An extrudable cement-based material is formed from a mixture that includes cement in the range of about 40 to 90% by wet weight percent, a lightweight expanded aggregate in the range of about 10 to 60% by wet weight percent, a secondary material in the range of about 0.1 to 50% by wet weight percent, a reinforcement fiber in the range of about 1 to 20% by wet weight percent, a rheology modifying agent in the range of about 0.5 to 10% by wet weight percent, a retarder in the range of about 0.1 to 8% by wet weight percent, and water in the range of 10 to 60% of a total wet material weight.

Fibers to be added to concrete to improve its properties are coated with an alkali-insoluble polymer, to provide adhesion of the fibers to the concrete. In a further improvement, nanoparticles are dispersed in an alkali-soluble polymer coating, and this is used to coat the fibers. When the fibers are mixed into the concrete mix, the nanoparticles are dispersed throughout the concrete, avoiding problems from agglomeration of the nanoparticles if simply added to the concrete mix.

Printable cementitious compositions for additive manufacturing are provided, that have a fresh state and a hardened state. In fresh state, the composition is flowable and extrudable in the additive manufacturing process. In the hardened state, the composition exhibits strain hardening. In one variation, the strain hardening is represented by a uniaxial tensile strength of ?about 2.5 MPa, a tensile strain capacity of ?about 1%, and a compressive strength at 100 hours of ?about 20 MPa. In other variations, the composition includes Portland cement, a calcium aluminate cement, a fine aggregate, water, a high range water reducing agent (HRWRA), and a polymeric fiber, as well as one or more optional components selected from: fly ash, silica flour, microsilica, attapulgite nanoclay, and/or hydroxypropylmethyl cellulose (HPMC). Methods of additive manufacturing with such compositions are also provided.

A system and method of constructing a 4D-printed ceramic object includes extruding inks including particles and polymeric ceramic precursors through a nozzle to deposit the inks on a heating plate, whereby a 3D-printed elastomeric object is formed on the heating plate, folding the 3D-printed elastomeric object into a complex structure to form a 4D-printed pre-strained elastomeric object, and converting the 4D-printed elastomeric object into the 4D-printed ceramic object.

A roofing tile composed of concrete material and a method for producing such a roofing tile. The concrete material contains a binder, a gravel, a light-weight aggregate, and added water. The roofing tile has at least one watercourse and a lateral interlocking joint having a covering fold and a water fold. The ratio of water to binder is less than 0.3, the light-weight aggregate is composed of a material that is hydrophobic and/or not hygroscopic, and the roofing tile has a density in the range of 1.6 g/cm.sup.3 to 1.9 g/cm.sup.3 after the hardening. The roofing tile has a thickness of 5 mm to 9 mm, preferably 7 mm to 8 mm, in the highly loaded regions, preferably in the region of the watercourse.

A manufacturing process of a concrete product includes: (1) extracting calcium from solids as portlandite; (2) forming a cementitious slurry including the portlandite; (3) shaping the cementitious slurry into a structural component; and (4) exposing the structural component to carbon dioxide sourced from a flue gas stream, thereby forming the concrete product.

According to embodiments, a batch mixture includes inorganic components, a non-polar carbon chain lubricant, and an organic surfactant having a polar head. The non-polar carbon chain lubricant and the organic surfactant are present in concentrations satisfying the relationship: B(C.sub.1(d+d.sub.0)+C.sub.2(f+f.sub.0))=SC, where: d.sub.0+d is an amount of non-polar carbon chain lubricant in percent by weight of the inorganic components, by super addition; f.sub.0+f is an amount of organic surfactant in percent by weight of the inorganic components, by super addition; B is a scaling factor; C.sub.1 is a scaling factor of the concentration of the non-polar carbon chain lubricant; and C.sub.2 is a scaling factor of the concentration of the organic surfactant. Embodiments provide that 3.6SC14.

A method for forming a structure through three-dimensional (3D) printing, the method comprising applying through a 3D printing apparatus one or more layers of a mortar composition, in which the mortar composition comprises a mortar powder and one or more epoxies. In addition, a mortar composition comprising a mortar powder and one or more epoxies for use in forming a structure through three-dimensional printing. The mortar powder may comprise a cement, such as a hydraulic cement, and an aggregate. The mortar powder may further comprise one or more admixtures. The one or more epoxies may comprise a polymeric resin, and may be bisphenol-based or water-based. Further, the mortar composition may also comprise a curing agent.

Provided are a cement mortar additive for extrusion molding, a cement mortar for extrusion molding, and an extrusion-molded product. The disclosed cement mortar additive for extrusion molding includes hydrogelated cellulose ether.

A system and method for producing a coal product from a carbon source material. The coal product may include a green carbon foam, a finished carbon foam, and/or a coal siding product. The system and method for producing a green carbon foam may involve pulverizing the carbon source material prior to processing the pulverized carbon source material to produce the green carbon foam using a float bath or an extruder. During production of the green carbon foam, the temperature of the float bath or extruder may be maintained at a temperature determined relative to the Gieseler fluidity properties of the carbon source material used.