Acid attack on hydrated cement — Effect of mineral acids on the degradation process

Gutberlet, T.; Hilbig, H.; Beddoe, R.E.

doi:10.1016/j.cemconres.2015.03.011

Cited by 157 publications

(67 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…There are also fewer cracks present when compared with PCp. The microstructure and integrity of the degraded layer is important for acid resistance because it determines the ability of this layer to remain a protective barrier during further attack [61]. The degraded layers on the GP samples appear much more likely to resist further attack due to the presence of fewer cracks and voids.…”

Section: Mass Lossmentioning

confidence: 99%

Resistance of geopolymer and Portland cement based systems to silage effluent attack

Aiken

Sha

Kwasny

et al. 2017

Cement and Concrete Research

109

View full text Add to dashboard Cite

Abstract:Traditional Portland cement (PC) concrete has been used for many years in the agricultural industry for the construction of silos and silage effluent storage facilities. However, the acidic nature of the silage effluent produced by silage has led to severe degradation of PC concrete which in turn has significant environmental and financial implications. This study compares the resistance of PC and geopolymer (GP) mortars and pastes to silage effluent over 12 months. The GP samples displayed increased resistance to silage effluent in terms of mass and strength loss. Analysis of microstructure suggests that the increased stability of the reaction products is the main factor behind increased silage effluent resistance when compared with PC. It was also found that pulverised fuel ash (PFA) and ground granulated blast furnace slag (GGBS) blends with a higher PFA content may offer increased long term silage effluent resistance due to the nature of the main binder gel produced in PFA dominant systems.

show abstract

Section: Mass Lossmentioning

confidence: 99%

Resistance of geopolymer and Portland cement based systems to silage effluent attack

Aiken

Sha

Kwasny

et al. 2017

Cement and Concrete Research

109

View full text Add to dashboard Cite

show abstract

“…Portland cement is used for constructing the 154-kV-porcelain insulators. Previous works it has been investigated that the pores in the cement vary in size from a few µm to mm, and they can be classified, as shown in Figure 3 It has also been reported that it exists in various sizes, ranging from the size that can be measured and observed with SEM to the size that can be visible to the naked eye as shown in Figure 4 [17]. The smallest pores can cause a capillary phenomenon.…”

Section: Resultsmentioning

confidence: 99%

“…However, as the porcelain insulator is a composite material of metal, cement, and ceramic, it is not easy to measure the cracks because of X-ray scattering. Thus, it has been advised to perform 3D-CT with a very high output power for the analysis [17]. Efforts are taken to produce as little pores as possible using air-entraining water-reducing agents.…”

Section: Resultsmentioning

confidence: 99%

“…There is also the possibility of radial cracking of porcelain from cement expansion. When rough surfaces are caused, due to the deterioration of porcelain insulator, the generated charges are concentrated in the cement resulting in the possibility of corona discharging [17,18]. Pores are generated in the cement of the cap, due to the concentration of the electric field.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Analysis of Cement Deterioration in Outdoor High-Voltage Insulator

et al. 2019

View full text Add to dashboard Cite

Suspension type porcelain insulators used in overhead transmission lines comprise metal, ceramic, and cement. The deterioration of cement can lead to mechanical separation. For the degradation analysis, varied sizes of pores ranging from a few µm (capillary pores) to tens to hundreds of mm (detectable by naked eyes) were considered. Cracks that were hard to view with naked eyes were identified by staining with a fuchsine solution. The hydrogen ion concentration and pH value indicate the extent to which the cement is deteriorated. The longer the cement is used, the lower its pH value. High mechanical strength is considered an important advantage of porcelain insulators, and it may decline, if the cement is used for a longer period of time. Water ingress may also occur, resulting in expansion, due to the rehydration of the cement. The process and mechanism of expansion of cement, due to infiltration of water were described. As a method of analysis, a universal indicator was employed to evaluate the pH changes in cement. It was observed that the pH value was 12-13 for new products. However, for products that were used for 52 years, the pH value was under 7, which indicated an acidic tendency, due to deterioration.

show abstract

“…This leads to a very low pH (<1) hot-acid attack on the cement sheath (Alexander et al, 2013;Lichti and Yanagisawa, 2015;Villasenor and Vicedo, 2010). The degradation of Portland cement by acid proceeds through decalcification of portlandite followed by calcium loss from calcium-silicate hydrate phases at a pH below about 12·4, causing an increase in porosity and decrease in mechanical strength (Beddoe and Dorner, 2005;Glasser et al, 2008;Gutberlet et al, 2015;Kudowski, 2004;Puertas et al, 2012;Zivica, 2004). The acid diffusivity through the calcium-depleted hydrates is of an order of magnitude higher than that through the original material (Bentz and Garboczi, 1992).…”

Section: Introductionmentioning

confidence: 99%

Acid resistance of calcium aluminate cement–fly ash F blends

Pyatina

Sugama

2016

Advances in Cement Research

View full text Add to dashboard Cite

The short-term resistance to sulfuric acid at 90°C of four calcium aluminate cement (CAC)-fly ash class F (FAF) blends activated with sodium metasilicate (thermal shock resistant cements (TSRCs)), cured at 300°C, was compared to that of a calcium phosphate cement (CPC) (CAC-FAF blend activated with sodium hexametaphosphate) and a Portland cement class G/silica blend. The mechanical properties and compositions of the acid-exposed samples were evaluated by measuring their compressive strength and by means of x-ray diffraction, μEDX (energy-dispersive x-ray spectrometry), thermogravimetric and Fourier transform infrared analyses. All calcium-containing hydrates were sensitive to the conditions of acid exposure. In the TSRC blends, these hydrates included hydrogrossular, feldspar family minerals and zeolites; in CPC, feldspar minerals and phosphate phases; and in the class G/silica blend, portlandite and tobermorite.Crystalline calcium sulfates formed in the acid-exposed surfaces with the exception of the most aluminium-rich TSRC samples where only potassium(sodium) aluminium sulfate, alunite, was detected. This sample underwent the least changes in weight, compressive strength and had the lowest sulfur permeation into the sample core. Calcium sulfates precipitated on sample surfaces limited sulfur penetration into the core of calcium-rich TSRC, CPC and G/silica blends.

show abstract

Acid attack on hydrated cement — Effect of mineral acids on the degradation process

Cited by 157 publications

References 22 publications

Resistance of geopolymer and Portland cement based systems to silage effluent attack

Resistance of geopolymer and Portland cement based systems to silage effluent attack

Analysis of Cement Deterioration in Outdoor High-Voltage Insulator

Acid resistance of calcium aluminate cement–fly ash F blends

Contact Info

Product

Resources

About