RFI.docx

U.S. Department of State Bureau of Diplomatic Security Physical Security Division

BLAC-W

Blast Loaded Concrete Connection Anchors

June 22, 2023

1.0 SUMMARY: This document outlines a program aimed at development of evaluation and design guidance for Blast Loaded Anchors, Connections, and Welds (BLAC-W). BLAC-W is focused on pre- and post-installed concrete anchors loaded in tension, shear, and combined shear and tension for components and systems subjected to high load rates resulting from blast events. The results of this effort will serve as practical guidance for practicing engineers in improving the efficacy of blast mitigation building systems.

2.0 BACKGROUND: The Bureau of Diplomatic Security, Office of Physical Security Programs, Research and Development Branch (RD) directs and develops worldwide physical security standards, policies, procedures, and guidelines for protecting personnel, facilities, and national security information of the U.S. Department of State and foreign affairs agencies.

The recently completed work under BLAC-W involved an extensive literature survey and gap study. An advisory committee made up of subject matter experts (SME) was enlisted to review the gap study and offer recommendations for priority issues moving forward. The literature review, gap study, and SME recommendations were used to help RD establish next steps for the program. Reference 1 documents the results of that effort. This Statement of Objectives reflects the most pressing issues that require investigation for pre- and post-installed concrete anchors.

3.0 SCOPE: This effort will yield results required to provide specific guidance for evaluation and design of concrete anchors and anchor systems that are used in State facilities for blast effects mitigation. The current phase is composed of a base effort with subsequent steps to be exercised for completion of the target results. The scope has the basic components:

1) Base investigation and test design (Section 3.3)

2) Single anchor – Tension, shear, combined loading, and combined loading with nearby reinforcement.

3) Group anchors – Tension, shear, combined loading, and combined loading with nearby reinforcement.

4) Full scale blast test verification.

5) Development of a formal final report for all tasked performed. The report shall be of a quality suitable for publication.

6) Develop and submit guidance for inclusion in the Unified Facilities Criteria (UFC).

3.1 General Considerations:

The following points are applicable for all aspects of the investigation:

· Reference Information - Includes reports, methods, standards, and test results for similar geometries and load conditions regardless of effective load rates. Specifically, include quasi-static as well as high load rate results as available. Reference information shall be used for items indicated below.

· Numerical Calculations - Include numerical evaluations and predictions using classical methods and current standards. Numerical methods shall also include modelling and simulations using advanced analytical methods (e.g., finite element analysis). Factors or method modifications shall be developed that address the effects of blast loading with comparison to referenced information.

· Testing – Pre-test predictions shall be provided and used to develop specific parameters for test plans. While the planned tests may or may not include blast or shock tube test, test plans, execution, and reporting shall be in accordance with the latest version of the DOS DS RD Standard Practice for Blast Tests (Reference 2) where applicable. Post-test comparisons shall be used to confirm or refine proposed methods or factors for evaluations and design of pre- and post-installed concrete anchors.

· Load Rate – Blast events of concern result in structural loading from rest to full deformation in the range of five to fifty milliseconds. Numerical efforts and testing shall include these load rates.

· Scale – All test articles shall be at full scale in terms of anchor dimensions, spacing, edge distance, and embedment.

· Final Product – The ultimate goal of the current investigation is to develop specific guidance that may be used to design or evaluate concrete anchor connections. The guidance may be in the form of factors, equations, charts, tables, and / or computer programs. The results should support enhancement of existing standards and standard methods which currently do not properly address blast effects.

3.2 General Parameters and Condition:

The following parameters shall be included as part of the effort. Determination of the specific values and combinations of parameters shall be determined by the performer in cooperation with RD during the base investigation and test design phase discussed below in Section 3.3.

Type of anchors:

Load conditions:

Diameter of anchors: notionally ½”, ¾”, 1” Number of anchors: Single anchors and groups of anchors Embedment length: notionally 0.75x, 1.0x, 1.25x current design minimum Edge distance: notionally 0.75x, 1.0x, 1.25x current design minimum Concrete strength: notionally 3000 psi, 5000 psi Load rates to predicted capacity: quasi-static, 5 msec, 50 msec Steel reinforcement in the proximity of the anchor: include with and without Concrete condition: uncracked or cracked

The combination of test conditions shall be selected to evaluate, exercise, and/or mitigate the following limit states as indicated in Reference 1:

Tension loading of anchor

Shear loading on anchor

Combined tension and shear loading shall include consideration for all of the limit state above as applicable.

3.3 Task 1 (Base Contract) - Base Investigation and Test Design:

The base investigation shall provide design and evaluation of multiple configurations for each anchor type wherein current methods are shown to yield limiting results in terms of anchor capacity or physical dimension challenges. Proposed factors or method modifications supported by advanced numerical simulations shall be provided to demonstrate the potential benefit to be gained by the investigation.

In consideration of the very large number (tens of thousands) of possible test scenarios represented by the parameters and conditions shown in Section 3.2, a primary effort in this investigation is to reduce the required number of tests to a manageable level via an extensive test design effort. The test design process shall include use of existing pertinent data found in existing references (as cited in Reference 1 for example), numerical studies using existing design and evaluation tools, and possibly high-fidelity numerical modelling. The test design process shall yield specific test plans and test result implementation strategies for tasks listed below. The test design shall include specific information regarding specimen design, specimen construction, fixture design, load application interfaces, and reaction requirements.

Specific test plans shall be developed for Task 2. The test plans shall include test matrices with specimen specifics, fixturing, loading, and instrumentation. Numerical predictions shall be used to populate the test matrices. The test plans shall also include test facility (or facilities) information with clear demonstration of experience and capability consistent with the project requirements. Note that documentation of the test facilities’ availability and intent to support the proposed program shall be provided as part of the proposal package.

Provide preliminary test plans for Task 3 (anchor groups) and Task 4 (full scale validation). The test plans shall include test matrices with specimen specifics, fixturing, loading, and instrumentation. Numerical predictions shall be used to populate the test matrices. The test plans shall also include test facility (or facilities) information with clear demonstration of experience and capability consistent with the project requirements. Note that documentation of the test facilities’ availability and intent to support the proposed program shall be provided as part of the proposal package.

A quick look report summarizing the results of the base effort shall be provided.

3.2 Task 2 - Single Anchors (Option 1a and 1b:

3.2.a Vendor Performs all Testing Functions (Option 1a) Provide test services, coordination, witnessing, and reporting of results for the test series that was designed and planned in Task 1. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required to provide optimum correlation between predictions and test results. Use the revised results to refine the Task 3 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must be placed on load rates with quantification of load rate effects. The number of tests shall be limited to thirty (30) per anchor type for a total of ninety (90) tests (for budgeting purposes). Option 1a plans for the vendor to conduct all the testing in their test facility or subcontracted out a third-party test house.

A quick look report summarizing the results of Task 2 shall be provided along with a refined test plan for Task 3.

3.2.b Vendor Performs Testing Support and Government Conducts Testing (Option 1b) Provide test oversight services including coordination, witnessing, and analysis of results for the test series that was designed and planned in Task 1. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required to provide optimum correlation between predictions and test results. Use the revised results to refine the Task 3 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must be placed on load rates with quantification of load rate effects. The number of tests shall be limited to thirty (30) per anchor type for a total of ninety (90) tests (for budgeting purposes). Option 1b plans for the government to contract directly with the testing facility while the awardee of this contract provides all the other required support.

A quick look report summarizing the results of Task 2 shall be provided along with a refined test plan for Task 3.

3.3 Task 3 - Group Anchors (Option 2a and 2b):

3.3.a Vendor Performs all Testing Functions (Option 2a) Provide test services, coordination, witnessing, and reporting of results for the test series that was designed and planned in Task 1 and refined in Task 2. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required. Use the revised results to refine the Task 4 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must again be placed on load rates with quantification of load rate effects. At least three grouping configurations shall be included (1x2, 2x1, 2x2 as a minimum). The number of tests per anchor type may be adjusted as part to the test design process. Specifically, it is not required that the tests in this task be distributed evenly among the three anchor types. Down selecting and focusing on one or two anchor types may be acceptable for this task. The total number of tests shall be limited to eighty-one (81) for budgeting purposes. Option 2a plans for the vendor to conduct all the testing in their test facility or subcontracted out a third-party test house.

A quick look report summarizing the results of Task 3 shall be provided along with a refined test plan for Task 4.

3.3.b Vendor Performs Testing Support and Government Conducts Testing (Option 2b) Provide test services, coordination, witnessing, and reporting of results for the test series that was designed and planned in Task 1 and refined in Task 2. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required. Use the revised results to refine the Task 4 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must again be placed on load rates with quantification of load rate effects. At least three grouping configurations shall be included (1x2, 2x1, 2x2 as a minimum). The number of tests per anchor type may be adjusted as part to the test design process. Specifically, it is not required that the tests in this task be distributed evenly among the three anchor types. Down selecting and focusing on one or two anchor types may be acceptable for this task. The total number of tests shall be limited to eighty-one (81) for budgeting purposes. Option 2b plans for the government to contract directly with the testing facility while the awardee of this contract provides all the other required support.

A quick look report summarizing the results of Task 3 shall be provided along with a refined test plan for Task 4.

3.4 Task 4 – Full Scale Blast Test Verification (Option 3a and 3b)

3.4.a Vendor Performs all Testing Functions (Option 3a) Provide test services coordination, witnessing, and reporting of results for the test series that was planned in Task 1 and refined in Task 3. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required. Use the revised results to refine the Task 4 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must again be placed on load rates with quantification of load rate effects. The tested articles shall be designed to provide a variety of practical configurations wherein the predicted responses include full failure, no failure. and marginal failure. The blast loading and the resulting load rate shall be consistent with standard RD requirements. The test results shall be used to demonstrate the efficacy of the proposed evaluation and design methods. A minimum of twelve (12) configurations shall be tested. Option 3a plans for the vendor to conduct all the testing in their test facility or subcontracted out a third-party test house.

A quick look report summarizing the results of Task 4 shall be provided.

3.4.b Vendor Performs Testing Support and Government Conducts Testing (Option 3b) Provide test services coordination, witnessing, and reporting of results for the test series that was planned in Task 1 and refined in Task 3. Provide comparisons between test results and predictions. Use the results to revise factors or methods as required. Use the revised results to refine the Task 4 test plan so that it is specific and suitable for execution. While all of the issues in Section 3.2 must be considered, primary focus must again be placed on load rates with quantification of load rate effects. The tested articles shall be designed to provide a variety of practical configurations wherein the predicted responses include full failure, no failure. and marginal failure. The blast loading and the resulting load rate shall be consistent with standard RD requirements. The test results shall be used to demonstrate the efficacy of the proposed evaluation and design methods. A minimum of twelve (12) configurations shall be tested. Option 3b plans for the government to contract directly with the testing facility while the awardee of this contract provides all the other required support.

3.5 Task 5 – Formal Final Report (Option 4)

Provide a formal final report for all tasks executed. Generation of the final report shall include review and edit for technical content and report organization by a party or parties knowledgeable in the field. The report shall also be reviewed and edited for grammatical and formatting issues. The document shall be of a quality suitable for distribution to the public technical community. RD shall review and recommend possible edits for inclusion in the final report.

3.6 Task 6 – UFC Submittal and Follow-up (Option 5)

Provide specific guidance suitable for use by practicing engineers that are familiar with blast design and evaluation using the UFC. Lead or direct the process of submittal for inclusion in the UFC. All issues shall be addressed for submittal for inclusion in the UFC including any and all required supporting documents, justification, formats, and edits.

3.7 Government Test Facilities For Options 1b, 2b, and 3b)

In consideration for the extreme requirements for test facility capabilities, the option of using US Government facilities may be considered. For this purpose, Option 1b, 2b, and 3b have been included. If one or more of these options are pursued, it may be necessary for a test facility to be engaged through RD with government-to-government agreements. Any proposal involving this notion shall include written evidence of the vendor’s proposed government facilities capability, availability, and willingness to execute the required testing.

3.8 Additional Tests (option 6)

In consideration of the challenging nature of the effort, there may be justification for additional testing and / or numerical modeling to compliment the tasks above. Documentation of the cost and benefit of additional efforts may be offered as options. Any additional testing shall be proposed for each Task that includes testing: Task 2, 3, and 4.

4.0 DELIVERABLES

5.0 SECURITY:

Classification: All of the work and work product under this Statement of Objectives is unclassified. The nature of the research and development is such that the results are suitable for distribution to the general public in the form of public releasable guides, technical presentations, and support of industrial standard development.

6.0 PROPOSAL REQUIREMENTS:

Proposals shall include but not be limited to:

· Demonstration of extensive relevant experience with the technical aspects of the investigation including an understanding the practical limitations of current methods.

· A summary of the multiple configurations wherein current methods are shown to yield limiting results in terms of anchor capacity or physical dimension challenges.

· Narrative demonstrating the mitigation of technical risks associated with the investigation.

· Preliminary test plans and test matrices for Tasks 2, 3, and 4. There shall be clear documentation that the proposed tests have a very high probability of yielding appropriate results.

· Planned test execution facilities with support information regarding experience, qualifications, availability and intent to support the program. Identify specific facilities and document load application methods, load limits and corresponding load rates.

· Preliminary, conceptual, or notional specimen designs and test setups for the three test series (Tasks 2, 3, and 4)

7.0 REFERENCES:

1) Design Guidance for Blast Loaded Structural Connections, Department of State, Bureau of Diplomatic Security, Research and Development Branch, TR-20-36, February, 17, 2023.

2) DOS DS RD Standard Practice for Blast Tests, August 2022