Hi Ahmad,

The word shrinkage on the graph is the clue. Shrinkage means contraction.  It appears the vertical axis of the bottom diagram is incorrectly labeled. 

Mr. Yasseri...I respectfully disagree.  The bottom graph is correctly labeled.  The upper graph is incorrect.  Standard PCC does not expand, even during curing.  It continues to shrink once initial set takes place.  Shrinkage compensating cement may cause some minor expansion during curing, but then acts similarly to PCC for the long term.  It is its initial expansion that overcomes the normal shrinkage expected with PCC.

Dear All,

I agree with Eng. Ronald that is the lower graph is the correct one ( see attached page for the same graph from other reference ), but I disagree with him in another point, he said "concrete continues to shrink once initial set takes place" actually concrete specimen swells as long as it is wet ( under water or sealed) and starts to shrink when it losses the water (drying), and it swells again after shrinkage if it is wetted.        (see attachment).

So, how can we inform ACI with this typing mistake? I tried to email them with no response. any suggestions ?