Segregation evaluation of concrete pavements under excessive vibration using electrical resistivity measurement

Concrete pavements are typically constructed using slipform pavers. A vibration process is required to consolidate low workability concrete. However, improper vibration of fresh concrete can cause concrete pavement degradation, such as aggregate segregation and bleeding. This study evaluates the segregation of fresh concrete pavements under excessive vibration by measuring the electrical resistivity using the surface-contact electrode method. Various concrete mix proportions prepared with the recommended low slump values (25-75 mm) were consolidated using conventional and excessive vibrations controlled using a poker vibrator to cause the segregation including ingredient separation. The degree of segregation through the continuous vibration process was evaluated using the measured electrical resistivity and its decreased ratio. In addition, the occurrence of segregation was compared with the ratio of coarse aggregate settlement using the wet-sieving test. Under excessive vibration, the electrical resistivity of concrete having low slump values was decreased due to the rising of water without the settlement of coarse aggregate, but the concrete mixture having the highest workability shows that the coarse aggregate was settled about 160 % under excessive vibration with the decreased electrical resistivity about 15 %.