• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.232-236
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• 1993

The Tunnel Form(T/F) system instead of traditional euro form has been tried to reduce construction duration and to improve concrete quality in reinforced concrete wall type apartment construction. To find the relationship for concrete compressive strength between cylinder mold and slab, the different curing locations of concrete cylinder mold in the room have been investigated. The test results showed that the compressive strength of the cylinder concrete with middle-upper location in the room was most near concrete compression strength with respect to slab concrete strength.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.350-354
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• 1995

This paper is about impact behavior of cylinder container, made of steel fiber reinforced polymer-impregnated concrete(SFPIC), for intermediate and low level radwaste disposal. In order to obtain the material properties of the SFPIC, steel ball impact tests were done to SFPIC beams and its simulation by finite element method was performed. By using the material properties in finite element impact analysis of the SFPIC concrete cylinder, we obtained impact behavior of the cylinder.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.149-150
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• 2009

The effective ratio of the concrete delivery cylinder has meaning which is important in the performance analysis of stationary concrete pump. But, from experiment or test of most it assumes the effective ratio of the concrete delivery cylinder simply to 90${\sim}$95% level and it is applying. It will follow hereupon and it will be able to grasp the performance of stationary concrete pump by mistake. So we confirm a discharge quantity per time consequently and with, accurately to measure the effective ratio of the concrete delivery cylinder there is a necessity which it will analyze. Experimental resultant existing presumed it apppeared with the fact that it is visible the low-end 70${\sim}$75% level which it sees.

• Journal of the Korea Concrete Institute
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• v.15 no.1
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• pp.155-161
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• 2003

This paper presents experimental and analytical results of glass fiber-reinforced concrete (GFRC) and polypropylene fiber-reinforced concrete (PERC) to investigate the relationship between tensile strength and compressive strength based on the split cylinder test (ASTM C496) and compressive strength test (ASTM C39). Experimental studies were performed on cylinder specimens having 150 mm in diameter an 300 mm in height with two different fiber contents (1.0 and 1.5％ by volume fraction) at ages of 7, 28 and 90 days. A total of 90 cylinder specimens were tested including specimens made of the plain concrete. The experimental data have been used to obtain the relationship between tensile strength and compressive strength. A representative equation is proposed for the relationship between tensile strength and compressive strength of fiber-reinforced concrete (FRC) including glass and polypropylene fibers. There is a good agreement between the average experimental results and those calculated values from the proposed equation.

• Computers and Concrete
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• v.16 no.1
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• pp.179-190
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• 2015

An experimental program has been carried out to investigate the effect of edge-slope on compressive strength of concrete specimens. In this study, effect of such slope was investigated by testing 100 standard cylinder specimens and 40 standard cubes. When molds are put on a slanted place, wet concrete starts to flow through the open end of mold. It keeps flowing until it reaches to a parallel surface with the place over which it was placed. That creates a sloped surface over the loading area. Experimental results revealed significant relationships between failure loads and slope of loading surface for cylinders. Angled cracks occurred in sloped cylinder specimens. Tension cracks occurred in cube specimens. Fracture mechanisms were also evaluated by using finite element analyses approach. Experiments yielded an exponential curve with bandwidth for cylinders. Average value of curve is $y={\frac{\pi}{2}}e^{-cf}$ between slope and compressive strength. Inclination is much effective parameter for cylinders than cubes.

• Advances in concrete construction
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• v.3 no.1
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• pp.39-54
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• 2015

Relative humidity and strains within a massive concrete cylinder (${\varphi}450mm{\times}900mm$) in the drying and the re-saturating process were measured for elucidating the process of ASR surface cracking in concrete. The expansion behavior of mortars in dry atmospheres with various R.H. values and the resaturating process was revealed. Non- or less-expansive layers were formed in near-surface regions in the concrete cylinder in the drying process, but ASR expansions actively progressed in inner portions. After resaturating, R.H. values of near-surface regions rapidly increased with time, but expansions in the regions were found to be very small. However, in the middle portions, of which R.H. values were kept 80% ~ 90% R.H. in the drying process, expansion actively progressed, resulting in further development of surface cracks in the re-saturating process.

• Magazine of the Korean Society of Agricultural Engineers
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• v.30 no.2
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• pp.82-94
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• 1988

The purpose of this study is to introduce the Double Punch test method which is an indirect testing method of tensile strength of concrete, and to compare with the tensile strength of concrete as determined by the split-cylinder test, a practical method for performing the Double Punch test to obtain the tensile strength of concrete is proposed and recommended for general use. In this study, the dimensions of cylindrical specimens used in the Double-Punch test were 15X30cm, 15X15cm, 10${\times}$(20cm, and 5${\times}$l0cm, and in the split-cylinder test were 15${\times}$(30cm, 15${\times}$(15cm, and 10${\times}$(20cm. And the diameters of loading punches used in the Double-Punch test were 1.5cm, 2.5cm, and 3.5 cm. The results obtained from tests are summarized as follows ; 1. In the split-cylinder test, the tensile strength of concrete by the linear elasticity theory is similar to that of plasticity theory. 2. Both split-cylinder test and Double-Punch test, tensile strength of concrete is increased with decreasing specimen size. This tendency is identical when the ratio of specimen diameter to height is 1: 2, but that tendency is quite different when the ratio is 1: 3. In the Double-Punch test, if specimen size is constant, by increasing the punch size, tensile strength of concrete is increased, too. 4. Using a 15 ${\times}$( 15 cm cylinder specimen and 3.5 cm diameter punch in the Double Punch test would give the most uniform and consistent result in tensile strength, and the result showed a gQod correlation with splitting tensile strength from 15 x 30cm specimen. 5. In order to obtain satisfactory results and to nuninuze variability, it is proposed that specimens of 15 cm in diameter and 15 cm in height with two 3.5 cm diameter punches should be used. It seems, therefore, reasonable tt) take f't=0.0024 P(kg / cm$^2$) as a working formula for computing the tensile strength in the Double Punch test for concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.101-106
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• 2001

This paper presents experimental results for the confining characteristics of cylinder with center-hole and spiral reinforcements. The experiments have been conducted for the specimens with primary variables i.e., spiral reinforcement ratio and diameter of center-hole which affect the compressive strength and stress-strain relationship. Through this research, it was found that the compressive strength and ductility were increased with the ratio of spiral reinforcement because the lateral expansion of the concrete inside the spiral was restrained by the spiral, but dependent on the size of center-hole.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 1995.10a
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• pp.171-177
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• 1995

Fracture mechanics does work for concrete, provided that one uses a proper, nonlinear form of fracture mechanics in which a finite nonlinear zone at fracture front is being considered. The fracture process zone is a region ahead of a traction-free crack, and the development of model of fracture process zone is most important to describe fracture phenomena in concrete. This paper is about fracture behavior of concrete cylinder under lateral pressure. Concrete cylinders were made of high strength normal connote, steel fiber reinforced concrete and steel fiber reinforced polymer-impregnated concrete and concrete and the fracture behavior such as cracking propagation and ultimate load are observed. The fracture process zone is modelled by a Dugdale-Barenblatt type model with linear tension-softening curve and are implemented to the boundary element technique for the fracture analyses of the cylinders. The experimental results are compared with analysis results and tension-softening curves for the steel fiber reinforced concrete and steel fiber reinforced polymer-impregnated concrete are obtained by back analyses.

• Magazine of the Korea Concrete Institute
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• v.3 no.4
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• pp.44-52
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• 1991