• Journal of the Korean Ceramic Society
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• v.50 no.6
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• pp.528-532
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• 2013

Well-dispersed slurries of submicron-sized alumina powders were pressure-infiltrated in 3D preforms of mullite fibers and the effects of the particle size and infiltration pressure on the particle packing characteristics were investigated. Infiltration without pressure showed that the packing density increased as the particle size decreased due to the reduction of the friction between the particles and the fibers. The infiltrated preforms contained large pores in the large voids between the fiber tows and small pores in the narrow voids between the individual fibers. Pressure infiltration resulted in a packing density of 77% regardless of the particle size or the infiltration pressure(210 ~ 620 kPa). Pressure infiltration shortened the infiltration time and eliminated the large pores in preforms infiltrated with the slurries of smaller particles. The slurry pressure-infiltration process is thus an efficient method for the packing of matrix materials in various preforms.

• Journal of the Korea Institute of Building Construction
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• v.17 no.2
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• pp.167-174
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• 2017

This research investigated the mechanical performance of slurry infiltrated high performance fiber reinforced cementitious composite (SI-HPFRCC) with high volume blast furnace slag powder. Hooked-end steel fibers (volume fraction of 6.4%) were used for the fabrication of SI-HPFRCC. A series of mechanical performance test was conducted including strength and toughness of SI-HPFRCC in compressive and flexural mode at four different ages. Compressive and flexural strength tests of the slurry matrix at the same ages were also conducted in order to evaluate fiber reinforcing effect on the mechanical performance. The flexural response of SI-HPFRCC shows an increasing brittleness with age. The compressive response also shows an increasing brittleness with age but the degree of brittleness is much lower than the flexural case. In terms of strength, SI-HPFRCC shows about 140~190% of compressive strength improvement and 440~500% flexural strength improvement comparing to the slurry matrix.

• Journal of the Korea institute for structural maintenance and inspection
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• v.4 no.3
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• pp.129-136
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• 2000

In the side of military purpose, the explosion proof concrete, which contributes to protect the military facilities from damages due to the explosion of bomb and to maintain their shapes, is required to develop, Therefore. in this paper, mechanical and explosion-proof properties of concrete are tested under various steel fiber contents and member size. According to the experimental results, compressive, tensile and flexural strength gain higher levels with an increase in fiber contents. It shows that energy bearing capacities are higher with an increase in fiber contents. Especially. it is confirmed that slurry infiltrated fiber concrete(SIFCON) gains high strength and has high energy bearing capacities. SIFCON is expected to be applied in the construction of explosion proof structures.

• Journal of the Korea Concrete Institute
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• v.18 no.5 s.95
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• pp.703-708
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• 2006

The slurry infiltrated fiber concrete(SIFCON) is recognized as one of the most promising new construction materials. Compressive and direct tensile tests are performed to investigate the mechanical property of SIFCON. Hooked-end steel fibers are used in the mix with fiber volume fraction varied from 4% to 10%. The water/cement ratio is kept constant at 0.4. The amount of silica fume added is 10% by weight of cement and 0.5% of water reducing agent is added to improve the workability of the slurry. The test results in this study show that the compressive strength of SIFCON is about 1.59 to 2.68 times in comparison with the cement paste. Tensile strength is showed the enhancement of about 2.51 to 8.77 times. It is also observed that the toughness and ductility of SIFCON are increased significantly with the increasing in fiber volume fraction.

• Computers and Concrete
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• v.26 no.3
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• pp.275-283
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• 2020

Reinforced concrete (RC) does not provide sufficient resistance against impacts and blast loads, and the brittle structure of RC fails to protect against fractures due to the lack of shock absorption. Investigations on improving its resistance against explosion and impact have been actively conducted on high-performance fiber-reinforced cementitious composites (HPFRCCs), such as fiber-reinforced concrete and ultra-high-performance concrete. For these HPFRCCs, however, tensile strength and toughness are still significantly lower compared to compressive strength due to their limited fiber volume fraction. Therefore, in this study, the tensile behavior of slurry-infiltrated fiber-reinforced cementitious composites (SIFRCCs), which can accommodate a large number of steel fibers, was analyzed under static and dynamic loading to improve the shortcomings of RC and to enhance its explosion and impact resistance. The fiber volume fractions of SIFRCCs were set to 4%, 5%, and 6%, and three strain rate levels (maximum strain rate: 250 s^-1) were applied. As a result, the tensile strength exceeded 15 MPa under static load, and the dynamic tensile strength reached a maximum of 40 MPa. In addition, tensile characteristics, such as tensile strength, deformation capacity, and energy absorption capacity, were improved as the fiber volume fraction and strain rate increased.

• Journal of the Korean Ceramic Society
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• v.45 no.4
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• pp.204-207
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• 2008

This paper presents a new process for producing SiC fiber-SiC matrix(SiC/SiC) composites by reaction sintering. The processing strategy for the fabrication of the SiC/SiC composites involves the following: (1) infiltration of the SiC fiber fabric using a slurry consisting of Si and C precursors, (2) stacking the slurry-infiltrated SiC fiber fabric at room temperature, (3) cross-linking the stacked composites, (4) pyrolysis of the stacked composites, and (5) hot-pressing of the pyrolyzed composites. It was possible to obtain dense SiC/SiC composites with relative densities of >96% and a typical flexural strength of ${\sim}400$ MPa.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.8
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• pp.39-45
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• 1998

In the previous study. the powder casting was attempted as the rapid tooling. The powder casting was the process to cast dry powder into the casting mold transferred from R/P model and infiltrate the liquid binder to solidify the powder. And then, the melted copper was infiltrated to control the shrinkage rate of the final mold Conseqently, the shrinkage rate was under 0.1% through that process. The mechanical characteristic was also excellent. Generally, in the slurry casting, the alumina powder and the water soluble phenol were mainly used. However, the mechanical property of the phenol was not good enough to apply to molds directly. In this study, aluminium powder filled with epoxy is applicated to the slurry casting to solve these problems. The mechanical and thermal properties are better than phenol because the epoxy is the thermosetting resin. We achieved a successful result that the shrinkage rate is shortened about 0.047%. Futhermore, the manufacturing time and cost savings are significant. Finally, we assume that the developing possibility of this process is very optimistic.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.4
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• pp.109-115
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• 2015

High performance fiber reinforced cementitious composite (HPFRCC) can provide high fracture energy absorption as well as high strength with high fiber volume fraction. The increased fracture energy helps resisting high frequency loadings, such as earthquake, impact or blast. This study investigates the flexural performance of slurry infiltrated fiber concrete (SIFCON), one of the important HPFRCC, with respect to varying fiber volume fraction. The maximum fiber volume fraction was 8.0 % and reduced to 6.0% by 0.5% and the maximum volume fraction is obtained by packing fibers with simple tapping by hands. The used fiber was a steel fiber with the length 30 mm and the diameter of 0.5 mm. The flexural strengths were 48.7 MPa at 8.0 % and 22.8 MPa at 6.0 %. The measured flexural strength is much higher compared to other cememtitious composite materials but decreased proportional to the fractions. This result implies that for SIFCON considered herein the reduced amount of steel fibers may affect its flexural performance in a negatively way. The flexural toughness, an index to represent the fracture energy absorption, also decreased with the reduced fiber amount.

• Advances in concrete construction
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• v.13 no.2
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• pp.123-132
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• 2022

This paper aims to adapt Multilinear regression (MLR) to predict the strength and toughness of SIFCON containing various pozzolanic materials. Slurry Infiltrated Fibrous Concrete (SIFCON) is one of the most common terms used in concrete manufacturing, known for its benefits such as high ductility, toughness and high ultimate strength. Assessment of compressive strength (CS.), flexural strength (F.S.), splitting tensile strength (STS), dynamic elasticity modulus (DME) and impact energy (I.E.) using the experimental approach is too costly. It is time-consuming, and a slight error can lead to a repeat of the test and, to solve this, alternative methods are used to predict the strength and toughness properties of SIFCON. In the present study, the experimentally investigated SIFCON data about various mix proportions are used to predict the strength and toughness properties using regression analysis-multilinear regression (MLR) models. The input parameters used in regression models are cement, fibre, fly ash, Metakaolin, fine aggregate, blast furnace slag, bottom ash, water-cement ratio, and the strength and toughness properties of SIFCON at 28 days is the output parameter. The models are developed and validated using data obtained from the experimental investigation. The investigations were done on 36 SIFCON mixes, and specimens were cast and tested after 28 days of curing. The MLR model yields correlation between predicted and actual values of the compressive strength (C.S.), flexural strength, splitting tensile strength, dynamic modulus of elasticity and impact energy. R-squared values for the relationship between observed and predicted compressive strength are 0.9548, flexural strength 0.9058, split tensile strength 0.9047, dynamic modulus of elasticity 0.8611 for impact energy 0.8366. This examination shows that the MLR model can predict the strength and toughness properties of SIFCON.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.303-306
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• 1999

For the purpose of Military means, explosion proof concrete, which protect the structures from the damage due to the explosion of bomb and maintain its shape, is required to develop. Therefore, in this paper, mechanical and explosionproof properties of concrete are tested under various steel fiber contents and member size. According to the experimental results, compressive, tensile and flexural strength go up with the increase of fiber contents. Energy bearing capacities is higher with the increase of fiber contents. Especially, it is confirmed that slurry infiltrated fiber concrete (SIFCON) gains in high strength and has high energy bearing capacities. SIFCON is expected to apply in the construction of explosion proof structures.