Compositions of steel-microfiber reinforced ultra high performance concrete (UHPC) using recycled glass powder and processes for making the same
View Patent ↗The invention relates to processes for making steel-microfiber reinforced ultra high performance concrete using recycled glass powder and articles made from the same. The invention includes a process of mixing first dry constituents of fine aggregate and cement to yield a first dry mix, followed by mixing with second dry constituents consisting of 2.5-6.0 micron recycled glass powder, silica fume, silica flour, cenospheres, and optionally microinclusions to obtain a UHPC dry mix, followed by adding water only, with further mixing, then adding a superplasticizer admix and a water-reducing admix to obtain ultra high performance concrete paste, followed by adding steel microfibers that are 13 mm×0.2 mm.
1 . A process for making a microfiber-containing hydrated ultra high performance concrete (UHPC) paste, comprising:
(i). preparing a UHPC dry mix by mixing sand 28-32 weight %, cement 28-32 weight % having a Blaine fineness of about 3000-4500 cm 2 /g, silica fume 12-14 weight %, silica flour 7.0-9.0 weight %, and microinclusions, wherein the microinclusions are selected from one or more the group consisting of 2.5-6.0 micron recycled glass powder, cenospheres, ceramic spheres, steel shavings, ceramic whiskers, mineral fibers, wollastonite, ultra-high molecular weight polyethylene (UHMWPE) microfibers, and carbon fibers;
(ii). preparing a hydrated UHPC paste by mixing water into the UHPC dry mix, followed by mixing a high-range water-reducing admixture (HRWRA); and
(iii). mixing steel microfibers 13 mm×0.2 mm, 5-10% weight % into the hydrated UHPC paste to obtain a hydrated microfiber UHPC paste;
wherein a total of all weight % equals 100%.
2 . The process according to claim 1 , wherein total mixing time is 5-10 minutes.
3 . The process according to claim 1 , wherein said high-range water-reducing admixture is a combination of two or more admixtures selected from a superplasticizer liquid admixture, a water-reducing liquid admixture, and mixtures thereof, and wherein the high-range water-reducing admixture combination has a density of 1.04-1.06 g/cc.
4 . The process according to claim 1 , wherein the microinclusions are 1.0-25.0 weight %.
5 . The process according to claim 1 , wherein the process is performed in a redi-mix truck at a volume of 8-11 cu. yds.
6 . The process according to claim 1 , wherein the process is performed in a stationary mixer at a volume of 1-3 cu. yds.
7 . A microfiber-containing hydrated ultra high performance concrete (UHPC) paste made according to the process of claim 1 .
8 . The process of claim 1 , comprising the step of forming the hydrated microfiber UHPC paste into an article.
9 . An article made according to the process of claim 8 .
10 . The article according to claim 9 , wherein the article is a component selected from the group consisting of: an overlay, a joint fill, a beam end-cap, a plate, a channel, a pipe, a tube, an I-beam section, an H-beam component, a wide-flange (WF) section, a smooth column, a fluted column, a connector, a panel, a vehicle armor, a ballistic armor, a blast-resistant panel, a portable panel, a thin armor panel, a forced entry resistant structural element, a wall panel, a roofing tile, a floor tile, a kitchen and bath countertop, a laboratory bench top, a hurricane and tornado resistant structural wall, a bollard, a planter, a sea-wall component, a drainage tile, a pipe and ditch component, an underflooring, a wall tile, a stepping stone, a planter, a paver, a truss, a joist, a rafter, a support gusset, a decking, a footer, a mounting pad, a post and pole anchor block, a precast water conduit, a precast sewage pipe, a precast pipe connector, a concrete block, a brick, a refractory brick, a fireplace liner, a veneer, an oil and gas well casing, a seawall, a sea barrier block and form, an undersea piling, an undersea mounting pad, a harbor dock, a precast highway slab, a precast railroad tie, a precast parking block, a precast jersey barrier, a street curb, a sidewalk, a driveway, a drive apron, a warehouse flooring slab, a storage tank pad, a power station tower, and a power station dam.
11 . The article according to claim 9 , wherein the article is a component selected from the group consisting of: a vehicle armor component, a ballistic armor component, a blast-resistant panel, a portable panel, a thin armor panel, a forced entry resistant structural element, an armored roofing tile, a ballistic wall panel, a ballistic floor tile, a hurricane and tornado resistant structural element, and combinations thereof.
12 . The article according to claim 10 , further comprising mats of steel strands of diameter less than about 2.5 mm affixed to a tensile-load carrying face of said article.
13 . The process according to claim 1 , comprising forming said hydrated microfiber UHPC paste in the shape of a component, and curing said component by heating and/or hydrating with heating, and/or applying voltage to cure said component.
14 . The process according to claim 13 , comprising curing said component by: (i) placing in an environment of approximately 100% relative humidity for about seven days at ambient temperature, (ii) submersing in water of approximately 85° C. to about 91° C. for about three to about five days, and (iii) heating in air at approximately 85° C. to about 91° C. for about one to about two days, wherein, said cured composition component becomes crystalline and has a compressive strength of at least 4,000-21,500 psi.
15 . A heat-cured component made according to the process of claim 13 .
16 . The article according to claim 9 , wherein the article has wire connectors connected to the steel microfibers for providing a voltage-heating voltage supply to generate a heated ultra high performance concrete article.
17 . The article of claim 16 , wherein the heated ultra high performance concrete article is selected from one of the group consisting of: a heated floor tile, a heated wall panel, a heated roofing tile, a heated sidewalk, and a heated bridge deck.