Washout attempt

The washout test is a test method in building materials science and is used to determine the content of components that can be washed off in aggregates for mortar or concrete . Components that can be blown down consist of rock flour as well as clayey and silty components with a grain size <0.063 mm. Their content can not be determined with sufficient accuracy using a conventional sieve analysis .

Experiment description

Two equally heavy and moist samples are used for the experiment. One of the two samples is dried at 105 ° C. and the dry mass is then determined. The other sample is stored under water for 4 hours and then washed through the 8 mm, 1 mm and 0.063 mm test sieves. The experiment continues until the water passing through is completely clear. To determine the content of components that can be blown down, the residues of the sieves are dried and then added to the dry matter . The salary can be calculated using the following formula: ${\displaystyle m_{1}}$ ${\displaystyle m_{2}}$

${\displaystyle m_{a}={\frac {m_{1}-m_{2}}{m_{1}}}\cdot 100~\%}$

${\displaystyle m_{a}\quad }$	= Content of drainable components in%
${\displaystyle m_{1}\quad }$	= Dry matter sample without washing out in g
${\displaystyle m_{2}\quad }$	= Dry matter sample with washout in g

Norms and standards

• DIN 4226 - aggregates for concrete and mortar

Individual evidence

1. ↑ K. Wesche, P. Schubert: Building materials for load-bearing components . Gabler Wissenschaftsverlage, Wiesbaden 1993, ISBN 3-7625-2681-8 , p. 122 .