The relationship between electrical resistivity of cement paste and its restrained shrinkage crack with the aid of novel apparatus and ANSYS simulation
Cement paste hydration behavior and restrained shrinkage cracks were experimentally monitored using a non-contact electrical resistivity apparatus and a novel steel crack frame respectively. The electrical resistivity measurement indicates that all the curves followed similar trend and the lowest water cement ratio paste indicates highest resistivity values and reaches inflection point earliest. The restrained shrinkage crack test demonstrated that lower water cement ratio paste cracked earliest which therefore confirmed its highest crack tendency. The time upon which all the samples initiated cracks was not very long; hence the novel steel crack frame is proved effective and alternatively convenient method of ascertaining crack tendency of cement paste. A relationship has been developed between the highest inflection time of the tested samples and the corresponding crack time. Tensile strength test and ANSYS stress simulation were also performed; the results were plotted on one graph in which the intersection point of tensile strength and ANSYS stress of a particular sample predicts its crack time. The crack initiation ages obtained are consistent to the experimental results which indicate that ANSYS numerical analysis can also be utilised to predict the crack tendency of cement paste.