Monitoring of External Prestressing Tendons Construction Process of Jiamusi Highway Prestressed Concrete Bridge during Strengthening in China

Abstract:

Jiamusi highway prestressed concrete bridge is located in the Jiamusi City within Heilongjiang province in the east north of China. The strengthening and repairing of the bridge structure can be provided an effective and economic solution in appropriate situation. The objective of this study are to monitor the construction process of external prestressing tendons for strengthening of Jiamusi highway prestressed concrete bridge. Monitoring process includes measurement of external prestressing tendons natural frequency, monitoring of tensile forces values of external prestressing tendons, monitoring of development of anchor beams cracks, and monitoring of anchor beam deformation. The results of monitoring process show that the box girder No. 11 has the largest values of proportional coefficient (K) and the maximum value is 327.8. Box girder No. 8 has the largest values of frequency, the maximum value is 3.499. Five levels of tension are used in the application of tensile force in the tension process of external prestressing tendons. These levels are level 1=248.2kN, level 2=496.4kN, level 3=744.6kN, level 4=992.8kN, and level 5=1241kN. The measured tendons elongation values of left box girder No.8 are more than the theoretical values. For left and right box girder No. 9, side external tendons of left box No. 10, and left and right box girder No. 11, the measured values are less than theoretical values of elongation. After tension process, there are no new cracks in the top, web, and bottom of anchor beam and a small number of cracks developed slightly. These cracks are found around ducts of external tendons. The length of cracks rang from 0.03m to 0.5m and width rang from 0.05 mm and 0.25mm. The longitudinal deformation of the interface and top of anchor beam is very small, ranging from 0.001mm to0.115mm, which averaged 0.026mm. The overall state of anchor beams and box girders during strengthening is good.

• Periodical: Advanced Materials Research (Volumes 163-167)
• Pages: 2873-2879
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.163-167.2873
• Online since: December 2010
• Authors: Ali Fadhil Naser, Zong Lin Wang
• Keywords: Crack, Deformation, Elongation, External Tendon, Jiamusi Bridge, Monitoring, Tensile Force

References

[1] E. Naser, Repair and Strengthening of Reinforced Concrete Structure, R. V. Anderson Associated Limited, Toronto, Canada, (2005).

[2] H.N. Arthur, Design of Pre-Stressed Concrete, John Wiley, New York, (1987).

[3] A. Thiru, and H. Tim, Strengthening of bridge headstocks with external post-tensioning: design issues and strengthening techniques, Road System and Engineering Technology Forum, pp.1-9, Queensland, Toowoomba, (2005).

[4] E. Ahmed, and Y. Sherif, Use of external pre-stressing to improve load capacity of continuous composite steel girders, Structure Congress, Structural Engineering and Public safety, ASCE, USA, (2006).

DOI: 10.1061/40889(201)156

[5] G. Ivanyi, and W. Buschmeger, Strengthening bridge superstructure due to external pre-stressing: experience in design and construction, FIP Symposium on Post-Tensioned concrete Structure, Symposium Papers, London, pp.384-397, (1996).

[6] T. Suntharavadivel, and A. Thiru, Overview of external post-tensioning in bridges, Southern Engineering Conference, pp.1-10, Toowoomba, (2005).