The National Academies Press

Currently Skimming:

Pages 225-248

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 225... ... 225 A p p e n d i x F Background Cathodic protection has been used in several areas, including marine and underground structures, storage tanks, and pipelines to protect steel from corrosion (Virmani and Clemeña 1998) Read the entire page →
From page 226... ... 226 rehabilitated structure. In many cases, this level of protection can be provided with low incremental cost, as the protection can be targeted at specific areas of contamination or corrosion activity. Read the entire page →
From page 227... ... 227 Research Approach Introduction Cathodic protection is used to extend the service life of reinforced concrete structures, generally existing structures, which are chloride contaminated and are exhibiting corrosion. The intent of this research was not to test specific products, but rather to evaluate the ability of galvanic anodes in general to provide corrosion prevention or cathodic protection. Read the entire page →
From page 228... ... 228 The current for cathodic protection can be supplied to a bridge deck by one of two methods: (1) an external power source (impressed current) Read the entire page →
From page 229... ... 229 Impressed current systems can be costly and may require significant maintenance and monitoring. Galvanic systems may be easier to use; however, they provide a limited service life and level of corrosion protection. Read the entire page →
From page 230... ... 230 44 Half of the volume (0.5 yd3) was used to cast the bottom 4-in. Read the entire page →
From page 231... ... 231 • Six sacrificial anodes of each type (i.e., ordinary anodes, anodes with a larger surface [four times more zinc than ordinary anodes] , and two levels of high-voltage anode) Read the entire page →
From page 232... ... 232 Specimen Preparation The concrete slabs were prepared similar to the ones described in ASTM G109 (ASTM G109 2007a) Read the entire page →
From page 235... ... 235 as shown in Figure F.18. The same procedure was repeated three times during each wet–dry cycle. Read the entire page →
From page 236... ... 236 • The current flowing during the instant-off and -on procedure from the anodes to each pair of rebars and the corrosion potential at the location of two embedded electrodes. The experimental program started with the first half-cell potential measurement taken on September 23, 2010 (Day 0) Read the entire page →
From page 237... ... 237 labels used to identify each one of these outputs, and Figure F.23 shows the location of each monitored element on the sample. Two data analyses were conducted. Read the entire page →
From page 238... ... 238 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 Cu rr en t( m A) Time (weeks) Read the entire page →
From page 239... ... 239 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 Cu rr en t( m A) Time (weeks) Read the entire page →
From page 240... ... 240 1000 900 800 700 600 500 400 300 200 100 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 Co rr os io n Po te nt ia l( m V) Time (weeks) Read the entire page →
From page 241... ... 241 1000 900 800 700 600 500 400 300 200 100 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 Co rr os io n Po te nti al (m V) Time (weeks) Read the entire page →
From page 242... ... 242 1000 900 800 700 600 500 400 300 200 100 0 0 4 8 12 16 20 24 28 32 36 40 44 48 52 56 60 64 Co rr os io n Po te nti al (m V) Time (weeks) Read the entire page →
From page 243... ... 243 Depolarization Testing Corrosion rates were estimated through a depolarization testing procedure. Four depolarization measurements were conducted at approximately 10-week intervals. Read the entire page →
From page 244... ... 244 100.00 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 0 4 8 12 16 20 24 Co rr os io n Po te nt ia l( m V) Time (hours) Read the entire page →
From page 245... ... 245 0.00 100.00 200.00 300.00 400.00 500.00 600.00 700.00 0 4 8 12 16 20 24 Co rr os io n Po te nti al (m V) Time (hours) Read the entire page →
From page 246... ... 246 Table F.11. Variation of Corrosion Potential During Third Depolarization Period Sample Time of Measurement 0 Hour (mV) Read the entire page →
From page 247... ... 247 Table F.12. Corrosion Rate Estimation Label iappl (mA/m2) Read the entire page →
From page 248... ... 248 Figure F.36. Normalized values of half-cell potential during fourth depolarization. Read the entire page →

From page 225...

... 225 A p p e n d i x F Background Cathodic protection has been used in several areas, including marine and underground structures, storage tanks, and pipelines to protect steel from corrosion (Virmani and Clemeña 1998)