Ash on the TLA can affect the level of modified asphalt of the study

Abstract: The Trinidad Lake Asphalt (TLA) contains about 35% ~ 37% of the mineral fine particles (ash). As ash density than pure asphalt density, TLA modified asphalt products in the storage and transportation process is easy to produce ash segregation, leading to the use of performance degradation. Therefore, this paper combined with Foshan - Rapid Link Ring TLA Modified Asphalt Pavement around the ash content of 40% TLA modified asphalt performance of a systematic theoretical analysis and laboratory tests, which made the control targets ash and construction proposals.

Keywords: TLA modified asphalt; asphalt mixture; ash; performance

According to the Research analysis, TLA contains approximately 53% to 55% bitumen, 35% ~ 37% of the mineral fine particles (ash), 9% to 10% of the minerals, synthetic organic and volatile substances in the water. TLA The ash is very small, all less than 2.36 mm, of which 90% is less than 0.075 mm, 44% less than 0.01 mm. the ash density than pure asphalt (TLA modified asphalt that is removed the remaining part of the ash) of the density, therefore, the TLA is easy to produce modified asphalt segregation of ash deposition. has experience and Research show that: with storage time and transportation time, means that the increase in ash deposition time, TLA modified asphalt will be more ash segregation significantly, resulting in mixing plant used TLA modified asphalt performance degradation, seriously affecting the TLA modified asphalt concrete pavement construction quality. Therefore, this combination of Foshan - Rapid Link Ring asphalt pavement Engineering, analysis of ash in asphalt TLA TLA modified on high and low temperature performance of asphalt, asphalt to guide the construction process control TLA.

A different preparation of modified bitumen ash TLA
Since in practice will be isolation of ash and pure asphalt is too much trouble, so this Research take a more direct, is closest to the actual situation of the scene ash prepared TLA different modified asphalt, modified asphalt will be finished TLA into the container, and then Place in oven temperature, making the ash natural sedimentation. According to the test of the need to select different slice thickness and deposition time will remove the direct slicing TLA modified asphalt, respectively, modified asphalt layers TLA Stir to get a different ash TLA modified asphalt content. Specific steps are as follows [1]:
(1) Prepare a volume of 30 000 mL cylindrical aluminum container lids, container diameter 30 cm, height 45 cm, to wash and dry.

(2) Preparation of TLA in the modified asphalt test chamber, and injected into the container. Will be filled with TLA modified asphalt products placed in the oven, place the time will be longer taken into account, in order to prevent the asphalt aging, will get 130 constant temperature �� + -5 ��.

(3) to place the time, the asphalt layer with a spoon to scoop into the test cups, respectively, the resultant ash content of different TLA modified asphalt.

(4), respectively, scoop out the layer of asphalt on each trial even mixing cup to cup as a unit test ash content were determined, and the TLA parts of modified asphalt performance tests.

TLA 2 different ash content of the technical nature of modified asphalt
Were prepared by the above method were 10.80% ash, 11.98%, 13.38%, 14.35%, 15.50%, 16.49%, 17.42%, 18.29%, 19.76% of the TLA modified asphalt, then TLA ash content of different reform The three indicators of asphalt test, ash content test, the viscosity experiment, the ash content of the TLA Modified Asphalt Performance. test results shown in Table 1, TLA modified asphalt with the ash content in Figure 1.

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As the ash content increases, the measured softening point rising, the overall increasing trend is linear, and the ash content increased by 1%, the average increase of 0.7 ��. Different ash content of the TLA modified asphalt softening point and the equivalent of the measured softening T800 has a good point change in the law of consistency, and the overall ash content of the TLA the same measured softening point of modified asphalt softening point than the average equivalent of about 1 �� higher, indicating the presence of wax base asphalt softening point will appear High phenomena, with the T800 compared to the TR & B, the amendment is more appropriate. With the increase of ash content, the viscosity of asphalt 135 �� showed a linear trend also will be gradually increased, and the process can be divided into two stages : When the ash content increased by 1%, ash content 10.80% ~ 15.50%, the average increase of 0.05 Pa �� s; ash content 15.50% ~ 19.76%, the average increase of 0.08 Pa �� s. In summary, With the increase of ash content, through visual analysis of testing data shows that, TLA modified asphalt high temperature performance is improved, this is due to increased ash material in the pure TLA modified asphalt stiffness modulus of asphalt, and enhance high temperature deformation resistance of asphalt to improve high temperature performance of asphalt.

With the increase of ash content, TLA modified asphalt brittle point T1.2 equivalent overall at -3.1 �� ~ 2.4 �� in the range of changes, the change process can be divided into two parts: when the ash content 10.80% ~ 14.35% at the time , T1.2 about changes in the -3.0 ��; when the ash content of 14.35% ~ 19.76%, the ash content for each additional 1%, T1.2 average increase of 0.1 ��. At the same time, 25 �� Ductility in 36.5 cm ~ 93.1 cm in within the ash content increased with the sharp decline. In general, the ash content for each additional 1%, 25 �� extension of the average degree of reduction of 8 cm. experimental data show that the increase will reduce the ash content of modified asphalt at low temperature crack TLA index, and the impact on the ductility index was particularly notable.

Through the above analysis shows that, due to the impact of ash, TLA equivalent modified asphalt brittle point T1.2 (absolute value) and the generally low values ​​of ductility and the ductility test results of greater impact. In fact, in the ductility TLA modified asphalt test specimen found in Fracture vibration in large delay, large cracked beneath his feet to hear that great cohesion TLA modified asphalt, which affects the test results, so the ductility and equivalent brittle point T1. 2 (absolute value) does not reflect the low temperature crack resistance of asphalt TLA actual situation. This study suggests that, TLA low temperature crack resistance of modified asphalt mixture, through its performance evaluation.

3 Summary
TLA modified asphalt with the increase of ash content, TLA modified asphalt softening point, equivalent softening point and viscosity of 135 �� increased to varying degrees, 25 �� decrease of penetration, indicating that the increase of ash content to improve the TLA modified asphalt high temperature performance and resistance to deformation of the target.

25 �� ductility and T1.2 (absolute value) decreased with increasing ash content decreased, indicating the presence of ash will reduce the low-temperature asphalt TLA index. In fact, TLA is a natural asphalt, with good low-temperature performance. Therefore, this study suggests that low temperature performance of modified asphalt TLA and aging should be primarily through its asphalt mixtures to evaluate the performance test.

References:
[1] Huang Lei. TLA modified asphalt and ash on the Performance of Mixture [D]. [Changsha University of Science degree thesis]. Changsha: Changsha University of Highway Engineering, 2008.5.

[2] Chen Jinan. Trinidad Lake Asphalt and prospects [J]. Foreign Highway, 2000,20 (2): 28 ~ 31.

[3] Fengxin Jun, Hao Peiwen, check Xudong. TLA Modified Asphalt and Asphalt Mixture Performance [J]. Highway, 2007,5:161 ~ 165.

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