Can aggregate be successfully exposed in architectural concrete by acid washing?
Acid washing has been used successfully when it is applied to concrete that has already attained a strength of 4500 psi. The method has its limitations, however, especially on vertical surfaces which are difficult to etch uniformly because the downward acid flow over the surface is difficult to regulate and also because the surface may absorb the acid nonuniformly and consequently react nonuniformly with it. The method also creates more difficulties in protection of the personnel than does sandblasting and there is always the problem that some acid will run off the surface before being spent and do damage elsewhere.