Graphene oxide fine aggregate in cement composites
A cementitious nano-engineered method and resultant composite includes a modified aggregate material configured from a plurality of fine aggregate particles (FAg) particles pretreated with a graphene oxide (GO), wherein the graphene oxide (GO) is further arranged as a plurality of crosslinked structures that arranges for a refined interfacial zone (ITZ) with a thickness of 3 μm to 10 μm; and a water/cement (w/c) ratio content configured with the modified aggregate material. The interface of modified aggregate and a cementitious phase largely determines the mechanical properties and durability performances of cement mortar and concrete. Moreover, the methods and composites also provide for a targeted and more efficient approach to develop smart cement composites through nanoengineering of the interfacial transition zone.
1 . A cured cementitious composite, comprising:
a modified aggregate material, comprising a plurality of modified fine aggregate (modified FAg) particles that are bound, in a spatial distribution, within a hardened paste also comprising a cement and water
wherein:
the modified FAg particles comprise FAg particles coated with a graphene oxide (GO) as a GO layer that is adsorption bonded on surfaces of the FAg particles,
the modified FAg particles are bound to the hardened paste by respective refined interfacial transition zones (refined ITZs) having a plurality of crosslinked structures of the graphene oxide (GO) layer and a plurality of crosslinks of structures of the GO layer with structures of the hardened paste, and
the refined interfacial transition zone (ITZs) have a thickness of 3 μm to 10 μm.
2 . The cementitious composite of claim 1 , wherein the modified aggregate material is configured with a porosity of about 18 percent and with a plurality of pores having an average pore diameter of about 34 nm.
3 . The cementitious composite of claim 1 , wherein the modified aggregate material further comprises a plurality of graphene fine aggregate conductive particles.
4 . The cementitious composite of claim 3 , wherein up to 62.2% of the surface area of the graphene fine aggregate conductive particles is covered by graphene and with an average thickness of about 8.8 nm.
5 . The cementitious composite of claim 3 , wherein the conductivity of the graphene fine aggregate conductive particles is up to 180 S/cm.
6 . The cementitious composite of claim 3 , wherein the plurality of graphene fine aggregate conductive particles include at least: i) a plurality of thermally conductive particles, or ii) a plurality of electrically conductive particles, or both i) and ii).
7 . The cementitious composite of claim 1 , wherein the fine aggregate particles (FAg) are selected from at least one of, or from any combination or sub-combination of a sand, a crushed aggregate, an agro-waste, and an industrial waste.
8 . The cementitious composite of claim 7 , wherein the sand is selected from at least one of, or from any combination or sub-combination of a siliceous sand, a carbonaceous sand, a dune sand, a granite sand, a waste foundry sand, and a basalt sand.
9 . The cementitious composite of claim 7 , wherein the crushed aggregate is selected from at least one of, or from any combination or sub-combination of a biochar, a crumb rubber, a waste plastic, a recycled glass, a recycled aggregate, a reclaimed asphalt pavement, a recycled brick, a recycled ceramic, a mining tailing, a coal fly ash, a bottom ash, and a biomass fly ash.
10 . The cementitious composite of claim 7 , wherein the agro-waste is selected from at least one of, or from any combination or sub-combination of a groundnut shell, an oyster shell, a cork, a coffee ground, a tobacco waste, a bagasse ash, a sawdust ash, and a municipal limestone.
11 . The cementitious composite of claim 7 , wherein the industrial waste is selected from at least one of, or from any combination or sub-combination of an air cooled slag, a steel slag, a copper slag, a blast furnace slag, a ferrochrome slag, an imperial smelting furnace slag, a palm oil clinker, a solid waste incineration fly ash or a bottom ash.
12 . A composite preparation method, comprising:
pre-adsorbing particles of a fine aggregate material with a graphene oxide in an aqueous dispersion, wherein an amount of the graphene oxide in the aqueous dispersion is from about 0.01 to 0.06 percent by weight of the total weight of water and graphene oxide (GO), such that the pre-adsorbing results in an aqueous dispersion of a modified fine aggregate material, the modified fine aggregate material comprising the particles of the fine aggregate material configured with pre-adsorption bonded layers of GO; and
adding to the aqueous dispersion of the modified aggregate material a water/cement (w/c) to obtain a ratio content of water/cement/modified fine aggregate material so as to result in a cementitious composite.
13 . The composite preparation method of claim 12 , further comprising curing the cementitious composite at a temperature range of about 20° C. with a humidity of greater than 95%.
14 . The composite preparation method of claim 12 , further comprising selecting the aggregate material from at least one of, or from any combination or sub-combination of a sand, a crushed aggregate, an agro-waste, and an industrial waste.
15 . The composite preparation method of claim 14 , wherein the sand is selected from at least one of, or from any combination or sub-combination of a siliceous sand, a carbonaceous sand, a dune sand, a granite sand, a waste foundry sand, and a basalt sand.
16 . The composite preparation method of claim 14 , wherein the crushed aggregate is selected from at least one of, or from any combination or sub-combination of a biochar, a crumb rubber, a waste plastic, a recycled glass, a recycled aggregate, a reclaimed asphalt pavement, a recycled brick, a recycled ceramic, a mining tailing, a coal fly ash, a bottom ash, and a biomass fly ash.
17 . The composite preparation method of claim 14 , wherein the agro-waste is selected from at least one of, or from any combination or sub-combination of a groundnut shell, an oyster shell, a cork, a coffee ground, a tobacco waste, a bagasse ash, a sawdust ash, and a municipal limestone.
18 . The composite preparation method of claim 14 , wherein the industrial waste is selected from at least one of, or from any combination or sub-combination of an air cooled slag, a steel slag, a copper slag, a blast furnace slag, a ferrochrome slag, an imperial smelting furnace slag, a palm oil clinker, a solid waste incineration fly ash or a bottom ash.