• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.05b
• /
• pp.377-380
• /
• 2006

HPFRCCs(High performance fiber reinforced cementitious composites) is a class of FRCCs(Fiber reinforced cementitious composites) exhibit multiple crack. Multiple crack lead to improvement in ductility, toughness, and deformation capacity under compressive and tensile stress. These properties of HPFRCCs are affected by type of fiber, water cement ratio, type of admixture and rate of substitution. Furthermore these influence dispersion of fiber, mixing performance and fluidity of mixture. In this paper, HPFRCCs made of steel cord and carbon fiber were tested with water cement ratio, type of admixture and rate of substitution to evaluate characteristics of mixing and flexural strength.

• Proceedings of the Materials Research Society of Korea Conference
• /
• 1994.05a
• /
• pp.145-146
• /
• 1994

• Composites Research
• /
• v.23 no.3
• /
• pp.50-57
• /
• 2010

It is important to detect fibers in the sectional image of fiber reinforced cementitious composites (FRCC), since the fiber distribution is a crucial factor to predict or evaluate the mechanical performance of FRCC. In this paper, we investigated the fluorescence characteristics of Polyvinyl Alcohol (PVA) fibers, Polyethylene Terephthalate (PET) fibers, Polyethylene (PE) fibers, and Polypropylene (PP) fibers used in Engineered Cementitious Composites (ECC), which is a special kind of FRCC that incorporates synthetic fibers and exhibits extremely ductile behavior in uniaxial tension, to detect each fiber according to its type. Furthermore, optimum excitation and emission wavelengths were proposed on the basis of maximum difference of Relative Fluorescence Intensity (RFI) between two types of fibers used in the hybrid ECC. Optimum threshold values to discriminate two types of fibers using statistical tools were also proposed. Finally, images of four types of fibers obtained using a fluorescence microscope are compared.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2003.05a
• /
• pp.57-60
• /
• 2003

Generally, normal concrete has the disadvantages of low tensile strength, low ductility and volume instability. To improve its performance, fiber reinforced cimentitious composite(FRCC) have been development. These composites are composed of cement, sand, water, a small amount of admixtures, and an optimal amount of fiber like synthetic fiber and steel fiber. This research investigates influence of sand, hybrid fiber and fiber volume fraction, and reports the test results of mechanical properties, fracture behavior and failure pattern of the FRCC. Our experiment was observed that sand mixed FRCC has lower compressive strength and higher bending strength than no sand mixed FRCC, and more steel fiber mixed FRCC has higher compressive strength and bending strength. Hybrid FRCC of steel and polypropylene had superior properties than FRCC of polypropylene only in same fiber volume fraction.

• International Journal of Concrete Structures and Materials
• /
• v.6 no.3
• /
• pp.135-144
• /
• 2012

This article reviews the tailoring of engineered cementitious composites (ECC), a type of high performance fiber reinforced cementitious composites with a theoretical design basis, for special attributes or functions. The design basis, a set of analytic tools built on micromechanics, provides guidelines for tailoring of fiber, matrix, and fiber/matrix interfaces to attain tensile ductility in ECC. If conditions for controlled multiple cracking are disturbed by the need to introduce ingredients to attain a special attribute or function, micromechanics then serve as a systematic and rational means to efficiently recover composite tensile ductility. Three examples of ECCs with attributes of lightweight, high early strength, and self-healing functions, are used to illustrate these tailoring concepts. The fundamental approach, however, is broadly applicable to a wide variety of ECCs designed for targeted fresh and/or hardened characteristics required for specific applications.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2010.05a
• /
• pp.401-402
• /
• 2010

This research initially suggest flexural toughness density as a key parameter describing energy absorption capacity of High Performance Fiber Reinforced Cementitious Composites [HPFRCC] regardless of the size of specimen. Two types of high strength steel fibers, Hooked and Twisted fiber, were used in two types of flexural specimen ($100{\times}100{\times}350mm^3$ and $150{\times}150{\times}500mm^3$) to estimate and validate the flexural toughness density.

• Journal of the Korea institute for structural maintenance and inspection
• /
• v.22 no.3
• /
• pp.69-74
• /
• 2018

Fiber-Reinforced Cementitious Composites (FRCCs) have electrical conductivity by inserting reinforced conductive fibers into a cementitious matrix. Such characteristic allows us to utilize FRCCs for crack monitoring of a structure by measuring electrical responses without sensor installation. However, the electrical responses are often sensitively altered by temperature variation as well as crack initiation. The temperature variation may disturb crack detection on the measured electrical responses. Moreover, as sensing probes for measuring electrical reponses increase, undesired contact noises are often augmented. In this paper, a self-sensing impedance circuit is specially designed for reducing the number of sensing probes. The crack initiation and temperature variation effects on the self-sensing impedance responses of FRCCs are experimentally investigated using the self-sensing impedance circuit. The experiment results reveal that the electrical impedance response are more sensitively changed due to temperature variation than crack initiation.

• Proceedings of the Korea Concrete Institute Conference
• /
• 2006.11a
• /
• pp.653-656
• /
• 2006

High performance fiber-reinforced cementitious composite(HPFRCC) encompass a wide variety of cementitious composites whose behavior in tension is significantly more ductile than that of traditional fiber-reinforced concrete. Fibers in HPFRCC are increasingly being used for the reinforcement of cementitious matrix to enhance the toughness and energy absorption capacity and to reduce the cracking sensitivity of the matrix. In the past decade, HPFRCC have evolved with intensified research. HPFRCC for structural applications has been developed under the performance driven design approach. It is the aim of this study to obtain development of HPFRCC using polyvinyl-alcohol fiber(PVA). It was targeted a requirement of economic mixing and apply to structure member.

• Magazine of the Korea Concrete Institute
• /
• v.25 no.3
• /
• pp.39-42
• /
• 2013

• Proceedings of the Korea Concrete Institute Conference
• /
• 2004.05a
• /
• pp.28-31
• /
• 2004

This paper discusses the role of micro and macrofibers in the workability, compressive strength, and failure of cementitious composites. Workability(flow), compressive strength, splitting strength and fracture mechanism of hybrid fiber reinforced cement composites(HFRCC) have been investigated by means of Korean Standard (KS). The specific blend pursued in this investigation is a combination of polyvinyl alcohol(PVA) and steel cord. It was demonstrated that a hybrid combination of steel and PVA enhances fiber dispersion compared to only steel cord reinforced cement composites and that the brittle and wide cracking was much reduced in HFRCC as expected because in the matrix containing the PVA fiber around the steel cord, a multiple microcracking occurred and the steel cord could sufficiently work for bridging the cracked surface.