Bonded honeycomb segment assembly

A bonded honeycomb segment assembly comprising:

• a plurality of honeycomb segments each including a cell structure having a plurality of cells as fluid passages partitioned by porous partition walls and provided in parallel with one another, and an outer wall provided in the outer periphery of the cell structure,
• wherein the outer wall of each of the plurality of honeycomb segments is bonded to one another via bonding layers, and
• a compressive Young's modulus M1 in the thickness direction of the bonding layers positioned in the vicinity of a center of gravity n a cross section of the bonded honeycomb segment assembly perpendicular to the fluid passage direction of the cells, and a compressive Young's modulus M2 in the thickness direction of the bonding layers bonding the outer wall of each of the plurality of honeycomb segments positioned in the outermost periphery of the bonded honeycomb segment assembly satisfy a relation of M1<M2,
• wherein the compressive Young's Modulus M2 is at least 20 MPa and not more than 40 MPa.