Thermodynamic simulation of sulfate attack in cement mortars

Q: How can I download an article?

To download an article from SID, first log in to the site, search for the article title, and click on the 'Download Article' option.

Q: How can I download an ISI article?

To download an ISI article on SID, enter the keyword or article title in the search bar, view the relevant results, click on the desired article, and select the 'Download Article' option.

Q: How can I access the SID database?

To access the SID database, visit SID.ir, create an account, and log in to access scientific resources.

Q: Is downloading articles from SID free?

Some articles on SID are available for free, while others require payment. Details are specified on the article's page.

TARIGHAT A.; MODARRES Y.; MOHAMMADI M.

Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Journal Paper

Paper Information

Journal: Modares Civil Engineering journal Year:2018 | Volume:18 | Issue:2 Page(s): 159-168

Download Full-Text

مرکز اطلاعات علمی Scientific Information Database (SID) - Trusted Source for Research and Academic Resources

Persian Verion

View:

406

Download:

Cites:

Information Journal Paper

Title

Thermodynamic simulation of sulfate attack in cement mortars

Author(s)

TARIGHAT A. | MODARRES Y. | MOHAMMADI M. | Issue Writer Certificate

Keywords

Sulfate attackQ1

SimulationQ2

ThermodynamicQ1

Portland cementQ2

Rice husk ashQ1

Abstract

Sulfate attack is a series of physico-chemical reactions between hardened cement paste and sulfate ions. Sulfate ion penetration into the cement results in the formation of voluminous and deleterious phases such as gypsum and ettringite which are believed to cause deterioration and expansion of concrete; However, there is no direct relationship between ettringite or solids formation during the Sulfate attack and the amount of expansion. Concrete deterioration due to Sulfate attack depends on multiple elements, however, in experimental studies, the implementation of the elements and obtaining the results in a short time are very difficult. Therefore, the significance of theoretical and software modelling along with in experimental studies, reducing the time and cost, increases so much as to achieve reliable results. Thermodynamic Simulations, in this research, are employed according to the method of minimizing Gibbs free energy in order to better understand the external Sulfate attack and the behaviour of mortar samples made of ordinary Portland cement and blended cements. GEM software which is able to calculate the stable phase as a function of reactants, temperature and pressure is employed. In this software chemical interactions involving solids, solid solutions, metls, gas/fluid mixture, aqueous electrolyte, (non-) electrostatic surface complexation, and ion exchange can be considered simultaneously in the chemical elemental stoichiometry (+ electrical charge) of the system, i. e. without any mass balance constraints for ligands or surface sites. GEMS simulates various masstransfer processes and reaction paths, such as mixing; But this software cannot replace our knowledge of physical chemistry. It does not apply any restrictions on the calculated hydrate types. This method is based on the theory that states the core samples are never or hardly ever affected by sulfate while the outer layer is in contact with a large amount of sulfate solution. The advantage of this model is that the calculations are very fast but the calculated data are not time dependent. Modelling the Sulfate attack is done by increasing the amount of sulfate in cement. Type and volume of phases formed during the Sulfate attack and factors affecting that such as cement chemistry, Rice husk ash and sulfate solution with different concentrations were studied with the help of this method. Simulation of mortar samples was performed in sodium sulfate with concentrations of 4 and 44 g per liter and 10 and 15 percent Rice husk ash substitution. Mortar samples at 20 ° C and water-cement ratio of 0. 5 is assumed. Rice husk ash substitution has an effective role in microstructures improvement, reduced impermeability, and volume of forming products. Sodium sulfate is more dangerous and destructive compared to other sulfates like calcium sulfate or potassium sulfate and forms phases with higher volumes. The results clearly indicate that Rice husk ash, consumed portlandite completely and produced maximum volume of calcium silicate hydrate(C-S-H) by 15 percent replacement and also there is not a simple relationship between the increase of formed phases by the penetration of sulfate ions and the observed expansion. Generally, the results correspond to the studies and in experimental results which have examined micro structure.

Cites

No record.

References

No record.

Cite

APA: Copy

TARIGHAT, A., MODARRES, Y., & MOHAMMADI, M.. (2018). Thermodynamic simulation of sulfate attack in cement mortars. MODARES CIVIL ENGINEERING JOURNAL, 18(2 ), 159-168. SID. https://sid.ir/paper/256795/en

Vancouver: Copy

TARIGHAT A., MODARRES Y., MOHAMMADI M.. Thermodynamic simulation of sulfate attack in cement mortars. MODARES CIVIL ENGINEERING JOURNAL[Internet]. 2018;18(2 ):159-168. Available from: https://sid.ir/paper/256795/en

IEEE: Copy

A. TARIGHAT, Y. MODARRES, and M. MOHAMMADI, “Thermodynamic simulation of sulfate attack in cement mortars,” MODARES CIVIL ENGINEERING JOURNAL, vol. 18, no. 2 , pp. 159–168, 2018, [Online]. Available: https://sid.ir/paper/256795/en

Related Journal Papers