Prediction of standard compressive strength of cement by the electrical resistivity measurement

This study was undertaken to suggest a rapid testing method which would permit prediction of standard compressive strength of a cement within 24 h. Eight cement pastes were prepared with three strength grades of cements at a constant water–cement ratio of 0.4 for electrical resistivity measurement during first 24 h and eight mortars were prepared with the same cements as those used in the pastes according to the procedures in ISO679:1989 for standard compressive strength tests of cement at 28 d. The results from electrical resistivity measurement show that the higher electrical resistivity value of the pastes is reached when the higher strength cement is used. A linear relation is established between the standard compressive strength of cements at 28 d and the resistivity of the pastes at 24 h. It is possible that an accelerated and non-destructive method could be developed to estimate the standard compressive strength of cement based on a quantitative relationship with electrical resistivity at 24 h.

► Suggest an accelerated testing method for determining standard compressive strength of cement within 24 h.
► Adjust mix proportion of concrete and correct mix proportion of raw materials in cement factories.
► Make the quality of cement and concrete under control in time.