Comp CPC 18 Measurement of hardened concrete carbonation depth, Title: CPC 18 Measurement of hardened concrete carbonation depth, RILEM CPC () Measurement of Hardened Concrete Carbonation Depth. has been cited by the following article: TITLE: Anticorrosive Effect of. RILEM CPC, “Measurement of Hardened Concrete Carbonation Depth,” . has been cited by the following article: TITLE: Carbonation Resistance and.
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Corrosion of Steel in Concrete: Carbonation depths had reached prestressing steel levels in some locations.
It is clear that further research is required to investigate the localised effects of aggregate and cementitious material on the progression of the carbonation front. The compressive strength results were hradened the nominal values, particularly for 0. The results of the present study show that the placement, orientation and geometry of a concrete element can influence carbonahion the preferential development of the carbonation front on a local scale.
Carbonation of reinforced concrete: The northern facing webs from Beams A and C and the southern facing web of Beam B exhibited greater carbonation than the respective opposing web faces. It appears that only Castro et al. Secondly, it is well documented in the literature that the carbonation front in real-life concrete structures can be quite irregular and can occasionally exhibit maxima that extend far mesurement the average profile.
To receive news and publication updates for Advances in Materials Science and Engineering, enter your email address in the box below. However, some aggregates have absorption levels above these values. Land Transport New Zealand; The opinions and findings of this investigation are those of the measureemnt and are not necessarily those of the supporting organizations. Cement and Hagdened Association UK ; However, the carbonation profile at other locations e.
Eight measurements were taken in the more suitable half cylinder as the cuts were irregular. Better understanding of these effects and their subsequent influences will require further research, preferentially on actual structures and taking account of geometry, orientation and environmental conditions. In places with tropical climate, atmospheric conditions may encourage the CO 2 aggressiveness [ hardwned ].
Scaled photographs of each concrete surface were taken prior to and meazurement the application of the indicator. The RILEM CPC recommendation is commonly referenced for carbonation measurement, however this is designed predominantly for laboratory specimens. Table of Contents Alerts. Her areas of interest include asset management, bridge inspection techniques, and the influence of corrosion on reinforced and prestressed concrete structures.
These zones were not connected to the concrete surface, but were found adjacent to the ducts containing corroding prestressing steel.
This reaction is summarised in Equation 1.
For measuremet current study, the majority of locations with longitudinal cracking coincided with deeper carbonation, especially for the lower duct in Beam C Figure However the majority of these cracks were associated with spalling or adjacent to corroding prestressing cwrbonation, therefore evidence of carbonation should be apparent. High porosity values were obtained for concrete specimens beyond the expected limits for durable concrete. If the number of test sites is limited, then only a small percentage of the entire concrete surface is represented and thus the carbonation levels may be significantly under or over estimated, or be undiagnosed.
Table 3 shows the results from the compressive strength, porosity tests, and fresh concrete slump. Additional resources pertinent to carbonation field investigations were also available . In relation to the cross-section, greater carbonation was more likely towards the upper parts of the beam cross- section and at junctions. Table 4 shows the results from the carbonation depth measurements. Depth profiles of carbonates formed during natural carbonation. His research interests include structural reliability and marine corrosion.
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Beam C was in poor condition with longitudinal cracking of maximum width 20mm wide following the parabolic trajectory of cincrete post-tensioning ducts in Bays 4 and 5, typical of strand corrosion in well bonded, grouted tendons.
Introduction Concrete is the most used material for infrastructure development. Usually, carbonation is modeled as where is the time of exposure, is the carbonation depth at timeand is the carbonation coefficient. Where carbonation depths had reached prestressing levels, the grout mostly exhibited a strong colour change indicative of its highly alkalinity and thus ability to still provide corrosion protection to the steel Figure This neutralization of the pore solution is also called concrete carbonation.
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The atmospheric carbonation coefficients are also presented in Table 5. For the present study, the carbonation profile mostly follows the incidence of aggregate. Whilst carbonation depth measurements are commonplace in most field inspections, it is evident from the present project that only limited information can realistically be obtained, and that the level of carbonation can be underestimated.
Investigations on the carbonation of concrete. This is due in part to the production of calcium carbonate, or calcite as it is more commonly known.
The carbonation results are summarised in Table 2. The measurement of carbonation through chloride drill holes usually is not recommended due to the dust residue of deeper concrete, falsely implying the pH is higher than it may actually be. Enter the email address you signed up with and we’ll email you a reset link. Help Center Find new research papers in: Each web face, top and base flange surfaces were then calculated and recorded.
Concrete is the most used material for infrastructure development.
Investigating the correlation between pre- and post-demolition assessments for precast, post-tensioned beams in service for 45 years. Minimal carbonation was evident along the top flange and bitumen interface.