The cementitious mixture includes cement with a concentration of between about 5 wt % and about 20 wt %; powdered glass with a concentration of between about 5 wt % and about 35 wt %; fly ash with a concentration of between about 20 wt % and about 40 wt %; sand with a concentration of between about 18 wt % and about 25 wt %; a poly(carboxylate ether)-based superplasticizer with a concentration of between about 0.8 wt % and about 1.2 wt %; and water with a concentration of between about 14 wt % and about 16 wt %. Alternatively, the fly ash may be replaced with ground granulated blast furnace slag (GGBFS). The powdered glass is preferably powdered recycled glass cullet. The glass cullet may be ground to have an average particle size of about 10 m or less. The sand may be red dune sand, and the cement may be Portland cement or white cement. The cementitious may also include polyvinyl alcohol (PVA) microfibers.

A method of producing green concrete, and particularly to green concrete with Portland cement (C), natural basaltic volcanic ash pozzolan (VA), and microsilica (MS). The green concrete described herein is a high-performance green concrete composition that partially substitutes Portland Cement (C) and can further include fine aggregates (FA) and coarse aggregates (CA), water (W), and a super plasticizer (SP). The green concrete described herein can be cured at ambient temperature and can have a better compressive strength and durability properties, and high shrinkage resistance as compared to conventional concrete and, as such, can be used for high performance applications.

A green concrete composition comprising: a binder component comprising Portland cement, natural basaltic volcanic ash pozzolan, and colloidal nano-sized silica particles; an aggregate component comprising fine aggregates and coarse aggregates; water; and a super plasticizer.

An ultra-high-performance cement composites comprising cement, a polycarboxylate ether-based superplasticizer, fly ash, silica fume, reclaimed asphalt pavement granules, water and red sand. A very low water-to-binder ratio could be obtained using the polycarboxylate ether-based superplasticizer that overcomes the hydrophobic properties of reclaimed asphalt pavement and yields an ultra-high-performance cement composite.

Embodiments of the disclosure provide a printable cementitious composition comprising a cement binder, an aggregate, at least one pozzolanic additive, an accelerator, water, and nanoclay.

Mineral fines reduce OPC content in concrete, mortar and other cementitious compositions, typically in combination with a pozzolanically active SCM. Mineral fines can replace and/or augment a portion of hydraulic cement and/or fine aggregate. Mineral fines can replace a portion of cement binder and fine aggregate as an intermediate that fills a size void between largest cement particles and smallest fine aggregate particles. Supplemental lime can enhance balance of calcium ions in the mix water and/or pore solution. Supplemental sulfate can address sulfate deficiencies caused by high clinker reduction, use of water reducers and/or superplasticizers, and SCMs containing aluminates. Concentrated or pure carbon dioxide (CO.sub.2) can be used to passivate alkaline values in highly alkaline materials, such as concrete washout fines, CKD, class C flyash, incinerator ash, bottom ash, or biomass ash. CO.sub.2 passivation or sequestration can be carried out before, during or after forming an initial concrete mix.

A dry mineral binder composition includes cement and mineral fillers for the manufacture of molded parts by way of 3D printing. The binder composition additionally contains at least one aluminum sulfate-based accelerator, at least one polycarboxylate ether-based super-plasticizer and at least one rheology additive.

The present invention discloses a crack-resistant ultra-high performance concrete (UHPC) for underground engineering in water-rich strata, preparation method, and application thereof, belonging to the technical field of building materials. The concrete is prepared from the following raw materials in parts by weight: 550-650 parts of cement, 140-180 parts of fly ash, 120-150 parts of silica fume, 200-300 parts of calcined shield tunnel slag, 30-50 parts of micron-scale magnesium oxide, 30-50 parts of nano-scale magnesium oxide, 30-50 parts of rheology-modifying material, 800-1000 parts of lightweight aggregate, 4-8 parts of water reducer, and 50-200 parts of water. The rheology-modifying material has a fluidity ratio of 106%. The present invention incorporates calcined shield tunnel slag, micron/nano-scale magnesium oxide, and lightweight aggregate into the UHPC, which effectively suppresses shrinkage and reduces crack formation.

A method of making high performance concrete, the method may include adding ground glass powder (GP), nanosilica (nS) powder, cement, silica fume, fly ash, and sand to create a homogenized mixture. The method may also include homogenizing the mixture by mixing and adding water and superplasticizer to the homogenized mixture to obtain a slurry. The method may also include mixing the slurry until a high flowability mixture is obtained. The method may then include adding a first microsteel fiber (T1) to the high flowability mixture; adding a second microsteel fiber (T3) to the high flowability mixture; adding a third microsteel fiber (T4) to the high flowability mixture; and casting the high flowability mixture.

A novel cement composition for 3D printing including has 90% to 99.5% by weight of one or more cements selected from a Portland cement, an aluminous cement, a sulphoaluminous cement and a prompt natural cement; and has 0.5% to 10% by weight of a silicoaluminous filler having a specific surface area of at least 5 m.sup.2/g, as well as a method for implementing the composition.