This invention relates to three-dimensional printing. This invention in particularly relates to a method of fabricating a three-dimensional object using a support edifice and also using a mold material with structural additives. The support edifice is fabricated in the same crafting material as the final three-dimensional object in the same manner as the printing of the final three-dimensional object (mold and crafting in a layer by layer manner). This method enables the support edifice to also transform during post processing in the same manner as the final three-dimensional object, thus supporting the object until finished. The system for fabricating the object comprises a dual printhead comprising a first dispensing nozzle for depositing the filament material in a flowable fluid form and a second dispensing nozzle for depositing the crafting medium, which is in a paste form. The printhead can also include a heating system or a drying apparatus. The three-dimensional imaging process for making objects, preferably metal objects or ceramic objects, on a layer-by-layer basis under the control of a data processing system is disclosed. The printing of the three-dimensional object such as heavy objects or an object having different parts having a very thin gap or space. It is important to use different processing steps and/or material to print such three-dimensional objects. The present invention provides a solution by printing a support edifice comprising a special structural additive for the mold, and further the support edifice can be printed simultaneously while printing the mold and crafting-paste material on a layer-by-layer basis. The mold material is mixed with the structural additive. The structural additive is useful for prohibiting either fusing of the object with the support edifice, or in alternative embodiments, the fusing of one part of an object with another part of an object.

The invention provides a cross-flow separation element comprising a single-piece rigid porous support (2) having within its volume at least one channel (4.sub.1) for passing a flow of the fluid medium for treatment, which channel presents a flexuous flow volume (V1) defined by sweeping a generator section along a curvilinear path around a reference axis, and in that the reference axis does not intersect said generator section and is contained within the volume of the porous support.

An article of manufacture includes at least one concrete member formed from a concrete mix including a ternary mixture of pozzolanic materials. The ternary mixture includes: a combination of a first pozzolanic supplemental cementitious material and a second pozzolanic supplemental cementitious material; and a pozzolanic supplemental aggregate material.

A ceramic slurry for forming a ceramic article includes a binder, a first plurality of ceramic particles having a first morphology, a second plurality of ceramic particles having a second morphology that is different from the first morphology; and a photoinitiator. A method for using this slurry for fabricating ceramic articles is presented as well.

A multi-component mortar system including a component A and a component B wherein, component A includes aluminous cement, at least one set inhibitor, at least one mineral filler and water, and component B includes an initiator system for the set-inhibited aluminous cement, at least one mineral filler and water. The multi-component mortar system is easy to use and suitable for repair and refurbishment and particularly for printing 3D structures.

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 membrane device comprising a porous ceramic member. The porous ceramic member comprises a first support portion operable to support an active layer and further comprises a second support portion. The second support portion has a higher D.sub.75 average pore size than the D.sub.75 average pore size of the first support portion. The second support portion comprises a lattice structure that has a porosity percentage of ?40%. The porous ceramic member has a tensile strength operable to withstand feed application pressure of ?100 kPa (1 bar).

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.

There is provided a solid cement reactant comprising a dehydrated magnesium phosphate, and/or an amorphous or partially amorphous magnesium phosphate, and/or Farringtonite.

A method of placing a flowable construction material including a hydraulic binder for building structural components layer-by-layer, such as for 3D concrete printing, the method including preparing a fresh flowable construction material made of Portland cement, fine limestone filler materials, fine sands, water, and water reducing admixture and possibly a set or hardening accelerating admixture, conveying the flowable construction material to a deposition head, placing the construction material through an outlet of the deposition head in order to form a layer of construction material, before placing the construction material, adding a rheology-modifying agent to the construction material so that the placed material has an increased yield stress when compared to the material during the conveying step.