Nano-modified alkali-activated cementitious materials for rapid repair
View Patent ↗A nano-modified dry-mixed alkali-activated cementitious, or one-part geopolymer cement (OPgC), material with high early strength is provided for rapid repair of cement-based infrastructure components. The OPgC may include an aluminosilicate rich material, an alkali material and a nano-modifier, and optionally include other functional admixtures and fibers. The OPgC can be freshly mixed with water to obtain a repairing material. The OPgC may mix with water and fine or coarse aggregate to form mortar or concrete. The OPgC can be an alternative binding matrix for the development of an environmentally friendly and cost effective rapid repair material.
1. A nano-modified dry-mixed alkali-activated cementitious material for rapid repair, comprising an aluminosilicate material, an alkali material and a nanoparticle material, wherein the aluminosilicate material comprises at least feldspar in an amount of 1-25% w/w of the total aluminosilicate material and nepheline in an amount of 1-25% w/w of the total aluminosilicate material, and wherein the alkali material is present in an amount of 1-15% w/w of the total aluminosilicate material, and wherein the cementitious material attains a 1-day compressive strength of no less than 14 MPa.
2. The cementitious material of claim 1 , wherein the aluminosilicate material further comprises one or more components selected from pozzolans, blast furnace slag and ground granulated blast furnace slag, slag, steel slag and phosphorus slag, ash from municipal solid waste incinerator, fly ash, and metakaolin.
3. The cementitious material of claim 2 , wherein the aluminosilicate material comprises ground granulated blast furnace slag in an amount of at least 20% w/w of the total aluminosilicate material.
4. The cementitious material of claim 3 , wherein the ground granulated blast furnace has an average grain size of less than 50 microns.
5. The cementitious material of claim 2 , wherein the aluminosilicate material comprises fly ash in an amount of 0-80% w/w of the total aluminosilicate material.
6. The cementitious material of claim 5 , wherein the fly ash has an average grain size of less than 50 microns.
7. The cementitious material of claim 2 , wherein the aluminosilicate material comprises metakaolin in an amount of 0-25% w/w of the total aluminosilicate material.
8. The cementitious material of claim 7 , wherein the metakaolin has an average grain size of less than 50 microns.
9. The cementitious material of claim 1 , wherein the alkali material comprises at least one member selected from potassium hydroxide and sodium hydroxide.
10. The cementitious material of claim 1 , wherein the alkali material is at least one member selected from the group consisting of potassium hydroxide and sodium hydroxide, and the cementitious material further comprises sodium silicate and/or potassium silicate in a total amount of 0-20% w/w of the total aluminosilicate material.
11. The cementitious material of claim 1 , wherein the nanoparticle material comprises at least one of nano-silica, nano-alumina, nano-clay and silica fume.
12. The cementitious material of claim 11 , wherein the nanoparticle material is present in an amount of 1% to 5% w/w of the total weight of the cementitious material.
13. The cementitious material of claim 11 , wherein the nanoparticle material has a size of less than 500 nm.
14. The cementitious material of claim 1 further comprises at least one fibers selected from polyvinyl alcohol (PVA), polypropylene (PP) and polyethylene terephthalate (PET) fibers.
15. The cementitious material of claim 14 , wherein the fibers have a length of less than 12 mm and a diameter of less than 50 microns.
16. The cementitious material of claim 1 , wherein the cementitious material is freshly mixed with water before application.
17. The cementitious material of claim 1 , wherein the cementitious material is further mixed with aggregates and water to form mortar and concrete.