Details:

Alternative Title:
Part 1 : description of potential defects.
Creators:
Kaiser, Henning ; Karbhari, Vistasp M.
Kaiser, Henning ; Karbhari, Vistasp M. Less -
Corporate Contributors:
Oregon. Department of Transportation
Subject/TRT Terms:
[+]
Concrete Structures Defects Fibers Monitoring Prefabricated Structures Quality Assurance Rehabilitation (Maintenance) Resins Structural Rehabilitation Measures Structures
Resource Type:
Tech Report
Corporate Publisher:
University of California, San Diego.
Abstract:
For concrete rehabilitation, application of fiber reinforced polymer composites continues to grow in popularity. However, performance and expected lifetime of such rehabilitation measures are greatly depending on quality of workmanship and are jeopardized by a wide range of material defects. Prior to installation, potential defects must be known and evaluated upon their likeliness of occurrence during the individual project. Special attention should be paid to storage, handling and preparation of incoming materials as well as site preparation. Apart from a well-coordinated installation process, a suitable environment for work with composite materials must be provided. Although a successfully performed installation procedure with low defect occurrence would yield a fairly long service life, harsh environmental conditions can cause rapid deterioration of most composite strengthening systems. Hence, quality monitoring must be performed beyond the installation stage and continued throughout the lifetime of a rehabilitated structure. Tables 4-1 through 4-4 summarize all previously discussed defects by their initiating phase. Furthermore, possible potential effects are listed.

While the types of defects to be encountered are mostly known, information on defect criticality and their effect on short/long-term structural performance remain widely unknown. Nevertheless, previous research has shown that defects like localized porosity, surface scratches or single broken fibers do not have a significant effect on material performance. Instead, they should be considered a material property that must be accounted for, especially if processing of composites is performed manually. Assessment of criticality of such “normal” defects will therefore be done on the basis of previous research results, whereas different techniques must be employed to characterize and quantify the effect of defects such as severe debonding, delamination, large voids, tow breakage or moisture accumulation, to name only a few. Thus, the need for further investigation in this field arises.


Format:
PDF
Funding:
18347
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:496128dd9edec99c5f78d3b8454c6af01f40501e7b91f3770e73668a74683733
Download URL:
https://rosap.ntl.bts.gov/view/dot/22816/dot_22816_DS1.pdf
File Type:

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