3.5. Surface leaching and mass loss
In the case of H2SO4, physical observations revealed that a negative
volume change was entertained in the concrete matrix
through slight facial leaching. In fact, close inspections on specimens
particularly at the end of the 84 days curing period discloses
minute leaching of the cement paste, gradual disintegration of fine
aggregate particles and exposure of some coarse aggregate particles.
This indeed correlates previous report where the action of
acids on Portland cements was observed to cause leaching of calcium
hydroxide from the cement paste [27].