Self healing of high strength concrete after deterioration by freeze thaw

Some experiments have been performed to investigate the self healing of concretes deteriorated by internal cracking in the ASTM C666 procedure A rapid freeze/thaw test. Six different well cured concretes were deteriorated to various degrees. Then the specimens (concrete beams) were stored in water for 2-3 months. Resonance frequency, weight, volume and compressive strength were measured during deterioration and selfhealing. Concretes that lost as much as 50% of their initial relative dynamic modulus during freeze/thaw could recover almost completely during subsequent storage in water, somewhat varying with concrete composition and degree of deterioration. Compressive strength showed reductions of 22-29% on deterioration, but only 4-5% recovery on selfhealing. Freeze/thaw tests on deteriorated and self-healed specimens in partly sealed condition showed clearly that the deterioration was governed by the ability to take up water; the more water that leaked through the plastic foil during freeze/thaw, the larger the deterioration. Self healing may be an important factor giving concrete better frost durability in field than when submitting specimens to freeze/thaw cycles in water.