BS 12846-1:2011 pdf download – Bitumen and bituminous binders — Determination of efflux time by the efflux viscometer Part 1 : Bituminous emulsions
5 Reagents and materials
5.1 Light mineral oil. Light mineral oil having a viscosity equal or lower than 7 mm 2 /s at 40 °C.
5.2 Solution Sa. Aqueous solution with a 1 % mass of sodium lauryl sulfate preferably, or aqueous solution with a nominal 1 % mass of sodium oleate shall be used for testing anionic emulsions. Those solutions (surfactants) shall be solubilised with 1 % mass of sodium hydroxide (NaOH). The actual soap solution may be used if available on site, in case of routine tests or for simplicity.
NOTE S a stands for “anionic solution” as this solution is used for testing anionic emulsions.
5.3 Solution S c . Aqueous solution with a 1 % mass of alkyltrimethylammonium chloride preferably, or aqueous solution with a nominal 1 % mass of cetyltrimethylammonium bromide shall be used for testing cationic emulsions. Those surfactants shall be solubilised with 1 % mass of hydrochloric acid (HCl) (HCl concentration shall be approximately equal to 1 mol/l). The actual aqueous phase may be used if available on site, in case of routine tests or for simplicity. NOTE 1 S C stands for “cationic solution” as this solution is used for testing cationic emulsions.
NOTE 2 The solution of 1 % of cetyltrimethylammonium bromide should be prepared slightly above 25 ºC (but not higher than 30 ºC). Then it should be stored at a temperature of (25±1) ºC before test.
6 Apparatus Usual laboratory apparatus and glassware, together with the following:
6.1 Efflux viscometer (see an example of viscometer on Figure 1) consisting essentially of a cup with an orifice in the centre of the base which may be closed by a ball-and-socket valve (see Figure 2). Three forms are required, differing only in the size of the orifice (10 mm, 4 mm and 2 mm). For other dimensions of the cup and the ball-valve, see Figure 3.
The cup cylinder shall be made of brass. The ball valve should be made of corrosion-resistant metal, with a ball on a rod, a levelling peg attached to the rod and a hemispherical top by means of which the valve may be supported in a vertical position. The viscometer cups shall be equipped with suitable corks or caps for closing the orifices with the ball valve in position, and some means of covering the cups (e.g. lids) to prevent evaporation of water and minimize surface cooling effects. The viscometer-cup holder shall be capable of: supporting one or more cups in a vertical position; providing a valve support to hold the valve at least 16 mm vertically above the orifice of the cup during efflux of the test material.
NOTE 1 To enhance resistance to wear and corrosion of the ball and socket valve, the bottom of the cup may be made from a different, corrosion resistant, material and screwed to the brass tube. It is then advised to use the same material, such as for instance phosphor-bronze, for the cup bottom and the ball valve. Wrought nickel alloy with copper or metals NiCu30 in accordance with ISO 9722 are possible materials for the rod of the ball valve
NOTE 2 The viscometer cup should be provided with a lid suitable for closing the upper end of the cup without touching the test material when the cup is filled. This lid is provided with a central hole through which the thermometer can pass and with a groove on one side through which the rod of the valve can pass.
6.2 Viscometer water-bath, constant temperature for maintaining the test temperature to within ± 0,5 °C. A typical elevation and a plan of assembled viscometer are given in Figure 1.
6.3 Temperature controlled water bath, maintained at (40,0 ± 0,5) °C, in which one or more of the viscometer cups can be immersed up to the rim of the cup.
NOTE 1 Other test temperatures are (50,0 ± 0,5) °C or (25,0 ± 0,5) °C.