Role of Potassium Acetate Deicer in Accelerating Alkali–Silica Reaction in Concrete Pavements

2011 ◽  
Vol 2240 (1) ◽  
pp. 70-79 ◽  
Author(s):  
Chandni Balachandran ◽  
Jan Olek ◽  
P. R. Rangaraju ◽  
Sidney Diamond
Keyword(s):  
Potassium Acetate ◽  
Alkali Silica Reaction ◽  
Concrete Pavements ◽  
Potassium Acetate Deicer

The Role of Alkalis in Hydraulic Mixtures

2019 ◽  
Vol 955 ◽  
pp. 62-67
Author(s):  
Lukáš Procházka ◽  
Jana Boháčová
Keyword(s):  
Mechanical Properties ◽  
Blast Furnace ◽  
Blast Furnace Slag ◽  
Alkali Silica Reaction ◽  
Type Ii ◽  
Hydration Products ◽  
Experimental Part ◽  
Ph Values ◽  
Furnace Slag

Alkali substances are present in cements used as a binder in concrete only in a minimum content. The most known process that alkali causes is the alkali-silica reaction. In this reaction, the alkali contained in the cement or supplied from the outside with an inappropriately selected aggregate containing amorphous SiO2. This reaction results in the development of hydration products, resulting in an increase in the volume of the original components, which can cause a breakage of the concrete structure and subsequent disintegration. The range of alkali-silica reaction can be reduced by the use of a suitable aggregate or the use of Type II admixtures which are characterized by pozzolanic or latently hydraulic activity. These admixtures react with alkali and then no longer react with the amorphous SiO2 contained in the aggregate. Alkalis also affect other properties of concrete such as basic physical-mechanical properties, frost resistance and pH.In the experimental part the pH values were compared between mixtures of Portland cement and alkaline activated blast furnace slag using slag aggregate from the heap Koněv.

The Role of Water in the Intercalation of Kaolinite with Potassium Acetate

1998 ◽  
Vol 204 (2) ◽  
pp. 227-236 ◽  
Author(s):  
Ray L. Frost ◽  
Janos Kristof ◽  
Gina N. Paroz ◽  
Thu Ha Tran ◽  
J.Theo Kloprogge
Keyword(s):  
Potassium Acetate

scholarly journals Role of Aluminum and Lithium in Mitigating Alkali-Silica Reaction—A Review

2022 ◽  
Vol 8 ◽  
Author(s):  
Zhenguo Shi ◽  
Barbara Lothenbach
Keyword(s):  
Cementitious Materials ◽  
Supplementary Cementitious Materials ◽  
Lithium Salts ◽  
Alkali Silica Reaction ◽  
Reaction Products ◽  
Ambient Conditions ◽  
Slow Kinetics ◽  
Zeolite Formation ◽  
Available Information

Effective mitigation of alkali-silica reaction (ASR) is critical for producing durable concrete. The use of alumina-rich supplementary cementitious materials (SCMs) and chemical admixtures such as lithium salts to prevent expansion caused by ASR was first reported 70 years ago, shortly after the discovery of ASR in 1940s. Despite numerous investigations, the understanding of the mechanisms of Al and Li for mitigating ASR remain partially inexplicit in the case of Al, and hardly understood in the case of Li. This paper reviews the available information on the effect of Al and Li on ASR expansion, the influencing factors, possible mechanisms and limitations. The role of Al in mitigating ASR is likely related to the reduction of dissolution rate of reactive silica. Moreover, the presence of Al may alter the structure of crystalline ASR products to zeolite or its precursor, but such effect seems to be not that significant at ambient conditions due to the slow kinetics of zeolite formation. Several mechanisms for the lithium salts in mitigating ASR have been proposed, but most of them are not conclusive primarily due to the lack of knowledge about the formed reaction products. Combination of Al-rich SCMs and lithium salts may be used as an economic solution for ASR mitigation, although systematic studies are necessary prior to the applications.

Alkali-Silica Reaction in Concrete Pavements

2016 ◽  
Vol 711 ◽  
pp. 714-721
Author(s):  
Katja Voland ◽  
Frank Weise ◽  
Birgit Meng
Keyword(s):  
Performance Test ◽  
Preventive Measures ◽  
Test Methods ◽  
Alkali Silica Reaction ◽  
Concrete Pavements ◽  
Research Projects ◽  
Concrete Composition ◽  
Traffic Loading ◽  
Federal Institute ◽  
Materials Research

A significant number of German concrete motorway pavements have shown damage only a few years after construction. The alkali-silica-reaction (ASR) is often one of the reasons for this damage. German guidelines and regulations focus on the optimisation of the concrete composition to avoid damage due to ASR. Moreover, diverse research projects have dealt with the development and optimisation of ASR performance test methods with and without external alkali supply. However, the influence of other parameters on the occurrence and intensity of a damaging ASR had not yet been taken into account. Such parameters include, e.g., insufficient curing and the modifications of concrete’s porosity due to the use of slip form pavers. Likewise, the increased traf-fic loading had not yet been considered. The Federal Institute for Materials Research and Testing (BAM) assesses these parameters and processes in a number of projects. These projects aim primarily to increase the durability of the concrete pavements, in particular by improving preventive measures that may be taken before or after the construction of concrete pavements. This paper gives a short overview of BAM’s projects concerning ASR in concrete pavements. Furthermore, results regarding the influence of the cyclic traffic loading on ASR are presented.

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