Binder extraction

Binder content is determined using one of the following methods (a) binder extraction method, (b) ignition method or (c) nuclear method. 

The binder extraction method is the most common and widely used method for determining the binder content in the mixture. It uses hydrocarbon solvents capable of dissolving bitumen and a binder extraction apparatus. Because of the high purchase and disposal costs of solvents, the risk to the operator s personal health and safety and the environmentally unfriendly nature of the hydrocarbon solvents, this test method was started to be replaced with the ignition method. The binder extraction method by European standards is conducted in accordance with CEN EN 12697-1 (2012), whereas that by American standards is in accordance with ASTM D 2172 (2011) or AASHTO T 164 (2013) and AASHTO T 319 (2008). A detailed description of the binder extraction test method is given in Section 9.6.1. 

METHODS FOR DETERMINATION OF BINDER CONTENT 9.6.1 Binder extraction methods... 

The determination of binder content of asphalts and reclaimed asphalts by the binder extraction method consists of the following steps ... 

Binder extraction with hot or cold solvent can be conducted with various devices, which characterise the binder extraction method used (hot extraction or cold extraction). 

As mentioned above, after the extraction of the binder, the aggregates are dried and sieved for aggregate gradation determination. With some, the binder extraction method is also capable of determining the possible water contained in the mix. Of course, the determination of water content (if any) can be carried out before the binder extraction procedure by weight loss, after heating the mix in an oven for 2 to 3 h at 150-160 C (until a constant mass is obtained). The above presupposes the fact that no further tests are going to be carried out on the extracted bitumen. 

It is noted that the residual mineral matter in the binder extract may also be determined by incineration (see Section 9.6.3). 

Determination of residual mineral matter in the binder extract by incineration... 

The incineration method for determining the residual matter in the binder extract is used by some extraction methods for residual binder content as an alternative method (see Figure 9.1). 

More information about the determination of residual matter in the binder extract by incineration is given in CEN EN 12697-1 (2012), Annex C. 

The binder extraction is carried out by washing the asphalt with solvent and filtering the solution, repeatedly in an extraction/filtration vessel. The extraction is carried out by rotating the vessel for 5 min at 30 rpm, while the vessel is positioned vertically (unlike the rotating bottle extraction method). The extraction vessel is equipped with three cloth sieves (2.00 cm, 300 mm and 75 mm). 

Binder properties consist of the determination of penetration, the softening point or the viscosity of the binder extracted from the RA. 

Binder Extraction. We studied the removal of polymeric binder material with compressed gases such as CO2, propane and butane from a ceramic green product in its final shape before the sintering step. We have shown that a successful extraction is well possible without any dimensional change in the ceramic body [50]. The time necessary for such an extraction (about 30 min.) is only a fraction of the time needed usually for a controlled soft pyrolysis of the polymeric binders... 

The other main natural binder is protein that is prepared by extraction from soy meal (100). Casein [9000-71 -0] once a large-volume paper-coating binder, has markedly declined in use because of its high price and susceptibiHty to microbial attack. 

Asphalt (bitumen) also occurs in various oil sand (also called tar sand) deposits which occur widely scattered through the world (17) and the bitumen is available by means of various extraction technologies. A review of the properties and character of the bitumen (18) suggests that, when used as an asphaltic binder, the bitumen compares favorably with specification-grade petroleum asphalts and may have superior aging characteristics and produce more water-resistant paving mixtures than the typical petroleum asphalts. 

In addition to supplying transportation fuels and chemicals, products from coal liquefaction and extraction have been used m the past as pitches for binders and feedstocks for cokes [12]. Indeed, the majority of organic chemicals and carbonaceous materials prior to World War II were based on coal technologies. Unfortunately, this technology was supplanted when inexpensive petroleum became available dunng the 1940s. Nevertheless, despite a steady decline of coal use for non-combustion purposes over the past several decades, coal tars still remain an important commodity in North America. 

Solvated polymers are approaching "gels" in properties, depending on the mobility of the molecules. In some cases the action of a binder and of a separator are combined. By extraction of one of the components and refilling the voids with a liquid, a two-phase system can be created (Bellcore). There are irreversible and re-... 

Chromatographic procedures applied to the identification of proteinaceous paint binders tend to be rather detailed consisting of multiple analytical steps ranging from solvent extractions, chromatography clean up, hydrolysis, derivatisation reactions, and measurement to data analysis. Knowledge of the error introduced at each step is necessary to minimise cumulative uncertainty. Reliable results are consequently obtained when laboratory and field blanks are carefully characterised. Additionally, due to the small amounts of analyte and the high sensitivity of the analysis, the instrument itself must be routinely calibrated with amino acid standards along with measurements of certified reference proteins. All of these factors must be taken into account because many times there is only one chance to take the measurement. 

The chemical composition of birch bark tar is dependent on the temperature at which tar is produced. In producing simulated tars in the laboratory for comparison with an adhesive used to repair a Roman jar from Stan wick, Charters et al. (1993) found that tars prepared at 350 °C displayed an increase in triterpenoid hydrocarbons as well as unresolved components presumably resulting from pyrolysis, although the precise nature of these molecules has not been elucidated. Binder et al. (1990) and Charters et al. (1993) also report the presence of allobetul-2-ene [Structure 7.24] in aged birch bark tars. Since this molecule has not been reported in extracts from fresh birch bark, it could be formed during heating to produce the tar (Regert et al., 2003). 

Figure 7.2 shows a typical TLC plate. Some components are visible to the naked eye, but others may need to be visualized. Commonly this can be achieved under a UV light if the compounds themselves fluoresce, or if they alter the behavior of the fluorescent binder. It is also possible to spray the plate with dye or oxidize the compounds with sulfuric acid to make them visible, although the last method will result in the destruction of the sample. Once identified, areas of the stationary phase can be scraped from the inert plate and solvent extracted to yield the separated components for further analysis, if needed. 

From Equation 2.2, it can be seen that the viscosity of the slip plays an important role. It regulates the formation rate of the gel layer and helps to prevent the slip from penetrating the support pore system. In the colloidal suspension route the evolution of the viscosity during the solvent extraction is slow during the very first steps of the process and drastically increases just before gelling. With the polymeric gel route a more gradual increase of the viscosity is observed. In both cases the evolution of the viscosity can be modified by the addition of binders to the sol slip . Different kind of binders are chosen depending on the nature of the solvent, the compatibility with the precursors and the viscosity of the system. 

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