Skip to main content

Currently Skimming:


Pages 9-25

The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.


From page 9...
... 9Findings of Literature Review A literature search was conducted to locate published information on durability studies of detectable warning systems, including tests performed and results obtained. The literature generally took one of the following forms: syntheses and summaries, reports of field trials, reports of property-specific laboratory or field tests, and laboratory testing protocols.
From page 10...
... 10 Study Location System Types Type of Degradation Listed Source of Degradation New Hampshire (Boisvert, 2003) Surface-applied single domes, stamped concrete, polymer concrete, rigid polymer composite panel, flexible polymer mat, brick paver, precast concrete paver Damaged or missing domes Snow removal (study specially tested snow removal durability)
From page 11...
... (WisDOT) indicated that the State of Wisconsin has developed a snowplow test in which a detectable warning panel is placed in a plywood jig and passed over 50 times with a truck-mounted plow.
From page 12...
... Nevada, and Washington. The respondents who list ultraviolet/ sun exposure as a key deterioration mechanism are from all over the country, including areas, such as New Jersey, that experience cold winters.
From page 13...
... has requirements for brick pavers including water absorption, freeze/thaw resistance and general conformance to ASTM C 902 Standard Specification for Pedestrian and Light Traffic Paving Brick Class SX, Type I Discussion of Findings of Literature Review and Survey The findings of the literature review and survey were summarized in terms of the deterioration mechanism judged significant to the durability of detectable warning systems and in terms of the range of detectable warning system products that the test protocol may be used to evaluate.
From page 14...
... (methods of attachment) as well as the types of materials used in detectable warning systems.
From page 15...
... The protocol tests detectable warning systems installed in or applied to concrete slabs. Two types of test methods are used.
From page 16...
... The proposed method consists of a freeze/thaw test where the concrete/detectable warning system samples are ponded or submerged in sodium chloride solution and subjected to repeated freezing and thawing cycles. The entire top surface of the specimen is ponded or submersed for the full duration of the test, to allow water to penetrate around any attachments, gaps, joints, or cracks in the detectable warning system/concrete composite system.
From page 17...
... for the cold exposure category. This heating must be performed within a set time period.
From page 18...
... 18 foam attached to a rigid plate, is translated across the surface of the system by a hand-operated dolly and cable system. The foam allows the sandpaper to partially conform to the tops of the domes.
From page 19...
... accommodate slight differences in dome dimensions and operator uncertainty in measurement. Measuring the dome diameter at the base with calipers is shown in Figure 9.
From page 20...
... This test method has been adapted to test the adhesion of surface-applied single domes to the concrete surface. If coating is present on the top of the domes, the domes are tested with the coating in place and with the coating removed with abrasive paper to isolate the dome/substrate interface.
From page 21...
... system. The energy of impact is controlled by a combination of impactor mass and drop height.
From page 22...
... Difficulties in obtaining repeatable results, representative of the full system response, prevented finalization of a method. The data for the bond testing varied significantly between the five different systems included in the development, as well as within a single material when repeated tests were performed.
From page 23...
... confidently predict a specific service life under particular site conditions. Variability in field installation, field service conditions and interaction of the effects of environmental exposure creates additional challenges in predicting service life of detectable warning systems.
From page 24...
... performance ratings are not assigned using the same incremental scale. Rather, the evaluation is set up as a pass/fail result, with the test result being assigned either a 2 (likely to produce acceptable performance)
From page 25...
... and importance factors have been selected to represent an urban, high-traffic setting in an environment where freezing and thawing is expected. While Table 9 shows a hypothetical set of results, the following discussion provides an example of how such results might be interpreted.

Key Terms



This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More information on Chapter Skim is available.