1 Assessment of Existing Concrete Structures in the Absence of Drawings Assessment of Existing Concrete Structures in the Absence of Drawings Presented by: John M. Grill, P.E. Senior Engineer Presented by: John M. Grill, P.E. Senior Engineer WDP & Associates, PC is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request. This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product. Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
Assessment Existing Concrete Structures in the absence of drawings - investigation, chloride content, resistivity, bar detection, corrosion rates, etc.
This document is posted to help you gain knowledge. Please leave a comment to let me know what you think about it! Share it to your friends and learn new things together.
Transcript
1
Assessment of Existing Concrete Structures in the
Absence of Drawings
Assessment of Existing Concrete Structures in the
Absence of Drawings
Presented by: John M. Grill, P.E.Senior Engineer
Presented by: John M. Grill, P.E.Senior Engineer
WDP & Associates, PC is a Registered Provider with The American Institute of Architects Continuing Education Systems (AIA/CES). Credit(s) earned on completion of this program will be reported to AIA/CES for AIA members. Certificates of Completion for both AIA members and non-AIA members are available upon request.
This program is registered with AIA/CES for continuing professional education. As such, it does not include content that may be deemed or construed to be an approval or endorsement by the AIA of any material of construction or any method or manner of handling, using, distributing, or dealing in any material or product.
Questions related to specific materials, methods, and services will be addressed at the conclusion of this presentation.
2
Copyright Materials
This presentation is protected by US and International Copyright laws. Reproduction, distribution, display and use of the presentation
without written permission of the speaker is prohibited.
A common problem facing design professionals involved in the
modification, repair and reuse of existing structures is how to assess the
capacity of an existing concrete structure when the original design
plans and specifications are not available. The assessment requires an
understanding of the future use, structure type and dimensions,
material properties used in the original construction, the extent of
deterioration present and current building code status of the structure.
This presentation describes methods for assessment of existing
structures with a focus on the assessment of the existing concrete
material properties and structural conditions.
3
Learning ObjectivesLearning Objectives
At the end of this program, participants will be able to:
• Identify critical structural parameters and properties that are necessary to obtain,
• Obtain familiarity with industry publications offering guidelines and techniques for obtaining information related to evaluating existing structures,
• Recognize some available test methods (destructive and nondestructive) for sampling and gathering the desired data, and
• Obtain familiarity with how these test methods are applied in practice.
MotivationMotivation
• We have a need to evaluate existing structures
– Repair/rehabilitation is needed
– Change in building use/occupancy
– Sustainable construction
• Drawings are commonly not available
– Lost over time
– Changes in ownership
4
Assessment GoalsAssessment Goals
• ACI 364.1R “Guide for Evaluation of Concrete Structures Before Rehabilitation”
• Develop as-built drawings
– Existing geometry
– Structure type
• Identify current conditions
– Deterioration
– Variations/additions to original construction
• Determine material properties
ConsiderationsConsiderations
• Structural assessment
– Current conditions
– Member geometry
– Material properties
• Analysis requirements/limitations
• Building code requirements
5
Typical Parameters to DetermineTypical Parameters to Determine
• Verification/identification of current geometry/member sizes
• Location and spacing of embedded items
– Mild reinforcing steel, post-tensioning, conduit, etc.
– Based upon evaluation of polarization resistance of reinforcing bar
– Allows measurement of rate of corrosion
29
Analysis ConcernsAnalysis Concerns
• Capacity of Existing Structure
– Account for in-situ conditions
– Account for actual material properties
– Account for construction process
• Unbraced length changes
• Shoring
–Loads imposed
• Temporary loads
• Design for “future” loads
Analysis IssuesAnalysis Issues
30
Building Code IssuesBuilding Code Issues
• Project specific assessment
• When do current code requirements have to be satisfied?
– Grandfather clause?
– Seismic requirements?
– Energy codes?
• IBC – 5% rule
Concrete Repair CodeConcrete Repair Code
• ACI 318 – Building Code Requirements for Structural Concrete
– New construction
• ICRI Concrete Repair Manual
– Collection of industry guidelines and documents
31
Concrete Repair CodeConcrete Repair Code
• ACI 562 – Code Requirements for Evaluation,Repair, and Rehabilitation of Concrete Buildings
– Final stages of development
– Expect completion in 2012
– Parallel to ACI 318 for repair
– Adopt into IEBC or IBC
• Code requirements not guidelines
– Evaluation
– Repair design
– Quality control
SummarySummary
• Existing structures commonly encountered
– Lack of design / construction documents
– Need to preserve / protect these structures
• Assessment
– Numerous methods exist
– Generally project specific
32
SummarySummary
SummarySummary
33
SummarySummary
• Existing structures commonly encountered
– Lack of design / construction documents
– Need to preserve / protect these structures
• Assessment
– Numerous methods exist
– Generally project specific
• Analysis / Codes
– More involved than new structures
– Repair code to be published in 2012
AIA Continuing Education SystemsAIA Continuing Education Systems
Learning Objectives:
• Identify critical structural parameters and properties that are necessary to obtain,
• Obtain familiarity with industry publications offering guidelines and techniques for obtaining information related to evaluating existing structures,
• Recognize some available test methods (destructive and nondestructive) for sampling and gathering the desired data, and
• Obtain familiarity with how these test methods are applied in practice.
34
Resources/ReferencesResources/References
• American Concrete Institute (ACI)
• American Society for Testing and Materials (ASTM)
• Concrete Reinforcing Steel Institute (CRSI)
• International Code Council (ICC)
• International Concrete Repair Institute (ICRI)
Questions?Questions?
This concludes this portion of thethe American Institute of Architects
Continuing Education Systems Course.
Please take a few moments to complete the Evaluation Form.
John M. Grill, P.E. | Senior Engineer703.257.9280 main | 703.257.7589 fax | [email protected]
Keith Kesner, Ph.D., P.E., S.E. | Associate203-354-4503 main | 203-354-4528 fax | [email protected]
Whitlock Dalrymple Poston & Associates, P.C.10621 Gateway Boulevard, Suite 200 | Manassas, VA 20110 | www.wdpa.com