In Switzerland the employment of asphaltic plug joints (APJ) is regulated in the ASTRA guideline expansion joints made of polymer bitumen (edition 1998).
This ASTRA guideline for expansion joints made of polymer bitumen is valid until December 2003. That means that a revision work of this guideline will be started in the 2003.
The results of our research work serve as basis for the revision: Research work FA90/92 "Object observation and data acquisition" and AGB2001/083 "Characteristics of normalbroad and over-broad joints made of polymer bitumen after strong traffic load in Tessin (Viadotto delle Cantine)" as well as the experiences and the know-how of the Swiss Federal Laboratories for Materials Science and Technology with expansion joints made of polymer bitumen. In addition the data of old expansion joints made of polymer bitumen objects, in particular the ZEBRA objects, which were not integrated in both projects mentioned above, are naturally also for this revision very important.
Due to its importance in the context of the ZEBRA project expansion joints made of polymer bitumen samples (with asphalt) were already taken out of two objects (Obkirchen viaduct, A2 in Hergiswil NW and from the bridge Schulstrasse A11 in Opfikon ZH) and stored at the Swiss Federal Laboratories for Materials Science and Technology.
The investigations of the expansion joints made of polymer bitumen samples, that were already taken out and will be taken, and the important results from these investigations form the goal of this research project.
Determination of the behaviour of the asphaltic plug joints after long-term and strong influence by traffic and weather.
Following aspects will be evaluated:
- Firmness of the aggregates in the joints
- Adhesion behaviour between the joint and the adjacent pavement
- Firmness of the joint material
- Change of characteristic of the binder (polymer Bitumen)
1. Depth (ASTRA chapter 2.2.6.): Penetration by heavy traffic loads
2. Adhesion test at -20 ° C (ASTRA chapter 3.2.): Adhesion behavior between depression filling and covering
3. Splitting tensile strength at -20 °C (ASTRA chapter 2.2.5.): Strength of the depression filling
4. Split / impregnating ratio (ASTRA chapter 2.2.5.): Composition of the depression filling
5. Grain size distribution and visual assessment (ASTRA chapter 126.96.36.199 and 188.8.131.52.): Assess the state of rocks by heavy traffic loads
6. Gel permeation chromatography (ASTRA chapter 184.108.40.206.): Assess the state of the polymers.
7. Elastic recovery at 0 °C (ASTRA chapter 220.127.116.11.): To determine the elastic properties after a harsh drive.
8. Dynamic characteristic (ASTRA chapter 18.104.22.168.): Determine the dynamic characteristics after a harsh drive.
Suggestions on the improvement of the current requirements in the ASTRA guideline (edition 1998) by their next Revision.