A granular composite, comprising a disordered, flowable, powder of at least two groups of particles of different average volumes, where for at least two of the groups of particles, i) the average volume of the larger of two groups adjacent by average volume is no more than 10,000 times the average volume of the other group, ii) the dividing volume between at least two adjacent groups is a smallest minimum point in a passing curve of the composite, and where the value of the passing curve at the smallest minimum point between the two groups is no greater than 75% of the value of the passing curve at the largest maximum of either of the two groups, iii) the average number, per large particle, of contacts between particles from the larger of the two groups adjacent by average volume and other particles from the same group is greater than or equal to one, iv) no region of space that is contained entirely within the granular composite and is of height, width, and depth that are all at least in size on the order of several diameters of the largest particle of the larger of the two said groups is filled with only particles of either the smaller or larger groups, and further where in each region of such size, there are non-zero quantities of three particle arrangements consisting of one particle from the smaller of the groups and two particles from the larger of the groups such that the smaller particle and the two larger particles are part of the configuration that provides mechanical stability to the structure, as opposed to the smaller particle existing solely in the voids created between mechanically stable configurations of larger particles, and where the smaller particle is both in contact with and separating the two particles from the larger of the groups, v) a mixture of the two groups of particles in fixed amounts occupies a larger volume of space than a volume of space occupied by either of the two groups of particles on its own. i) the average volume of the larger of two groups adjacent by average volume is no more than 10,000 times the average volume of the other group, ii) the dividing volume between at least two adjacent groups is a smallest minimum point in a passing curve of the composite, and where the value of the passing curve at the smallest minimum point between the two groups is no greater than 75% of the value of the passing curve at the largest maximum of either of the two groups, iii) the average number, per large particle, of contacts between particles from the larger of the two groups adjacent by average volume and other particles from the same group is greater than or equal to one, iv) no region of space that is contained entirely within the granular composite and is of height, width, and depth that are all at least in size on the order of several diameters of the largest particle of the larger of the two said groups is filled with only particles of either the smaller or larger groups, and further where in each region of such size, there are non-zero quantities of three particle arrangements consisting of one particle from the smaller of the groups and two particles from the larger of the groups such that the smaller particle and the two larger particles are part of the configuration that provides mechanical stability to the structure, as opposed to the smaller particle existing solely in the voids created between mechanically stable configurations of larger particles, and where the smaller particle is both in contact with and separating the two particles from the larger of the groups, v) a mixture of the two groups of particles in fixed amounts occupies a larger volume of space than a volume of space occupied by either of the two groups of particles on its own.