EXPERIMENTAL STUDY ON INFLUENCING FACTORS ON PSEUDO STRAIN HARDENING BEHAVIOR OF HIGH PERFORMANCE FIBER REINFORCED CEMENTITIOUS COMPOSITE

The practical application of fiber-reinforced concrete (FRC) in structural components has gained growing interest due to structural advantages such as improved tensile strength, distributed load transfer, crack width control, as well as superior durability. To this end, reliable structural assessment techniques and analytical models have been developed, placing emphasis on tension-softening behavior owing to the bond and pull-out mechanisms of fibers at a local crack. However, these models could not be directly applicable to evaluate the multiple cracking mechanisms of high-performance fiber-reinforced concrete (HPFRC), which exhibits strain-hardening behavior. To overcome this challenge, this paper presents a probabilistic analytical technique. This approach has employed the simplified diverse embedment model (SDEM). Then, an HPFRC member was modeled with multiple segments considering the most probable number of cracks. It was assumed that material properties had a normal probability distribution and were randomly assigned to each segment. To have reliable results, 10,000 analyses were performed for each analysis case and validated using experimental test data. Based on the analysis results, the actual strain-hardening tensile behavior of an HPFRC member could be reasonably predicted with the number of segments chosen on the basis of the fiber length.

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The Apparent Density, Tensile Properties and Drying Shrinkage of Ultra High Toughness Cementitious Composites

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.261-263.223 ◽

2011 ◽

Vol 261-263 ◽

pp. 223-227 ◽

Cited By ~ 6

Author(s):

Xiang Rong Cai ◽

Bai Quan Fu ◽

Shi Lang Xu

Keyword(s):

Strain Hardening ◽

Apparent Density ◽

High Performance ◽

Drying Shrinkage ◽

Uniaxial Tensile ◽

Cementitious Composites ◽

Fiber Reinforced ◽

High Toughness ◽

High Performance Fiber ◽

Pseudo Strain Hardening

A new class of high performance fiber reinforced cementitious composites called Ultra High Toughness Cementitious Composites (UHTCC) is developed in the last few years. It is a pseudo strain hardening material with maximum tensile strain capacity more than 3%, yet the fiber volume fraction no more than 2%. The multiple cracking patterns accompanying pseudo strain hardening behavior are obtained which implies high ductility, energy absorption capacity, and toughness. A remarkable characteristic distinguish it from conventional high performance fiber reinforced concrete is the maximum crack width of multiple cracks which is about 60µm under ultimate tensile load. Such micro-cracks are often small enough to prevent the intrusion of aggressive agents. From a durability point of view this composite can be considered as an effectively uncracked material. The performances of this new material, including the apparent density, the uniaxial tensile property, and the drying shrinkage performance, are experimental studied in this paper.

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MECHANICAL PROPERTIES OF A PVA FIBER REINFORCED ENGINEERED CEMENTITIOUS COMPOSITE

Proceedings of International Structural Engineering and Construction ◽

10.14455/isec.res.2014.40 ◽

2014 ◽

Vol 1 (1) ◽

Cited By ~ 1

Author(s):

Ting Huang ◽

Y.X. Zhang

Keyword(s):

Grain Size ◽

Strain Hardening ◽

Tensile Strain ◽

Construction Materials ◽

Cementitious Composite ◽

Fiber Reinforced ◽

Engineered Cementitious Composite ◽

Hardening Behavior ◽

Dog Bone ◽

Strain Hardening Behavior

High Performance Fiber Reinforced Cementitious Composites (HPFRCCs) are promising construction materials characterized by tensile strain hardening behavior. Engineered Cementitious Composite (ECC) is a special type of HPFRCC developed with enhanced ductility and durability. Coarse aggregates are usually excluded from the ECC matrix, and the reported ECCs are typically produced with microsilica sand having a maximum grain size of 200 µm. In this paper, a PVA-ECC mixture containing local dune sand with a maximum grain size of 300 µm was developed, and its compressive and tensile properties were experimentally investigated. A dog-bone-shaped specimen and a rectangular-coupon-shaped specimen were both used in the tensile test, and it was found after extensive research that the dog-bone specimen was more suitable than the rectangular coupon specimen. The experimental results from the dog-bone specimens indicated that the newly-developed composite possessed good tensile strain-hardening behavior, with a high ultimate tensile strength, and the compressive strength was comparable to that of existing PVA-ECCs.

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