ISO 13473-5:2009 表面プロファイルを使用した舗装テクスチャの特性評価—パート5：メガテクスチャの決定 | ページ 6

3.1.1

舗装のテクスチャ

テクスチャー

テクスチャの波長が 0.5 m 未満の、真の平面からの舗装表面の偏差。

注記 1: 3.2 に従って、マイクロテクスチャ、マクロテクスチャ、メガテクスチャに分類されます。

[出典: ISO 13473-2:2002]

3.1.2

表面プロファイル

テクスチャ プロファイル

針の先端やレーザースポットなどのセンサーが、舗装面の線に沿って移動している間に、舗装面に継続的に接触または照射した場合に生成される舗装面の 2 次元サンプル。

注記 1:表面の輪郭は 2 つの座標によって記述されます。1 つは「距離」(横座標) と呼ばれる表面平面内の座標であり、もう 1 つは「垂直変位」と呼ばれる表面平面に垂直な方向の座標です (横座標)縦座標）。例を図 1 に示します。距離は、舗装の移動方向に対して縦方向または横方向 (横断) 方向、またはこれらの間の任意の方向である場合があります。

注記 2: ISO 13473-2:2002 から適応。

注記 3:テクスチャ プロファイルは表面プロファイルに似ていますが、テクスチャ範囲に限定されます。

3.1.3

プロフィルメーター

舗装面の形状を測定する装置

注記 1:舗装工学で使用されるプロフィロメータの現在の設計には、レーザー、光セクショニング、ニードル トレーサー、および超音波技術に基づくセンサーが含まれますが、これらに限定されません。

[出典: ISO 13473-2:2002]

注記2プロフィロメータの仕様はISO 13473-3で扱われています。

3.2.1

microtexture

pavement microtexture

deviation of a pavement surface from a true planar surface with the characteristic dimensions along the surface of less than 0,5 mm, corresponding to texture wavelengths up to 0,5 mm expressed as one-third-octave centre wavelengths

Note 1 to entry: Peak-to-peak amplitudes normally vary in the range 0,001 mm to 0,5 mm. This type of texture is the texture which makes the surface feel more or less harsh but which is usually too small to be observed by the eye. It is produced by the surface properties (sharpness and harshness) of the individual chippings or other particles of the surface which come in direct contact with the tyres.

Note 2 to entry: Figure 2 illustrates the different texture ranges, with approximate limits regarding their effects on vehicle-pavement interactions.

[SOURCE: ISO 13473-2:2002

3.2.2

macrotexture

pavement macrotexture

deviation of a pavement surface from a true planar surface with the characteristic dimensions along the surface of 0,5 mm to 50 mm, corresponding to texture wavelengths with one-third-octave bands including the range 0,63 mm to 50 mm of centre wavelengths

Note 1 to entry: Peak-to-peak amplitudes may normally vary in the range 0,1 mm to 20 mm. This type of texture is the texture which has wavelengths of the same order of size as tyre tread elements in the tyre/road interface. Surfaces are normally designed with a sufficient macrotexture to obtain a suitable water drainage in the tyre/road interface. The macrotexture is obtained by suitable proportioning of the aggregate and mortar of the mix or by surface finishing techniques.

Note 2 to entry: Based on physical relations between texture and friction/noise, etc., the World Road Association (PIARC), originally defined the ranges of micro-, macro- and megatexture (Reference [9]). Figure 2, which is a modified version of the original PIARC figure, illustrates how these definitions cover certain ranges of surface texture wavelength and spatial frequency. Note that ride discomfort includes effects experienced in and on motorized road vehicles and bicycles, as well as wheelchairs and other vehicles used by disabled people.

Note 3 to entry: Adapted from ISO 13473-2:2002.

3.2.3

megatexture

pavement megatexture

deviation of a pavement surface from a true planar surface with the characteristic dimensions along the surface of 50 mm to 500 mm, corresponding to texture wavelengths with one-third-octave bands including the range 63 mm to 500 mm of centre wavelengths

[SOURCE: ISO 13473-2:2002]

Note 1 to entry: Peak-to-peak amplitudes normally vary in the range 0,1 mm to 50 mm. This type of texture is composed of wavelengths with the same order of size as a typical tyre/road interface and is often created by potholes or ripples in the surface. It is usually an unwanted characteristic resulting from defects in the surface. Surface roughness with longer wavelengths than megatexture is referred to as unevenness and typically takes the form of undulations in the surface.

3.2.4

unevenness

pavement unevenness

deviation of a pavement surface from a true planar surface with the characteristic dimensions along the surface of 0,5 m to 50 m, corresponding to wavelengths with one-third-octave bands including the range 0,63 m to 50 m of centre wavelengths

Note 1 to entry: Pavement characteristics at wavelengths longer than 0,5 m are considered to be above that of texture and are referred to here as “unevenness”. For airfield applications, even wavelengths longer than 50 m would be considered.

[SOURCE: ISO 13473-2:2002]

Note 2 to entry: Longitudinal unevenness is a type of surface roughness which, through vibrations, affects ride comfort in, and road holding of, vehicles. Transverse unevenness, e.g. due to the presence of ruts, affects safety through lateral instability and water accumulation. It is not the intention of this part of ISO 13473 to include terms which are specifically related to unevenness. Such terms are defined in ISO 8608 ^[1] , ISO 16063-1 ^[3] , ASTM E 950-98 ^[4] , and EN 13036-5 ^[6] .

3.3.1

profilometer method

method in which the profile of a pavement surface is measured and the data used for calculation of certain mathematically defined measures

Note 1 to entry: In most cases, the profile is recorded for subsequent analysis, in some cases it may be used only in real-time calculations.

[SOURCE: ISO 13473-2:2002]

3.4.1

texture spectrum

spectrum obtained when a profile curve has been analysed by either digital or analog filtering techniques in order to determine the magnitude of its spectral components at different texture wavelengths (see 3.4.2) or spatial frequencies (see 3.4.3)

Note 1 to entry: A texture spectrum presents the magnitude of each spectral component as a function of either texture wavelength or spatial frequency.

Note 2 to entry: Adapted from ISO 13473-2:2002.

3.4.2

texture wavelength

λ

quantity describing the horizontal dimension of the irregularities of a texture profile

[SOURCE: ISO 13473-2:2002]

Note 1 to entry: Texture wavelength is normally expressed in metres or millimetres.

Note 2 to entry: Wavelength is a concept commonly used and accepted in electrotechnical and signal-processing vocabularies. Since many users of this part of ISO 13473 may not be accustomed to using the term wavelength in pavement applications, and because electrical signals are often used in the analyses of road surface profiles, there is the possibility of confusion. Hence the expression 'texture wavelength' is preferred here to make a clear distinction in relation to other applications.

Note 3 to entry: The profile may be considered as a stationary, random function of the distance along the surface. By means of a Fourier analysis, such a function may be mathematically represented as an infinite series of sinusoidal components of various frequencies (and wavelengths), each having a given amplitude and initial phase. For typical and continuous surface profiles, a profile analysed by its Fourier components contains a continuous distribution of wavelengths. The texture wavelength in ISO 13473 (all parts) is the reciprocal of the spatial frequency, the unit of which is reciprocal metre, equivalent to cycles per metre. See also 3.4.3.

Note 4 to entry: The wavelengths may be represented physically as the various lengths of periodically repeated parts of the profile; see Figure 1.

3.4.3

spatial frequency

f _sp

inverse of texture wavelength (3.4.2)

Note 1 to entry: Spatial frequency is normally expressed in reciprocal metres, see also 3.4.2, Note 3.

Note 2 to entry: The term “frequency” used in the time domain (more precisely “temporal frequency”), corresponds to “spatial frequency” in the space domain.

Note 3 to entry: Adapted from ISO 13473-2:2002.

3.5.1

texture profile level

L _{tx, λ}

L _{TX, λ}

logarithmic transformation of an amplitude representation of a profile curve, Z ( x ), the latter expressed as a root mean square value

Note 1 to entry: To distinguish between octave and one-third-octave bands, the subscript for L is written in capital letters when it relates to octave bands, L_TX,λ , and in lower case letters when it refers to one-third-octave bands, L_tx,λ .

Note 3 to entry: Octave-band and one-third-octave band filters are specified in ISO 13473-2:2002, 4.4.

Note 4 to entry: Texture amplitudes expressed as r.m.s. values, whether filtered or not, can have a range of several magnitudes; typically 10^-5 m to 10^-2 m. Spectral characterization of signals is used frequently in studies of acoustics, vibrations, and electrotechnical engineering. In all those fields it is most common to use logarithmic amplitude scales. The same approach is preferred in this part of ISO 13473.

Note 5 to entry: Texture profile levels in practical pavement engineering typically range from 20 dB to 80 dB with these definitions.

Note 6 to entry: Adapted from ISO 13473-2:2002.

3.5.2

megatexture level

L _Me

special case of texture profile level with the profile passing through a bandpass filter encompassing all one-third-octave bands within the megatexture range according to 3.2.3

[SOURCE: ISO 13473-2:2002]

3.6.1

evaluation length

l

length of a sample from a profile which has been or is to be analysed

Note 1 to entry: Evaluation length is normally expressed in metres or millimetres.

[SOURCE: ISO 13473-2:2002]