Investigation of Concrete Segregation by Ultrasonic Pulse Velocity

Segregation is a separation of the constituents of a concrete mix or a fresh mortar, which can be caused by insufficient mixing, excessive vibration or major fluidity. In addition, water content is one of the fu ndamental parameters in the composition of concrete. Water quantity andquantity can influence the separation between mortar and gravels. Water-reducing admixtures are used to reduce the quantity of mixing water required to produce concrete of a certain slump. These admixtures (plasticizers, fluidizers, among others) are added to concrete to make high-slump flowing but are not free of excessive bleeding or segregation. 

On the other hand, in the case of highly cohesive concrete mixtures such as those containing limestone filler, even in the absence of external bleed water, static segregation can still take place and.The mixing method proposed by for SCC is based on equivalent mortars. The literature describes many tests to characterize the segregation, including the sieve segregation index test, cylinder test, column test, ball test, pale test, etc. Shindoh and Matsuoka have evaluated self-compacting concrete test methods.