a reinforced-concrete structure whose stressed state results from the hardening of concrete prepared from self-stressing (expansive) cement. A distinctive feature of a self-stressed structure is that all reinforcements, regardless of location, become prestressed as the concrete expands. As a result of the intense self-compression during the self-stressing process, the concrete gains considerable strength (20 to 30 percent greater than concrete hardened in the free state, that is, without reinforcements), crack resistance, and imperviousness to water, gasoline, and gases.
Formulas applicable to ordinary prestressed concrete structures are used in the design of self-stressed structures. Self-stressing is suitable for almost any reinforced-concrete structure, but it is especially useful for pressure pipes, tanks, storage basins, surfaces for highways and airports, double-curved shells, tunnel linings, and hydraulic structures.
The erection of a self-stressed structure requires close attention to the hardening of the concrete, including a water curing for seven to ten days after the concrete attains a strength of 10 meganewtons/m2. Prefabricated, self-stressed reinforced-concrete structures are subjected to moist steam curing at the factory.
V. V. MIKHAILOV