【免费下载】道材第三章作业答案

for long-term aging：PAV（压力老化试验）Addition: After aging ,penetration decrease, viscosity increase, ductility decrease, softening point increase, mass may decrease or increase.

3. Show how various Superpave tests used to characterize the asphalt binder are related to pavement performance?

Solution：

(1)Aging test老化试验-------Durability

RTFOT ：for short-term aging

PAV：for long-term aging

(2) Rotary viscosimeter （旋转式粘度计）------- Viscosity

measure viscosity of asphalt

(3)Dynamic Shear Rheometer （动态剪切流变仪）-----Visco-elastic Determination of viscoelastic properties of asphalt within temperature at 5-85℃ before and after aging, and also presentation the ability for anti-rutting at high temperature condition

(4) Direct Tension Test（直接拉伸仪）-----Low temperature property Evaluation of asphalt material performances at low temperature, such as stress and strain when destruction, especially to evaluate the performances for polymer modified asphalt.

(5)Bending Beam Rheometer （弯曲梁流变仪）------Low temperature property

Measurement accurately of stiffness at low temperature and creep rate for

asphalt .

4. Briefly describe the test method of penetration, softening point and ductility.

Solution:

Penetration test（penetration）:

测定在规定温度和时间内，附加一定质量的标准针垂直灌入试样的深度。规范规定：标准针、针连杆和附加砝码的总质量为

,测试温度为25℃，标准针贯入时间为5s。

100

g

g1.0

Measured at a specified time and temperature, plus a vertical needle poured quality standard depth of the sample. Specification: Standard pin, connecting rod and the additional weight of the total mass of the test temperature is 25 ℃, the standard needle penetration time of 5s

Ring and ball test (softening point ):

环球法：将沥青试样装入规定尺寸的铜环内（内径18.9mm），试样上放置标准钢球（质量为3.5g）在水或甘油中，以规定的升温速度（5℃/min）加热，测定使沥青软化下垂至规定距离（垂度为25.4mm）时的温度，用℃表示。

the asphalt sample was placed in the predetermined size copper ring (inside diameter 18.9mm), the ball is placed on the standard sample (mass of 3.5g) in water or glycerol, in a predetermined heating rate (5 ℃ / min ) heating, softening determined that the distance to a predetermined temperature sag (sag is 25.4mm) when, with the said ℃.

Ductility test：

用延度仪测定，将沥青试样制成“∞”形标准试模（中间最小截面为1cm2），在规定速度（5℃/min±0.25℃/min）和温度（通常采用25℃、15℃、10℃或5℃）下拉伸至断时，测定其长度，以cm表示。规范规定：A、B级沥青采用10℃，C级采用15℃。

Ductility was measured with the sample is made of asphalt "∞" shape standard test mode (minimum cross-section of the middle 1cm2), at the prescribed speed (5 ℃ / min ± 0.25 ℃ / min) and temperature (usually 25 ℃,15℃, 10 ℃ or 5 ℃) stretched to breaking, measure the length in cm. Specification: A, B grade bitumen using 10 ℃, C class adopt 15 ℃.

5、What are the three colloid structure of asphalt, and what are their characteristics?

Solution:

①sol type:PI＜-2.More oil components and resin,thick external membrane of the micelle,free movement among micelles.

②gel type:PI＞+2.Better elasticity and viscosity. Lower temperature stability,mobility and plasticity.

③sol-gel type:-2

6、三组分：Oil、Resin、Asphaltene

四组分：Asphaltene、Saturated 、Aromatics、Resin