A precast concrete beam A beam for use in construction of a long span bridge structure comprising: a reinforcing member having a geometric configuration selected from a group consisting of: a “U” tub beam with composite deck system; a decked I-beam; and an adjacent box beam; said geometric configuration formed of a UHPC mix having: an initial compressive strength, f′.sub.ci=10.0 ksi; a compressive strength at service, f′.sub.c=17.4 ksi; a modulus of elasticity of concrete, E.sub.c=6500 ksi; a residual rupture stress, f.sub.rr=0.75 ksi; and a concrete unit weight, w.sub.c=0.155 kcf; and
said UHPC mix further comprises a plurality of discontinuous fibers distributed randomly throughout a concrete matrix, said plurality of discontinuous fibers formed of a material selected from the group consisting of: steel; polypropylene; nylon; polyvinyl alcohol; polyolefin; polyethylene; polyester; acrylic; aramid; carbon; silica glass; basalt glass; glass fiber-reinforced polymer; and basalt fiber-reinforced polymer.

A precast concrete beam A beam for use in construction of a long span bridge structure comprising: a reinforcing member having a geometric configuration selected from a group consisting of: a “U” tub beam with composite deck system; a decked I-beam; and an adjacent box beam; said geometric configuration formed of a UHPC mix having: an initial compressive strength, f′.sub.ci=10.0 ksi; a compressive strength at service, f′.sub.c=17.4 ksi; a modulus of elasticity of concrete, E.sub.c=6500 ksi; a residual rupture stress, f.sub.rr=0.75 ksi; and a concrete unit weight, w.sub.c=0.155 kcf; and
said UHPC mix further comprises a plurality of discontinuous fibers distributed randomly throughout a concrete matrix, said plurality of discontinuous fibers formed of a material selected from the group consisting of: steel; polypropylene; nylon; polyvinyl alcohol; polyolefin; polyethylene; polyester; acrylic; aramid; carbon; silica glass; basalt glass; glass fiber-reinforced polymer; and basalt fiber-reinforced polymer.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Type I/II Portland cement, and a fine and coarse silica sand. The ratio of Portland cement to fine sand or fine clay, may be approximately 1.02. The ratio of water-to-binder (Portland cement and SCM) may be approximately 0.55, and the ratio of water-to-powder (binder plus fine clay smaller than 75 microns) can be approximately 0.416. Included with the water and binder/powder mix is an admixture. According to one embodiment, the admixture can include a water reducing admixture, or plasticizer. The fine clay within the aggregate material is unprocessed, and the binder material is approximately 84 to 90 percent cement and 10 to 16 percent SCM. The unprocessed clay, or fine sand, does not undergo any heating, any chemical modification or sifting before being added to the aggregate material.

A 3D printable clay-based mortar cementitious ink includes a blend of commercially available Type I/II Portland cement, and a fine and coarse silica sand. The ratio of Portland cement to fine sand or fine clay, may be approximately 1.02. The ratio of water-to-binder (Portland cement and SCM) may be approximately 0.55, and the ratio of water-to-powder (binder plus fine clay smaller than 75 microns) can be approximately 0.416. Included with the water and binder/powder mix is an admixture. According to one embodiment, the admixture can include a water reducing admixture, or plasticizer. The fine clay within the aggregate material is unprocessed, and the binder material is approximately 84 to 90 percent cement and 10 to 16 percent SCM. The unprocessed clay, or fine sand, does not undergo any heating, any chemical modification or sifting before being added to the aggregate material.

The present invention provides a geopolymer cement, comprising: a geopolymer binder; and a setting control composition comprising: a viscosity control agent, a polymeric binder, and a retarding additive. The invention also relates to a geopolymer concrete comprising the geopolymer cement of the invention and aggregate material. The invention further relates to a method for controlling open time in a geopolymer composition, wherein a sufficient quantity of the setting control composition is added such that the open time is between 30 and 120 minutes. The present invention provides particular uses in construction of walls, flooring, and roofing, especially lightweight prefabricated panels intended to be used as structural, insulating or cladding elements.

The present invention provides a geopolymer cement, comprising: a geopolymer binder; and a setting control composition comprising: a viscosity control agent, a polymeric binder, and a retarding additive. The invention also relates to a geopolymer concrete comprising the geopolymer cement of the invention and aggregate material. The invention further relates to a method for controlling open time in a geopolymer composition, wherein a sufficient quantity of the setting control composition is added such that the open time is between 30 and 120 minutes. The present invention provides particular uses in construction of walls, flooring, and roofing, especially lightweight prefabricated panels intended to be used as structural, insulating or cladding elements.

A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

A concrete composition and method include a portion of fine aggregate bearing a coating of a polymer or an admixture, which may be a continuous coating layer or a layer of powdered, discrete particles embedded in a binder. The polymeric coating may be an admixture in powdered form, a super absorbent polymer (insoluble in water, but absorbing water), or another polymer such as the acrylamides, co-polymers thereof, polyacrylamides, or the like (soluble in water). The coating absorbs water, but particles are too small to form significant voids. Water is absorbed into the concrete mix in far greater proportions (e.g. w/c ratio over 0.5) improving workability, doubling workability time, and improving ultimate compressive stress (strength).

The present invention relates to very high workable yet controllable concrete mix design, admixture composition, and process for placing concrete. The mix design relates to particular aggregate/cement ratios and types which are characteristic of ready mix concrete (RMC), which provide high fluidity reminiscent of self-consolidating concrete (SCC), and which provides advantages over both RMC and SCC in terms of ease and speed in placement and finishability at the construction site placement zone, regardless of whether into a horizontal formwork (e.g., for slabs, floors) or into vertical formwork (e.g., for blocks, walls, columns, etc.), without loss of control and without generating high risks of segregation even when small amounts of water are added at the size to facilitate finishing of the concrete surface. An inventive admixture combination which enables this unique design involves two different polycarboxylate comb polymers in combination with two specific viscosity modifying agents, and this combination provides highly workable concrete to be placed in a controlled, efficient manner.

The present invention relates to very high workable yet controllable concrete mix design, admixture composition, and process for placing concrete. The mix design relates to particular aggregate/cement ratios and types which are characteristic of ready mix concrete (RMC), which provide high fluidity reminiscent of self-consolidating concrete (SCC), and which provides advantages over both RMC and SCC in terms of ease and speed in placement and finishability at the construction site placement zone, regardless of whether into a horizontal formwork (e.g., for slabs, floors) or into vertical formwork (e.g., for blocks, walls, columns, etc.), without loss of control and without generating high risks of segregation even when small amounts of water are added at the size to facilitate finishing of the concrete surface. An inventive admixture combination which enables this unique design involves two different polycarboxylate comb polymers in combination with two specific viscosity modifying agents, and this combination provides highly workable concrete to be placed in a controlled, efficient manner.