Volume 38, Issue 5 (September 2010)
On the Evaluation of Setting Time of Cement Paste Based on ASTM C403 Penetration Resistance Test
The standard setting test for setting of cement paste, ASTM C191, uses a very stiff dough with a low water content and does not give information about the gradual microstructural development over time due to hydration; but the standard test for concrete, ASTM C403, can be used on cement paste, is not limited to paste with low water content, and does give information about microstructural development. In this study, the C403 test procedure was modified to provide more reproducible data for cement paste, with the most important modification being to not remove bleed water. Since the purpose of ASTM C403 is to measure time of setting of mortar extracted from concrete, the values of penetration resistance in paste that correspond to initial and final set in concrete were determined: These values were 2 MPa for initial set and 14 MPa for final set.