POLYMER-IMPREGNATED FIBER-REINFORCED MORTARS, CERAMIC-METAL SYSTEMS DIVISION SYMPOSIUM, NO. 10-CS-70, 
Journal of the American Ceramic Society, Vol 54, No. 3, by F. Flajsman, D.S. Cahn, and J.C. Phillips, March 1971, 2 pages.

Eight spherical models with outside diameters of 16 inches and wall thicknesses of 1 or 2 inches were fabricated of polymer-impregnated concrete (PIC) having a uniaxial compressive strength of 21,000 psi. The spherical specimens were tested under hydrostatic loading conditions of short-term, long-term, and cyclic pressure. The test results show that the PIC spheres respond to hydrostatic loading with linearly elastic behavior and that the implosion pressures are greater by approximately 400/o than those for similar regular-concrete spheres. Under short-term loading the specimens having a wall-thickness-to-outside-diameter ratio of 0.063 and 0. 125 (1- or 2-inch walls to 16-inch OD) implode at average hydrostatic pressures of 4,810 and 8,475 psi, respectively. Classical elastic theory predicts the strain behavior and implosion pressures of the PIC sphere within engineering accuracy.