ABSTRACT
Other evidence(2,3,4,5) has shown that if the relative humidity in the atmosphere surrounding a concrete structure can be maintained at below 95%, ASR will be inhibited. However, the relative humidity of the surroundings is unlikely to be the same as the relative humidity in the pores of the concrete where the ASR takes place. Water in the pores of concrete maintained at a relative humidity of less that 100% is in a state of tension or suction. The pore water tension is balanced by compressive stress in the solid components of the concrete. The net effect is that any expansive stresses are counterbalanced, partly or completely, by the pore water tension or suction.
