Research on Long-Term Expansive Deformation of Steel Fiber Reinforced Expansive Concrete

Abstract:

The inherent low tensile strength and shrinkage result in cracking of concrete under work loads. A new way to improve cracking properties is distributing steel fibers into expansive concrete to form a type of composite which is called steel fiber reinforced expansive concrete. This type of high performance concrete could compensate shrinkage as well as improving crack strength. For this concrete, the key point to ensure high performance and safety of concrete structure is to keep a stable expansive deformation during long-term service. A series of tests were carried out to measure long-term restrained expansive deformations of steel fiber reinforced expansive concrete with ages under various restrictions like steel bars and steel fibers. The test investigated some 3-year specimens. For all specimens, test parameters included 2 ratios of steel bar reinforcement, 4 volume fractions of steel fiber and 4 dosages of expansion admixture. The test results showed that the expansion of concrete decreased with increasing of steel bar reinforcing ratio as well as steel fiber volume fraction. In addition, when being in a lower dosage of expansion admixture, the specimens presented remarkable retraction of the expansive deformation. However, when beyond a certain dosage of expansion admixture, the long-term expansive deformation had less change with ages and almost remained the same with 90-day deformation, namely less losses of deformation. Hence, for steel fiber reinforced expansive concrete, using an appropriate dosage of expansion admixture could meet the requirements of designed strengthening and compensating shrinkage.

• Periodical: Key Engineering Materials (Volumes 417-418)
• Pages: 945-948
• DOI: https://doi.org/10.4028/www.scientific.net/KEM.417-418.945
• Online since: October 2009
• Authors: Huan An He, You Gang Wang
• Keywords: Expansion, Long Term, Steel Fiber (SF)

References

[1] Qin Jie. Study on the Constrution Period、Running Period and Material-Change of Steel Lined Reinforced Concrete Penstock. Doctoral dissertation of Dalian University of Technology, (2002).

[2] Tian Wenling. Study on the Reinforcing Mechanism of Steel Fiber and Its application in Expansive Concrete. Doctoral dissertation of Dalian University of Technology, (1998).

[2] Wu Zhongwei, Zhang Hongzhi. Expansive Concrete. Beijing：China Railway Press，(1990).

[3] He Huannan, Huang Chengkui: Expansive Characteristics and Self-stress Value of Self-stressing Concrete Reinforced with Steel Bar and Steel Fiber, Journal of Building Materials, Vol. 7, No. 2, 2004，pp.156-160.

DOI: 10.4028/www.scientific.net/amr.168-170.1396

[3] .

[4] Idorn. GM. Expansive mechanisms in concrete. Cement and Concrete Research, 1992 (22): 1039～1046.

DOI: 10.1016/0008-8846(92)90034-s

[5] Sun Wei, Zhang Zhaozhou, Gao Jianming. Study on the performance of steel fiber reinforced expansive concrete. China Concrete and Cement Products, No. 5, 1994, pp.14-17.