A honeycomb structure includes a honeycomb structure body including porous partition walls defining a plurality of cells serving as fluid passages extending from an inflow end face to an outflow end face. The partition walls have a porosity of 45 to 65%; the open frontal area of the pores having an equivalent circle diameter of 10 μm or more, of the pores open on the surface of each partition wall, is 20 to 50%; the pore density of the pores having an equivalent circle diameter of 10 μm or more is 200 to 1,000 pores/mm.sup.2; the median opening diameter of the pores having an equivalent circle diameter of 10 μm or more is 40 to 60 μm; the circularity of the pores having an equivalent circle diameter of 10 μm or more is 1.8 to 4.0; and the partition walls have a wet area of 16,500 μm.sup.2 or more.

A honeycomb structure includes a honeycomb structure body including porous partition walls defining a plurality of cells serving as fluid passages extending from an inflow end face to an outflow end face. The partition walls have a porosity of 45 to 65%; the open frontal area of the pores having an equivalent circle diameter of 10 μm or more, of the pores open on the surface of each partition wall, is 20 to 50%; the pore density of the pores having an equivalent circle diameter of 10 μm or more is 200 to 1,000 pores/mm.sup.2; the median opening diameter of the pores having an equivalent circle diameter of 10 μm or more is 40 to 60 μm; the circularity of the pores having an equivalent circle diameter of 10 μm or more is 1.8 to 4.0; and the partition walls have a wet area of 16,500 μm.sup.2 or more.

The manufacturing method of the honeycomb structure includes a mounting step of mounting an extruded honeycomb formed body on a firing setter disposed on a shelf plate, and a firing step of firing the honeycomb formed body mounted on the firing setter to form the honeycomb structure, and in the mounting step, the firing setter is used in which a value obtained by dividing an area of a formed body end face of the honeycomb formed body by an area of a honeycomb mounting surface of the firing setter which faces the formed body end face and at least a part of which comes in contact with the formed body end face is in a range of 2.5 to 20.0.

The manufacturing method of the honeycomb structure includes a mounting step of mounting an extruded honeycomb formed body on a firing setter disposed on a shelf plate, and a firing step of firing the honeycomb formed body mounted on the firing setter to form the honeycomb structure, and in the mounting step, the firing setter is used in which a value obtained by dividing an area of a formed body end face of the honeycomb formed body by an area of a honeycomb mounting surface of the firing setter which faces the formed body end face and at least a part of which comes in contact with the formed body end face is in a range of 2.5 to 20.0.

The manufacturing method of the honeycomb structure includes a raw material preparing step of adding the powder of porous silica as the inorganic pore former to a forming raw material and kneading the forming raw material to prepare the kneaded forming raw material, an extruding step of extruding the obtained forming raw material to form a honeycomb formed body, and a firing step of firing the extruded honeycomb formed body to form a honeycomb structure containing a cordierite component, and an amount of oil to be absorbed by the porous silica to be added to the forming raw material is in a range of 50 to 190 ml/100 g, and a BET specific surface area of the porous silica is in a range of 340 to 690 m.sup.2/g.

The manufacturing method of the honeycomb structure includes a raw material preparing step of adding the powder of porous silica as the inorganic pore former to a forming raw material and kneading the forming raw material to prepare the kneaded forming raw material, an extruding step of extruding the obtained forming raw material to form a honeycomb formed body, and a firing step of firing the extruded honeycomb formed body to form a honeycomb structure containing a cordierite component, and an amount of oil to be absorbed by the porous silica to be added to the forming raw material is in a range of 50 to 190 ml/100 g, and a BET specific surface area of the porous silica is in a range of 340 to 690 m.sup.2/g.

Methods of manufacturing a cementitious structure, such as a structure for supporting a wind turbine, include additively printing, via an additive printing device, one or more contours that include a cementitious material so as to form a cementitious structure in a layer by layer manner such that a first portion of the plurality of contours comprises a first plurality of contour coupling features that engage with a second plurality of contour coupling features of a second portion of the plurality of contours.

The present invention relates to a process of fabricating a multi-layer composite structure by 3D printing, said composite structure comprises at least one cured mortar layer formed by curing of a mortar composition, and at least one polyurethane layer formed by polymerization of a first polyurethane forming composition, wherein said mortar composition and said first polyurethane forming composition are dispensed individually and simultaneously via adjacent printing nozzles. The mortar composition is optionally modified by a second polyurethane forming composition.

A honeycomb structure includes a central area and a reinforced outer peripheral area. A reference boundary cell with an inner wall orthogonal to an imaginary straight line, adjacent to the honeycomb center, and thinner than an outer wall adjacent to the honeycomb periphery has a reference wall different in wall thickness from the other three cell walls among the remaining four cell walls excluding the inner wall and the outer wall. The honeycomb structure includes a reference Y-shaped unit having the reference wall, the outer wall, and a cell wall. The honeycomb structure includes a plurality of Y-shaped units extending in the same directions as the reference Y-shaped unit. For every Y-shaped unit in the central area and the reinforced outer peripheral area of the honeycomb structure, the cell walls of each Y-shaped unit has an equal wall thickness.

A ceramic honeycomb structure comprising a ceramic honeycomb body having pluralities of longitudinal flow paths partitioned by square-lattice-cross-sectioned cell walls, and an outer peripheral wall formed on an outer periphery of the ceramic honeycomb body; the outermost peripheral cell wall of the ceramic honeycomb body having an outer peripheral surface shape reflecting the square lattice shapes of the cell walls; the thickness of the outer peripheral cell wall being larger than the thickness of the cell walls; and the outer peripheral wall being formed to cover an outer peripheral surface of the outer peripheral cell wall.