Large scale tensile tests of high performance fiber reinforced cement composites

Author(s): S-H. Chao, W-C. Liao, T. Wongtanakitcharoen, A.E. Naaman
Paper category: Workshop
Book title: Fifth International RILEM Workshop on High Performance Fiber Reinforced Cement Composites (HPFRCC5)
Editor(s): H.W. Reinhardt, A.E. Naaman
ISBN: 978-2-35158-046-2
Pages: 77 - 86
Total Pages: 10
Language: English

Abstract: 
The macro-scale properties of high performance fiber reinforced cement composites (HPFRCC) depend on their stress-strain characterization under tension; hence direct tensile tests are essential for determining the fundamental tensile behavior of HPFRC composites. Most tensile tests for obtaining the tensile response of FRC composites are carried out on relatively small-size specimens which do not account for more realistic fiber distribution and content variability in full scale structural applications. Moreover, they do not incorporate the tension stiffening effect due to the presence of continuous reinforcement in real structural concrete elements. In this study, long prismatic specimens of dimensions 64×76×3050mm reinforced with one unstressed prestressing steel tendon along their longitudinal axis were tested in tension under monotonic load. The tensile load was applied to the prestressing tendon and strains in the tendon (inside and outside the matrix) as well as in the FRC material along the specimen were recorded. The advantage of using a prestressing steel tendon is that a strain as high as 0.9% can be applied while the tendon remains linear elastic, thus allowing a stable environment for loading-unloading and for measurements of crack width and spacing. In this study, the stress-strain curves of HPFRC composites (here a self consolidating concrete mixture is used) obtained from long-prism tests were compared to curves obtained from small scale direct tensile tests of dog-bone shaped specimens without continuous reinforcement. It was observed that the onset of damage localization following peak stress is significantly delayed in the presence of continuous reinforcement. The strain capacity of an HPFRC composite was also considerably enhanced due to the presence of the reinforcing steel strand.

Online publication: 2014
Publication Type: full_text
Public price (Euros): 0.00