Effectiveness of admixtures, surface treatments and antimicrobial compounds against biogenic sulfuric acid corrosion of concrete

2009 ◽  
Vol 31 (3) ◽  
pp. 163-170 ◽  
Author(s):  
Willem De Muynck ◽  
Nele De Belie ◽  
Willy Verstraete
Materials ◽  
2021 ◽  
Vol 14 (23) ◽  
pp. 7109
Author(s):  
Wei Yang ◽  
Pinghua Zhu ◽  
Hui Liu ◽  
Xinjie Wang ◽  
Wei Ge ◽  
...  

Geopolymer binder is expected to be an optimum alternative to Portland cement due to its excellent engineering properties of high strength, acid corrosion resistance, low permeability, good chemical resistance, and excellent fire resistance. To study the sulfuric acid corrosion resistance of geopolymer concrete (GPC) with different binding materials and concentrations of sodium hydroxide solution (NaOH), metakaolin, high-calcium fly ash, and low-calcium fly ash were chosen as binding materials of GPC for the geopolymerization process. A mixture of sodium silicate solution (Na2SiO3) and NaOH solution with different concentrations (8 M and 12 M) was selected as the alkaline activator with a ratio (Na2SiO3/NaOH) of 1.5. GPC specimens were immersed in the sulfuric acid solution with the pH value of 1 for 6 days and then naturally dried for 1 day until 98 days. The macroscopic properties of GPC were characterized by visual appearance, compressive strength, mass loss, and neutralization depth. The materials were characterized by SEM, XRD, and FTIR. The results indicated that at the immersion time of 28 d, the compressive strength of two types of fly ash-based GPC increased to some extent due to the presence of gypsum, but this phenomenon was not observed in metakaolin-based GPC. After 98 d of immersion, the residual strength of fly ash based GPC was still higher, which reached more than 25 MPa, while the metakaolin-based GPC failed. Furthermore, due to the rigid 3D networks of aluminosilicate in fly ash-based GPC, the mass of all GPC decreased slightly during the immersion period, and then tended to be stable in the later period. On the contrary, in metakaolin-based GPC, the incomplete geopolymerization led to the compressive strength being too low to meet the application of practical engineering. In addition, the compressive strength of GPC activated by 12 M NaOH was higher than the GPC activated by 8 M NaOH, which is owing to the formation of gel depended on the concentration of alkali OH ion, low NaOH concentration weakened chemical reaction, and reduced compressive strength. Additionally, according to the testing results of neutralization depth, the neutralization depth of high-calcium fly ash-based GPC activated by 12 M NaOH suffered acid attack for 98 d was only 6.9 mm, which is the minimum value. Therefore, the best performance was observed in GPC prepared with high-calcium fly ash and 12 M NaOH solution, which is attributed to gypsum crystals that block the pores of the specimen and improve the microstructure of GPC, inhibiting further corrosion of sulfuric acid.


2018 ◽  
Vol 158 ◽  
pp. 33-41 ◽  
Author(s):  
Yu Yang ◽  
Tao Ji ◽  
Xujian Lin ◽  
Caiyi Chen ◽  
Zhengxian Yang

2018 ◽  
Vol 878 ◽  
pp. 23-27 ◽  
Author(s):  
Ming Qiang Lin ◽  
Feng Juan Dai ◽  
Jia Tao Li

The corrosion of concrete structures is serious in sulfuric acid environments. Corrosion damage of reinforcements caused sulfuric acid corrosion is very serious. The rapid experiments of sulfuric acid corrosion steel bars were carried out, and the apparent morphology and mechanical properties of sulfuric acid corrosion steel bars were studied. The results show that the corrosion of steel bars is uniform corrosion. With the increase of corrosion rate, the yield platforms and the yield strengths and ultimate strengths are reduced. Based on the experimental datas, the relationship models between yield strengths and ultimate strengths and corrosion rates were obtained. The constitutive models of corrosion steel bars were established. The stress - strain relationship model is in good agreement with the experimental data.


2000 ◽  
Vol 30 (4) ◽  
pp. 623-634 ◽  
Author(s):  
J Monteny ◽  
E Vincke ◽  
A Beeldens ◽  
N De Belie ◽  
L Taerwe ◽  
...  

2001 ◽  
Vol 127 (7) ◽  
pp. 580-584 ◽  
Author(s):  
F. Jahani ◽  
J. Devinny ◽  
F. Mansfeld ◽  
I. G. Rosen ◽  
Z. Sun ◽  
...  

2014 ◽  
Vol 659 ◽  
pp. 28-33
Author(s):  
Alexandru Barca ◽  
Bogdan Istrate ◽  
Eduard Sebastian Barca ◽  
Vasile Ionut Crismaru ◽  
Corneliu Munteanu

Gas oil is the fuel used in internal combustion engines with ignition through compression. This fuel contains various amounts of sulfur, an element that can contribute in the process of combustion to the forming of sulfuric acid on the internal walls of the cylinder. Sulfuric acid is a highly corrosive substance which can lead in time to the deterioration of the functional surface of the motor cylinder. For an accurate evaluation of the analyzed coatings a study was carried out on the resistance to sulfuric acid corrosion of the two coatings of Al2O330(Ni20Al) and NiAlSi. To this purpose a solution of sulfuric acid with a 30% concentration was used. The samples were immersed in sulfuric acid for 70 hours.


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