Serious (aggregate)

A serious is a Granulat composed of a mixture of Sable and fine gravels. This one is used mainly in the execution of the pavements (roads and highways), of punts forms (parks of stationnnerment, surfaces of storage…), of tracks of aerodromes. In all these achievements, these are the decimetres thickness of low register which are used under the bitumen binder of couverture.
the low registers can be natural; reconstituted in power station; treated with the hydraulic binders (Cement, slag…) or with the Lime; or treated with the bitumen binders (Bitumen).

Denominations

The low registers are Granulat S whose granularity is of 0/D. type
Traditionnellement in France (begun again by standards NF) the typical granularities of the low registers are: 0/14 mm, 0/20 mm, 0/32 mm and 0/63 mm, even 0/80 Misters.

Serious untreated

The serious ones untreated (acronym GNT) are of 2 types, according to the way in which they are produced:

Serious natural - They are materials obtained in only one fraction, without mixture, water addition, as left the Crible of the career. In France, one qualifies them " low registers naturelles" , and in standard NF 98-129, of “GNT of the type has”. The new standard (IN 13285) does not differentiate them any more of the following ones.
Serious reconstituted humidified - They are materials obtained in at least 2 distinct granular fractions (for example a sand 0/4, with a fine gravel 4/10, and another 10/20, to form a sand-gravel mix 0/20), and, if need be, a water addition. Recombining and malaxation are made in a named special power station " power station of graves" , or " power station of blanc". In France, one qualifies them " reconstituted low registers humidifiées" (acronym GRH) and in null and void standard NF 98-129, of " GNT of the B" type;.

Treated low registers

They are materials obtained in the same way that the GRH to which one adds a binder.

Serious treated with the hydraulic binders - the binder can be a hydraulic Ciment, in this case one speaks about " serious-ciment" , or a road special binder, or a slag, or a dairy mixture - lime, or Ash flying-lime, even Pozzolana - lime. The content while binding is about 5%
Graves treated with the bitumen binders - the binder can be Bitume, it is a " serious-bitume". the addition of binder is done, either by a power station of GRH, the binder is then a emulsion water-bituminizes, or in a power station of recombining of the road coated (" power station of noir"), the binder is then a bitumen. The content of bitumen is about 4%.
Graves treated with the Chaux - Sometimes, except normalized process, of the low registers are treated with lime alone. They are often particular building sites, where one must make inert the clay traces contained in the low register. The reaction of lime with clay forms an effect of binder. The addition, from 2 to lime 5%, is done on the basis of preliminary test.

Characteristics

The geometrical, physical and chemical main features are those clean with the Granulat S. They are measured on a limited granular fraction (for example fraction 10/14 mm).

Moreover specifically, for the serious ones untreated, one seeks the maximum density (about 2,1 to 2,2 kg/dm ³), with optimum moisture: it is the optimum of modified Proctor (CPM).

One seeks also the best bearing pressure of the execution: by the index of immediate bearing pressure (IPI)

For the low registers treated with the hydraulic binders, one characterizes the tensile strength and the elastic module (Modulus Young).

Standards

NF P 98-129 of November 1994: " Serious not traitées" , replaced by the European standard INTO 13285 of May 2004: " Serious not traitées".
NF P 98-122 of November 1991: " special Serious-binder routier" , replaced by standard NF P 98-116 of February 2000: " Low registers treated with the binders hydrauliques".
NF P 98-115 of January 1992: Execution of the pavements.

Vocabulary

The serious term in this context comes from the Celte, of a radical grav (cf: gro in Welsh), which gave Latin engraved , at the time Gallo-Roman E.

In XII^ième century, serious was one of the forms regional of strike and meant gravel but also Plage and had a derivative gravel or gravel, in the direction of sand and beach.

The derivatives are:

gravel came to indicate (XVI^ième century) calculations of the urinary tracts.
rubble (1798), coming from engraved (1718), him even of gravois (1694), in the dictionaries of the French Academy and before of “gravoi” (XII^ième century).
gravel (XII^ième century), fine gravel (XVI^ième century) & gravel pit (XIX^ième century)
gravelly , in XIV^ième century means stony, it takes its medical direction in XVIième century and takes the direction of " licencieux" at the end of XVII^ième century.

The French regional of the North-East of the France still uses the words strike and grèvière , to indicate serious and gravel pit . The Lorraine Paul Verlaine, in his poême " Suns couchants" , for rimer with " rêves" , " sings; setting suns on the grèves". They are the beaches , the gravel pits not making dream the poêtes.

In English: " gravel " or " sand-gravel mix ". German
: " Kiessand "

External bonds

Coefficients of equivalence of bituminous materials with high module.
Standard structures of Roadways (CG92).

Beats-smg: Žvīrs

Random links: