Water susceptibility of fillers for bituminous mixtures

The water susceptibility of fillers for bituminous mixtures is determined by separation of the filler from the bitumen-filler mixture. The test is conducted according to CEN EN 1744-4 (2005). 

The bitumen and filler mixture, which contains 50 0.5 g of low-viscosity bitumen solution (50/70 bitumen and kerosene) and 10 0.1 g of filler passing through the 0.125 mm sieve, is stirred with hot water at 60°C 1°C for 300 5 s and left to rest for 300 5 s. The water is then emptied into a conical flask and stirred again for a further 300 5 s. 

The mixture at the end of 300 s is visually examined to determine any uncoated filler (separation is indicated by the turbidity of the water). If not, the filler is considered nonsus-ceptible to water. Otherwise, the water is collected and filtered to recover the filler. 

The susceptibility of filler to water (WJ is calculated from the following formula  

More details and information about the test are given in CEN EN 1744-4 (2005). 

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