A monolithic ceramic body can comprise a first portion comprising a plurality of pores defining an interconnected network of pores, and a second portion integrally formed with the first portion and defining at least a portion of a perimeter surface of the monolithic ceramic body, wherein the second portion can include at least one complementary engagement structure.

In another embodiment, a porous ceramic assembly can comprise at least two of the monolithic ceramic bodies which are coupled to each other by a first complementary engagement structure and a second complementary engagement structure.

A monolithic ceramic body can comprise a first portion comprising a plurality of pores defining an interconnected network of pores, and a second portion integrally formed with the first portion and defining at least a portion of a perimeter surface of the monolithic ceramic body, wherein the second portion can include at least one complementary engagement structure.

In another embodiment, a porous ceramic assembly can comprise at least two of the monolithic ceramic bodies which are coupled to each other by a first complementary engagement structure and a second complementary engagement structure.

A ceramic porous body including: skeleton portions including an aggregate and at least one bonding material; and pore portions formed between the skeleton portions, the pore portions being capable of allowing a fluid to flow therethrough, wherein the pore portions have a pore volume ratio of pores having a pore diameter of from 10 to 15 m, of from 4 to 17% or more.

A method for producing a ceramic honeycomb structure including: plugging ends of cells on one of a first end face side and a second end face side in each of the cells of a ceramic honeycomb formed body that includes partition walls defining the cells extending from the first end face to the second end face; placing the ceramic honeycomb formed body on a shelf board with the first end face facing downward; arranging at least one lid member on the second end face of the ceramic honeycomb formed body so as to completely cover the second end face; and placing the ceramic honeycomb formed body together with the shelf board and the lid member in a firing furnace and firing the ceramic honeycomb formed body.

A honeycomb structure includes a pillar-shaped honeycomb structure body having a porous partition wall. The honeycomb structure body includes a plurality of cells defined by the partition wall so as to extend from a first end face to a second end face of the honeycomb structure body, the partition wall is formed by a porous body including a silicon phase as a main phase and an oxide, and the oxide includes a first oxide made of an alkali earth metal oxide, Al.sub.2O.sub.3, and SiO.sub.2.

A pillar-shaped honeycomb structure body of a honeycomb structure includes a circumferential cell structure, a central cell structure and a boundary wall therebetween. On a surface orthogonal to the cells there are a circumferential reinforcing region having the partition wall thicker than a basic partition wall thickness in the circumferential cell structure and existing outside a range of a distance from a centroid of the surface; and at least one of a first boundary reinforcing region having the partition wall thicker than the basic partition wall thickness and existing in a range of a distance from the centroid within a range of the circumferential cell structure and a second boundary reinforcing region having the partition wall thicker than a basic partition wall thickness in the central cell structure and existing outside of a range of a distance from the centroid within a range of the central cell structure.

The circumference coating material fills a recessed groove that is formed on a circumferential surface of a honeycomb fired body and extends an axial direction at which a part of cells are opened to the outside and to cover the circumferential surface, thereby forming a circumferential wall on the circumferential surface of a honeycomb structure, and the circumference coating material includes colloidal silica in a part of raw materials to be used and has a chlorine concentration of 150 ppm or less. In addition, the colloidal silica to be used has a chlorine concentration of 500 ppm or less, and the colloidal silica is produced using at least any one acid of sulfuric acid, phosphoric acid, and organic acid.

Provided is a porous honeycomb filter comprising a porous first cell wall that permits exhaust gas to permeate, a second cell wall that permits exhaust gas to permeate than the first cell wall, and a cell that is surrounded by the first cell wall and the second cell wall to form an extending gas flow passage. The second cell wall has a smaller porosity than the first cell wall.

Provided is a porous honeycomb filter comprising a porous first cell wall that permits exhaust gas to permeate, a second cell wall that permits exhaust gas to permeate than the first cell wall, and a cell that is surrounded by the first cell wall and the second cell wall to form an extending gas flow passage. The second cell wall has a smaller porosity than the first cell wall.

A honeycomb structure includes honeycomb segments, bonding layers and a circumferential wall. The bonding layers include bottomed-hollow voids which extend toward an internal side in an axial direction from an end face of the honeycomb structure and which are formed at at least one of intersections, and a ratio of a depth of each void in the axial direction to a length of each honeycomb segment in the axial direction is 5% or more.