM C512 and Optional Task 2. Task 2: 9 to 12 months creep

7. Optional Task 3 Kickoff Meeting to determine applied loads to specimens Optional Task 3 tests run until failure. Report due 2 weeks after specimen failure

8. Optional Task 4 Creep and Shrinkage data set

Government-Furnished Property, Materials, Equipment, or Information NIST will provide the contractor with all concrete-making materials required to develop the trial batches, except water. NIST will provide the contractor with the necessary information on the probable mixture proportions, targeted compression strengths, water-to-cement ratios, and targeted concrete slump.

NIST will provide evidence specimens to complete the deliverables in Task 2.

Other Unique Requirements:

Key Personnel Requirements The Contractor shall provide a minimum of one lead engineer or scientist to serve as a concrete materials expert, meeting the following criteria:

Minimum Education: Ph.D. degree from an accredited college or university in Material Science/Civil Engineering

Responsibilities: Applies technical knowledge and judgment in a scientific or another technical field in relevant engineering principles and practices as required for technically complex assignments. Develops solutions to difficult problems. Generates concepts as evidenced by product or process improvement. Uses engineering/scientific tools to integrate requirements and solve technical problems. Utilizes tools, techniques, processes, and/or facilities, such as state-of-the-art simulation environments, laboratories, and test facilities. Contributes to the technical planning.

Minimum Experience: The contractor shall have experience mixing concrete with materials found in South Florida, specifically experience with concrete created using Miami limestone (lime rock).

The contractor shall be familiar with the concrete mixing and design guidelines specified by the Florida Department of Transportation (FDOT) and demonstrate prior experience in mixing and formulating concrete for FDOT.

The contractor shall submit records of prior work performed for FDOT. These records can be in the form of a letter of reference, a report, or a scientific paper. The records shall indicate the scope of the work performed, the methods utilized to complete the work, and compliance with FDOT concrete formulation and mixing procedures.

Laboratory Certifications The laboratory conducting the trial batching shall be certified by FDOT to evaluate concrete materials.

Data Reporting and Sharing The Contractor shall retain all raw and processed data collected during laboratory studies and report the data to NIST and the NCST investigation team. The Contractor shall make all raw and processed data available to NIST contractors and members of the NCST investigation.

Raw data shall include, but is not limited to, data recorded, copied, or saved from instruments, laboratory notebooks, pictures, and simulation outputs. Processed data shall include, but is not limited to, data generated from raw data, including, reports, figures, graphics, interpretations, and calculations.

Preservation of Physical Evidence The Contractor shall preserve all physical evidence received from NIST and the NCST investigation in a manner consistent with the investigative purposes of the evidence. NIST and the Contractor shall consult on appropriate storage procedures. The Contractor shall not discard any material evidence, including the material that remains after a test, unless authorized to do so by NIST or the NCST investigation team.

Travel Travel is not required.

Place of Performance The primary place of performance is expected to be the Contractor’s facility.

Period of Performance The contract shall have a period of performance of 12 months.

Optional Task 4: Creep and Shrinkage Literature Review