An observation-based model for corrosion of concrete sewers under aggressive conditions

Wells, T.; Melchers, Robert E.

doi:10.1016/j.cemconres.2014.03.013

Cited by 104 publications

(56 citation statements)

References 28 publications

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“…İkinci adımda, alçı kalsiyum alüminat ile daha da reaksiyona girerek, alçıtaşından daha yüksek hacimde etrenjit (Ca 6 Al 2 (SO 4 ) 3 (OH) 12 ·26H 2 O) oluşmasına ve dolayısıyla daha fazla mikro ve makro kırılmaya neden olabilir. Ciddi asidik koşullar altında, hidratlı çimentolu matris, kalsiyum silikat hidratlarının (C-S-H) kireçsizleşme (dekalsifikasyon) işlemi ile ayrıştırarak, betonun parçalanmasına ve güç kaybına neden olur (Cizer ve ark., 2011;Wells and Melchers 2014). Portland çimento macununun aksine kalsiyum silikat hidrat (C-S-H) hidratasyon ürününün ana bileşenidir, jeopolimerler amorf alümino-silikat matristen yapılmıştır.…”

Section: Introductionunclassified

Jeopolimer Betonun Hayvan Barınaklarında Kullanılabilme Potansiyelinin Araştırılması

Memiş

Kaplan

Yıldızel

2017

Turkish JAF Sci.Tech.

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Önemli miktarda enerji ve ham madde tüketimine neden olan portland çimentosu CO2 emisyonunun yaklaşık %7'sinden sorumludur. Çimento üretiminden kaynaklı CO2 salınımı azaltılmasında farklı yöntemlerin araştırılması ya da CO2 salınımı daha az olan bir bağlayıcı kullanılarak çimentoya alternatif malzeme kullanılmasını zorunlu kılmaktadır. Jeopolimer malzeme ise, beton üretiminde kullanılan portland çimentosunun (PÇ) aksine CO2 salınımı oldukça az, tuzlara ve asitlere dayanımı yüksek, sıcaklık ve ateşe dayanımı yüksek olması gibi birçok farklı özelliği sayesinde çimentoya alternatif malzeme olarak kullanım potansiyeli olan ve araştırılan bir malzemedir. Çalışma kapsamında hayvan barınaklarında jeopolimer betonun etkileri araştırılması amacıyla jeopolimer malzemenin alkali aktivatörü olarak yüksek fırın cürufunun (YFC) %20'si oranında seramik tozu (ST), sodyum silikat (Na2SiO4) ile sodyum hidrosit (NaOH) %60 -40 oranında aktivasyon çözeltisi ile kalsit agregası kullanılarak numuneler hazırlanmıştır. Boyutları 4×4×16 cm numunelerde eğilme ve basınç dayanımları ile 25×25×285 mm numuneler üzerinde de büzülme oranları belirlenmiştir. Jeopolimer betonların hayvan barınaklarındaki durumlarının belirlenmesi amacıyla numuneler %10'luk sülfirik asit (H2SO4) ve sülfat (SO4) solüsyonunda bekletilmiş ve numuneler 28, 56 ve 90. günlerdeki dayanımları karşılaştırılmıştır. Jeopolimer betonun hayvan barınaklarında kullanılmasının avantajlar sağlayabileceği görülmüştür. Investigation of Usability Potential Geopolimer Concrete at Animal Barns Abstract A R T I C L E I N F O A B S T R A C T Research ArticleReceived 08 August 2017 Accepted 10 October 2017Portland cement, which causes significant energy and raw material consumption, is responsible for about 7% of CO2 emissions. In order to reduce CO2 emissions from cement production, with the aim of using a binder with a lower CO2 release or investigation of different methods, alternative materials to cement are required. In contrast to portland cement (PO), which is used in concrete production; geopolimer is a material that is potentially useful as an alternative to cement and is still being explored provides a very low CO2 emission, a high resistance to salts and acids, and a high temperature and fire resistance. In this study, the effects of geopolymer concrete were investigated in animal barn. For this purpose, samples were prepared using calcite aggregate, alkali activator and activation solution. As alkali activator of geopolymer material ceramic sludge (ST) is used at 20% of blast furnace slag (YFC). Sodium silicate (Na2SiO4) and sodium hydroside (NaOH) were used as the activation solution in 60-40% mixing ratio. Bending and compressive strengths were determined in 4×4×16 cm specimens and shrinkage ratios were determined on 25×25×285 mm specimens. In order to determine the conditions of the animal shelters of the geopolymer concrete, the strengths of the samples in 10% sulfuric acid (H2SO4) and sulphate (SO4) solution were compared with 28 th , 56 th and 90 th days. It has been se...

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Section: Introductionunclassified

Jeopolimer Betonun Hayvan Barınaklarında Kullanılabilme Potansiyelinin Araştırılması

Memiş

Kaplan

Yıldızel

2017

Turkish JAF Sci.Tech.

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“…That is, hydration products (i.e., portlandite, calcium aluminate hydrate, ettringite and calcium silica hydrate) dissolve sequentially when the pH of the solution gradually decreases from 12.5 to 8.8 or below [11]. In addition, the MIC is an active deterioration process in which bacteria provide sustained sulfuric acid in the reaction [10]; as a result, the MIC rate can be as high as 12 mm/year in many sewer systems [12] and even 14 mm/year in laboratory setups [13]. The following section provides more detail regarding the MIC process.…”

Section: Fundamentals For Microbially Induced Corrosion Of Sewer Concmentioning

confidence: 99%

“…In these tests, specific conditions such as temperature, nutrients and humidity can be controlled. Furthermore, some researchers [12] mounted the concrete coupons in a real sewer tunnel to observe the physicochemical process of MIC. However, the duration is even longer for these tests incorporating the microbial process than the immersing method, normally in the magnitude of years.…”

Section: Cement-based Rehabilitation-materials Selection Based On the mentioning

confidence: 99%

The Sustainability of Concrete in Sewer Tunnel—A Narrative Review of Acid Corrosion in the City of Edmonton, Canada

Hu²,

Liu

2018

Sustainability

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This paper is intended to conduct a narrative review on the acid corrosion of sewer tunnel concrete in the City of Edmonton-an investigation on the MIC (microbially induced corrosion) mechanism and the potential control methods to improve the sustainability of concrete. Firstly, three categories of main influencing factors were identified for the rate of MIC: hydraulic parameters, environmental factors, and concrete mixture design. Secondly, it is found that the sewer tunnel design plays an essential role in the control of the MIC. Building on that, a review was conducted on eight municipal drainage design standards in consideration of the MIC, indicating a lack of design standards of the flow velocity and pipe material. Finally, an investigation was done for cement-based rehabilitating techniques and materials.

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“…The duration of this stage varies from a few months to years, which is largely dependent on the concentration of CO 2 and H 2 S and other environmental factors in sewers, such as relative humidity and temperature (Jiang et al, 2015;Monteny et al, 2000;Wells and Melchers 2014).…”

Section: The Progression Of Sewer Concrete Corrosionmentioning

confidence: 99%

“…It is largely unkown relating to the sulfide oxidizing pathways within the corrosion layer. Some studies investigated sulfide oxidation of suspended solution of corrosion product previously exposed to H 2 S levels up to 1000 ppm v which is much higher than those in real sewers Jensen et al, 2009;Wells and Melchers 2014). Due to that the gaseous H 2 S concentrations could affect the dominant microbial communities in corrosion layer and hence the sulfide oxidizing activity, it is unkown whether the results from those studies could represent those in real sewers.…”

Section: Introductionmentioning

confidence: 99%

Improving the understanding of concrete sewer corrosion through investigations of the gaseous hydrogen sulfide uptake and transformation processes in the corrosion layer

Sun¹

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Sulfide-induced corrosion of sewer infrastructure costs multi-billion dollars globally. Sewer maintenance and management largely depends on the estimation of the sewer corrosion rate, which currently can be very rough due to poor understanding of details of the process. Hence improved understanding of the corrosion processes has a major beneficial impact globally through increased service life and reduced repair/replacement costs. The overall aim of this thesis is to improve the understanding of sewer corrosion processes and develop strategies for corrosion control.To rapidly and non-destructively monitor the corrosion process, a methodology was developed based on measuring the H 2 S (sulfide) uptake rates (SUR) of concrete. The SUR of concrete coupons was determined by monitoring the temporal gaseous H 2 S concentrations in a temperature-and humidity-controlled gas-tight reactor. The results from repeated tests showed good reliability of the method. A severely corroded coupon exhibited higher SUR than a less corroded coupon, suggesting that the former having a higher sulfide oxidation activity than the latter. Additionally, temperature changes had a stronger effect on the SUR of the heavily corroded coupon compared to the less corroded coupon. The corrosion rates estimated from the SUR agreed well with those observed in real sewers under similar conditions. The effect high H 2 S concentrations on the SUR of coupon were investigated. During the high load situation, the SUR increased significantly but then decreased (compared to the baseline SUR) by about 7 -14% and 41 -50% immediately after short-and long-term high H 2 S load periods, respectively. For both conditions, the SUR gradually (over several hours) recovered to approximately 90% of the baseline SUR. Further tests suggest multiple factors may contribute to the observed decrease of SUR directly after the high H 2 S load. This includes the temporary storage of elemental sulfur in the corrosion layer and inhibition of sulfide oxidizing bacteria due to high H 2 S level and temporary acid surge. The sensitivity of the coupon SUR towards high H 2 S loads was largely dependent on its historical H 2 S exposure levels. IIThe deprivation of gaseous H 2 S for 1 h consistently caused temporary increase of the H 2 S uptake rate (SUR) immediately upon H 2 S re-supply whereas deprivation of both gaseous H 2 S and O 2 for 1 h posed little increase of the SUR after re-supply. The results suggest that the H 2 S uptake process could be limited by the oxidation of reduced sulfur species. Furthermore, the SUR decreased by 1.2% after deprivation of H 2 S for a relative long-term (i.e. 12 h), suggesting a reduced biological activity after the extended "starvation".The details of sulfide oxidation by comparing oxidation activity of a suspended solution of a corrosion layer with gaseous H 2 S uptake activity of a coupon were investigated. With sufficient dissolved oxygen (DO) and in the presence of sulfide, the mole ratio of consumed The potential of mitigating sewer cor...

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An observation-based model for corrosion of concrete sewers under aggressive conditions

Cited by 104 publications

References 28 publications

Jeopolimer Betonun Hayvan Barınaklarında Kullanılabilme Potansiyelinin Araştırılması

Jeopolimer Betonun Hayvan Barınaklarında Kullanılabilme Potansiyelinin Araştırılması

The Sustainability of Concrete in Sewer Tunnel—A Narrative Review of Acid Corrosion in the City of Edmonton, Canada

Improving the understanding of concrete sewer corrosion through investigations of the gaseous hydrogen sulfide uptake and transformation processes in the corrosion layer

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