Disclosed are compositions containing an Ulva extract and a concrete admixture suitable for inclusion in cement and concrete compositions, and methods of use thereof.

Porous ceramics that meet the demand for bone substitute materials and the like are provided. Solution is provided by porous ceramics and a method for producing the porous ceramics, which are ceramics having pores, the pores including open pores and closed pores, the open pores including a plurality of large-diameter open pores having a pore size within a range of 20 to 600 m and a plurality of micro-diameter open pores having a pore size within a range of 1.0 m or smaller, wherein the large-diameter open pores are distributed substantially uniformly all over the ceramics.