Mitigation of alkali-silica reaction in concrete using readily-soluble chemical additives
A manufacturing method includes: (1) incorporating at least one soluble, calcium, magnesium, or other divalent cation-containing additive into a concrete mixture including aggregates prone to alkali-silica reaction; and (2) curing the concrete mixture to form a concrete product.
1. A method of manufacture, the method comprising:
incorporating at least one water-soluble divalent cation salt-containing additive into a concrete mixture, the concrete mixture comprising aggregates prone to alkali-silica reaction; and
curing the concrete mixture to form a concrete product, wherein curing the concrete mixture includes forming divalent cation-containing reaction products at an interface between the aggregates and a cementitious pore solution within the concrete mixture.
2. The method of claim 1 , wherein the aggregates comprise silica.
3. The method of claim 1 , wherein the aggregates comprise at least one of silicate glass, strained quartz, or microcrystalline quartz.
4. The method of claim 1 , further comprising identifying the aggregates as prone to an alkali-silica reaction, and wherein incorporating the water-soluble divalent cation salt-containing additive is responsive to identifying the aggregates prone to the alkali-silica reaction.
5. The method of claim 1 , wherein incorporating the water-soluble divalent cation salt-containing additive includes adjusting an amount of the water-soluble divalent cation salt-containing additive according to at least one of: a) an amount of the aggregates or b) reactivity of the aggregates.
6. The method of claim 1 , further comprising:
subjecting the aggregates to pre-treatment to form pre-treated aggregates;
incorporating the pre-treated aggregates into the concrete mixture; and curing the concrete mixture to form the concrete product,
wherein subjecting the aggregates to pre-treatment includes exposing the aggregates to a solution comprising a water-soluble divalent cation salt-containing additive, thereby forming a divalent cation-containing interfacial barrier at least partially covering the aggregates.
7. The method of claim 1 ,
wherein the water-soluble divalent cation salt-containing additive is a calcium salt-containing additive, and
curing the concrete mixture to form a concrete product forms a calcium-containing interfacial layer at least partially covering the aggregates.
8. The method of claim 7 , wherein the calcium-containing interfacial layer comprises calcium-silicate-hydrate and calcium carbonate.
9. The method of claim 7 , wherein the aggregates comprise silica.
10. The method of claim 7 , wherein the aggregates comprise at least one of silicate glass, strained quartz, or microcrystalline quartz.
11. The method of claim 7 , further comprising identifying the aggregates as prone to an alkali-silica reaction, and wherein incorporating the calcium salt-containing additive is responsive to identifying the aggregates prone to the alkali-silica reaction.
12. The method of claim 7 , wherein incorporating the calcium salt-containing additive includes adjusting an amount of the calcium salt-containing additive according to at least one of: a) an amount of the aggregates or b) reactivity of the aggregates.
13. The method of claim 7 , wherein the calcium salt-containing additive comprises calcium nitrate, calcium chloride, calcium nitrite, or any combination thereof.
14. The method of claim 7 , wherein the concrete mixture comprises a cement, and the calcium salt-containing additive is incorporated into the concrete mixture in an amount of at least 1% by mass, relative to a mass of the cement.
15. The method of claim 14 , wherein the calcium salt-containing additive is incorporated into the concrete mixture in an amount sufficient to attain an initial concentration of calcium ions in a pore solution of the concrete mixture of at least 30 mM.
16. The method of claim 1 ,
wherein the water-soluble divalent cation salt-containing additive is a magnesium salt-containing additive.
17. The method of claim 16 , wherein the curing the concrete comprises forming a magnesium-containing interfacial layer at least partially covering the aggregates.
18. The method of claim 16 , wherein the magnesium-containing additive comprises magnesium nitrate, magnesium nitrite, magnesium chloride, or any combination thereof.
19. A concrete product, comprising:
a binder;
aggregates dispersed within the binder;
and a calcium-containing interfacial layer at least partially covering the aggregates, wherein the calcium-containing interfacial layer comprises calcium-silicate-hydrate and calcium carbonate.
20. A concrete product, comprising:
a binder;
aggregates dispersed within the binder; and
a magnesium-containing interfacial barrier at least partially covering the aggregates wherein the magnesium-containing interfacial barrier comprises magnesium-silicate-hydrate and hydrated magnesium carbonate.