Talk:Alkali–silica reaction

message: It seems inappropriate to single out the Los Angeles 6th St Viaduct as an example, unless you intend to comprehensively list the many thousands of US structures affected by ASR.  An better alternative would be to provide an anonymous picture of typical ASR attack. . . .LinguisticDemographer 14:13, 11 August 2007 (UTC)
replies: text: Raleigh,NC ripping up 8 lanes, 2 feet thick, 11 miles; after 11 years of service.~  — Preceding unsigned comment added by Wikipietime (talk • contribs) 02:39, 20 March 2013 (UTC)
thread_title: Examples of ASR

message: I think that Alkali Silica Reaction and Alkali-aggregate reaction are essentially the same thing and propose that the latter be merged and changed to a redirect to here.  –Moondyne 01:57, 9 December 2008 (UTC)
thread_title: Merge proposal

message: Since the first publication on ASR by Stanton (1940),  years ago, a so huge amount of papers has been published in the literature that it is a superhuman task to read only a fraction of them and to make a good synthesis of the most relevant. Readers are overwhelmed by the avalanche of information available on the subject and are often drown in the sea of publications. 
How to adequately sort this huge mass of information to only extract the most relevant and appropriate one? How to search literature in the most effectively way? According to the impact factors of journals or popularity ranking index in a Google scolar search? According to the h-index of authors to attempt to assess their citation impact? Or by mainly referring to state-of-the art books and up-to-date review works as advised by Wikipedia policy? An excellent discernment is definitely required to properly cite the main conclusions and outcomes of the best works and to give proper credit to the true discoverers while in particular avoiding works simply repeated every decade without added value. It would be useful to gather and to centrally maintain up to date a limited list of mandatory references and list of essential books and review works while avoiding useless inflation. The aim being, of course, to guide the reader and to provide him with a clear vision to try to better understand a very complex system. Shinkolobwe (talk) 13:48, 28 April 2020 (UTC)
thread_title:  How to tackle this sea of information on ASR? 

message: It would be useful to develop the following aspects: 
===Chemical mechanisms of ASR===
* Mechanism at the level of individual aggregate with didactic figures
* Osmotic effects (S. Chatterji, Danemark)
* Electrical double layer (EDL) (G. Sposito, USA)
* Effect of lithium ions on the ASR mitigation: how does it works? 
** Various hypotheses, mechanisms, processes and theories
* Positive and negative effects of silica fume addition
* Chemical coupling with delayed ettringite formation (DEF), same mitigating effect by lithium ions, blast furnace slag (BFS) or supplementary cementitious materials (SCM), CEM III (OPC-BFS), ...
====Effect of deicing salts on ASR====
Effect of deicing salts (NaCl) on alkali-silica reaction. It is observed that deicing salts increase the sensitivity of silicate minerals to ASR, but the reason is less well known and several mechanisms could play a role:
* Anion exchange in calcium aluminates leading to the formation of Friedel's or Kuzel's salts (chloroaluminate, AFm phases), simplified as: Cl– + AFm–OH → AFm–Cl + OH–
* However, this effect is counteracted by other reactions occurring with AFm, a.o. the following ones: 
** AFt + OH– → AFm (reaction favoring delayed ettringite formation, DEF)
** AFt + Cl– → Friedel's salt + SO42– + OH– 
* Effect of ionic strength (IS) on the solubility of different solid phases in concrete
** Reference: 
* Physical effect due to an increase of the concrete porosity where deicing salts penetrate
* Chatterji hypothesis of ultrafiltration of ions selectively penetrating into the aggregate:  Ca2+ and Cl– remaining out of the aggregates while only Na+ and OH– could only penetrate inside the porous silica network to form the soluble alkali gel (effect of selective membrane played by the gel or the porous structure of amorphous silica).
* Certainly not simply the direct reaction of NaCl or KCl with portlandite (implausible route, closed door): . Indeed, the equilibrium of this reaction is strongly displaced to the left because of the low solubility of portlandite.
* and maybe other totally unsuspected ways, or entrance doors,  still exist to explain the effect of deicing salts on ASR. 
* ...
Shinkolobwe (talk) 18:20, 29 April 2020 (UTC)
thread_title:  Future works and support required 

message: * Mechanism at the level of individual aggregate with didactic figures
* Osmotic effects (S. Chatterji, Danemark)
* Electrical double layer (EDL) (G. Sposito, USA)
* Effect of lithium ions on the ASR mitigation: how does it works? 
** Various hypotheses, mechanisms, processes and theories
* Positive and negative effects of silica fume addition
* Chemical coupling with delayed ettringite formation (DEF), same mitigating effect by lithium ions, blast furnace slag (BFS) or supplementary cementitious materials (SCM), CEM III (OPC-BFS), ...
====Effect of deicing salts on ASR====
Effect of deicing salts (NaCl) on alkali-silica reaction. It is observed that deicing salts increase the sensitivity of silicate minerals to ASR, but the reason is less well known and several mechanisms could play a role:
* Anion exchange in calcium aluminates leading to the formation of Friedel's or Kuzel's salts (chloroaluminate, AFm phases), simplified as: Cl– + AFm–OH → AFm–Cl + OH–
* However, this effect is counteracted by other reactions occurring with AFm, a.o. the following ones: 
** AFt + OH– → AFm (reaction favoring delayed ettringite formation, DEF)
** AFt + Cl– → Friedel's salt + SO42– + OH– 
* Effect of ionic strength (IS) on the solubility of different solid phases in concrete
** Reference: 
* Physical effect due to an increase of the concrete porosity where deicing salts penetrate
* Chatterji hypothesis of ultrafiltration of ions selectively penetrating into the aggregate:  Ca2+ and Cl– remaining out of the aggregates while only Na+ and OH– could only penetrate inside the porous silica network to form the soluble alkali gel (effect of selective membrane played by the gel or the porous structure of amorphous silica).
* Certainly not simply the direct reaction of NaCl or KCl with portlandite (implausible route, closed door): . Indeed, the equilibrium of this reaction is strongly displaced to the left because of the low solubility of portlandite.
* and maybe other totally unsuspected ways, or entrance doors,  still exist to explain the effect of deicing salts on ASR. 
* ...
Shinkolobwe (talk) 18:20, 29 April 2020 (UTC)
thread_title: Chemical mechanisms of ASR

message: Effect of deicing salts (NaCl) on alkali-silica reaction. It is observed that deicing salts increase the sensitivity of silicate minerals to ASR, but the reason is less well known and several mechanisms could play a role:
* Anion exchange in calcium aluminates leading to the formation of Friedel's or Kuzel's salts (chloroaluminate, AFm phases), simplified as: Cl– + AFm–OH → AFm–Cl + OH–
* However, this effect is counteracted by other reactions occurring with AFm, a.o. the following ones: 
** AFt + OH– → AFm (reaction favoring delayed ettringite formation, DEF)
** AFt + Cl– → Friedel's salt + SO42– + OH– 
* Effect of ionic strength (IS) on the solubility of different solid phases in concrete
** Reference: 
* Physical effect due to an increase of the concrete porosity where deicing salts penetrate
* Chatterji hypothesis of ultrafiltration of ions selectively penetrating into the aggregate:  Ca2+ and Cl– remaining out of the aggregates while only Na+ and OH– could only penetrate inside the porous silica network to form the soluble alkali gel (effect of selective membrane played by the gel or the porous structure of amorphous silica).
* Certainly not simply the direct reaction of NaCl or KCl with portlandite (implausible route, closed door): . Indeed, the equilibrium of this reaction is strongly displaced to the left because of the low solubility of portlandite.
* and maybe other totally unsuspected ways, or entrance doors,  still exist to explain the effect of deicing salts on ASR. 
* ...
Shinkolobwe (talk) 18:20, 29 April 2020 (UTC)
thread_title: Effect of deicing salts on ASR

message: * Large civil engineering structures: bridges, dams, nuclear power plants, ...
* Effects of earthquakes
* Shear walls tests
* ...
In advance, thank you for developing some aspects your are familiar with and adding relevant references and supporting didactic materials (photographs, technical diagrams, figures, tables, ...). Shinkolobwe (talk) 14:37, 28 April 2020 (UTC)
thread_title: Structural stability

message: Most sources outside wikipedia describe "Concrete Cancer" as corrosion of steel reinforcement, not ASR. At best there are different types of "concrete cancer"; perhaps the term is used to describe different phenomena in different parts of the world. At worst, this page is simply wrong. 
I believe redirecting "Concrete Cancer" to this page is a mistake. Pjaymes (talk) 14:39, 5 September 2023 (UTC)
replies: text: I understand your remark. Concrete cancer is a colloquial term poorly defined and bearing several possible meanings. It deals with concrete pathologies affecting the reinforced concrete structures durability. Concrete degradation is often driven by internal expansive reactions leading to the formation of cracks in reinforced concrete and spalling at its surface. So the corrosion of steel reinforcement is not the only type of concrete cancer: any internal expansive reaction (with considerable swelling inside the concrete) severely damaging concrete structures may also deserve this name, as it is the case for the alkali–silica reaction, also widely known as concrete cancer in the literature.Laura Kemp (8 July 2007) "The Millennium Stadium is suffering from concrete cancer, we can reveal", Wales on Sunday. This is justified by the intrinsic nature of the degradation mechanism itself directly affecting the concrete matrix integrity. So this colloquial term is not restricted to the only rebar corrosion. To resolve the question you have raised about this ambiguous expression, I have converted the page Concrete cancer from a Redirect to a Disambiguation page. Best regards, Shinkolobwe (talk) 14:04, 7 September 2023 (UTC)
thread_title:  Concrete Cancer?