Preludium 21

DESCRIPTION:

The subject of the research is focused on alkali-silica reaction (ASR) products which consist of sodium and potassium silicates in the form of gel and its properties under the influence of deicing agents.

The objective of the research is the effect of deicing agents solution on microstructure and mechanical properties of ASR gel to determine possible correlation with the expansion and damage in cement based materials. Particular attention will be paid to effect of the external source of alkalis (NaCl, HCOOK, HCOONa) and additional internal source (alkali leaching from mineral aggregate) on the chemical composition of ASR product. It is supposed that exposure of specimens to the various deicers concentrations will influence the chemical composition of ASR gel, which will affect its mechanical properties.

The research is financially supported by Polish National Science Centre (PRELUDIUM 2021/41/N/ST8/03799).

PROJECT STATUS: Completed

START DATE: 21 January 2022

END DATE: 20 March 2024

TOPICS: Alkali-Silica Reaction, Cement Matrix Composites, Alkali-Silica Gel, Mechanical Properties, Sodium Chloride, Deicing Agents, Nanoindentation, Materials Characterization

The alkali-silica reaction (ASR) is one of the main causes of deterioration in concrete surfaces. It occurs between reactive minerals in aggregates and sodium and potassium hydroxides, commonly present in the pore solution of concrete. As a result of silica dissolution in the presence of a highly alkaline pore solution, expansive ASR reaction products are formed. This leads to cracking of aggregate grains and cement matrix, significantly reducing the durability of concrete. Due to the climatic conditions in Poland during the winter season, deicing agents such as sodium chloride (NaCl), potassium formate (HCOOK), and sodium formate (HCOONa) are used on road and airport pavements. These agents may serve as additional sources of alkalis and contribute to increased ASR intensity, thus reducing the durability of concrete surfaces.

The aim of the Project was to analyze the influence of deicing agent solutions on the chemical composition, microstructure, and mechanical properties of alkali-silica reaction products formed in concrete. Among the conducted research and obtained results, the following achievements deserve attention:

• It has been demonstrated that deicing agents increase the risk of damage to concrete pavements by intensifying ASR.
• It has been shown that the alkali leaching process during testing significantly influences the assessment of the degree of damage to these samples, and the degree of damage to concrete samples is directly related to the alkali leaching process during testing.
• Alkali leaching from granite aggregates was investigated, and their influence on the alkali content in the concrete pore solution was determined, especially concerning the presence of deicing agents.
• The quantitative content of reactive minerals in granite aggregates was determined, and its effect on the destruction of concrete structures was examined.
• The influence of deicing agents on the chemical composition of the pore solution was determined, and the relationship between alkali content in the solution and sample expansion was established.
• Raman spectroscopy was used for a detailed analysis of the structure of ASR products formed using deicing agents.
• Mechanical properties of ASR products were characterized on a micro and nano scale: hardness and modulus of elasticity were determined, and correlations between them and chemical composition were established; higher values of hardness and modulus of elasticity were correlated with higher potassium ion content from deicing agents.
• Innovative tests on the compressive strength of ASR products were carried out on a global scale.

The research conducted as part of the project fills a significant gap in the field of building materials, particularly in the context of civil and materials engineering, regarding the properties of alkali-silica reaction products in the presence of deicing agents. For the first time, comprehensive studies of the mechanical properties of ASR products were conducted, considering different deicing agents, which constitutes a significant step towards understanding the mechanism of this reaction and ways to minimize its negative impact on concrete structures. Understanding the influence of deicing agents on the chemical composition of the pore solution in cement composites and their correlation with expansion allows for more effective use of these substances, minimizing the risk of ASR damage while ensuring appropriate properties and durability of concrete pavements.

The results obtained in the Project can serve as a starting point for further research on preventing ASR to develop better strategies for preventing concrete damage caused by this phenomenon. This knowledge will help better understand which preventive methods can be effective, especially when deicing agents are used. Analyzing the relationship between chemical composition and ASR product properties and the amount of alkalis in the pore solution is crucial for identifying factors influencing ASR development, enabling better monitoring and control of processes leading to damage in cement composites. The results of these studies can also serve as a basis for modeling the durability of structures exposed to the action of deicing agents, ultimately contributing to the development of more effective strategies for preventing and repairing ASR damage, which is essential for the durability and safety of building structures.

A. Antolik, D.  Jóźwiak-Niedźwiedzka, ASR induced by chloride- and formate-based deicers in concrete with non-reactive aggregates, Construction and Building Materials, 400, 2023, 132811, 1-13, https://doi.org/10.1016/j.conbuildmat.2023.132811

A. Antolik, M. Dąbrowski, D. Jóźwiak-Niedźwiedzka, Petrographic Evaluation of Aggregate from Igneous Rocks: Alkali–Silica Reaction Potential, Minerals, 13(8), 2023, 1004, https://doi.org/10.3390/min13081004

D. Jóźwiak-Niedźwiedzka, R. Jaskulski, K. Dziedzic, A. Antolik, M. Dąbrowski, Influence of Calcination Temperature and Amount of Low-Grade Clay Replacement on Mitigation of the Alkali–Silica Reaction, Materials, 16(8), 2023, 3210, https://doi.org/10.3390/ma16083210

D. Jóźwiak-Niedźwiedzka, R. Jaskulski, K. Dziedzic, A. Antolik, D.M. Jarząbek, Initial Characteristics of Alkali–Silica Reaction Products in Mortar Containing Low-Purity Calcined Clay, Materials, 17(10), 2024, 2207, https://doi.org/10.3390/ma17102207

A. Antolik, Influence of sodium and potassium formate on the ASR reactivity of granite aggreagate, Structure and Environment, , 14(3), 008, 2022, 69-75, https://doi.org/10.30540/sae-2022-008

A. Antolik, D. Jóźwiak-Niedźwiedzka, K. Dziedzic, P. Lisowski, Effect of Potassium Formate on Alkali–Silica Reaction in Aggregates with Different Categories of Reactivity, Materials Proceedings 2023, 13(1), 13, https://doi.org/10.3390/materproc2023013013

D. Jóźwiak-Niedźwiedzka, A. Antolik, Assessment of highway pavement concrete suffering from alkali-silica reaction: case study, Materiales de Construcción,  72(348), 2022, 1-9, http://doi.org/10.3989/mc.2022.296922

D, Jóźwiak-Niedźwiedzka, A. Antolik, K. Dziedzic, P. Lisowski, Potential alkaline reactivity of sands from domestic deposits, Roads and Bridges - Drogi i Mosty, 21(3), 2022, 253-271, http://doi.org/10.7409/rabdim.022.015