• Proceedings of the Korea Concrete Institute Conference
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• 1996.04a
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• pp.192-197
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• 1996

An experimental study was performed to examine the feasibility of using silicic wastes as construction materials for civil structures, and investigate its utility as a replacement for the favored nature resource to prevent the economic loss. In order to achieve this objective, mechnical properties of concrete containing silicic wastes is tested by investigating the strength development through parameters of water-binder ratios replacement 10 percent ratio with respect to curting conditions. The effect of stringth development is investigated for curing conditions when silicic wastes of 10 percent of cement-binder ratios is containde. Comparision on compressive strength of normal concrete and concrete containing silicic wastes at 28 day is conducted. The concrete with silicic wastes have larger compressive strength than of normal concrete by about 20 percent, when cured at 80 degree. The wastes concrete using silica sand shows increased strength, fracture toughness, elastic modulus and strain than the normal concrete, although the silicic wastes concrete could be able to satisfy the generally required strength for conventional concrete structures.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.323-328
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• 1997

The strength of concrete depends on factors of materials, composition and manufacturing method. Among these factors, preparatory experiments are to consider and analyze the factors on compressive strength of ultra-high strength concrete according to types of aggregate, binder content, water-binder ratio, and curing methods. And the final experiment to develop the ultra-high strength over 3,000kgf/$\textrm{cm}^2$ is based on these preparatory experiments. As the result of this final expriment. We could manufacture the ultra-high strength concrete with a marvelous compressive strength concrete with a marvelous compressive strength of 3,116kgf/$\textrm{cm}^2$. This study is to compare and analyze the manufacturing system of ultra-high strength concrete of 3,116kgf/$\textrm{cm}^2$ compressive strength in the side of material development of construction industry.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.05a
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• pp.199-200
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• 2023

This paper presents a study on the selection of optimal mix proportions for producing lightweight pre-foam concrete as a substitute for Autoclaved Lightweight Concrete (ALC) without the accelerated curing. The study was conducted using a rapid hardening binder made from by-products of the steel industry as the primary raw material. The experimental results established the optimal mix proportions, which included retarder content, water/binder ratio, foam content, and fiber inclusion amount, for the production of lightweight foam concrete. The optimal mix proportion was determined to have a retarder content at the minimum amount required to secure the working time, W/B of 35%, a foam content limited to 65% or less, and a fiber inclusion amount of 0.05% or less.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2023.11a
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• pp.81-82
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• 2023

As part of a study to utilize recycled aggregates in the construction industry, this paper attempted to examine recycled aggregates from waste concrete, a construction waste, and red mud, an industrial by-product, by applying them to earthen concrete packaging materials. As a result, it was found to satisfy the compressive strength standards for parking lots of SPS-KSCICO-001-2006, and its applicability in the construction industry was judged.

• Journal of the Korea Concrete Institute
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• v.11 no.3
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• pp.123-130
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• 1999

In a preceding study(1), the using method of garnet powder has been studies through the various investigation of basic material properties on garnet powder, industrial by-products generated in Yungju, Kyungpook. In this study, the various properties of concrete mixed with garnet powder are examined as following condition : Unit weight of water (170kg/㎥), water-binder ratio W/B (53, 55 and 58%), sand-aggregate ratio (S/A) (43, 45 and 48%), substitutional ratio of garnet powder of 0, 5, 10, 15 and 20%. Slump increased a little as the substitutional ratio of garnet increased. Air content decreased a little at the substitutional ratio of 10%. or more. Though there is a little difference in compressive strength according to the W/B and the substitutional ratio, compressive strength of concrete using garnet exceeded that of plain concrete a little in the range of the substitutional ration of 5 to 15%. Also, There is a similar tendency in the tensile and flexural strength. Therefore, the use of garnet powder with industrial by-products is expected to improve the workability and the strength of concrete.

• Computers and Concrete
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• v.17 no.6
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• pp.787-799
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• 2016

Climate anomalies in recent years, numerous natural disasters caused by landslides and a large amount of entrained sands and stones in Taiwan have created significant disasters and greater difficulties in subsequent reconstruction. How to respond to these problems efficaciously is an important issue. In this study, the sands and stones were doped with recycled materials (waste LCD glass sand, slag powder), and material was mixed for recycled ready-mixed soil. The study is based on security and economic principles, using flowability test to determine the water-binder ratio (W/B=2.4, 2.6, and 2.8), a fixed soil: sand ratio of 6:4 and a soil: sand: glass ratio of 6:2:2 as fine aggregate. Slag (at concentrations of 0%, 20%, and 40%) replaced the cement. The following tests were conducted: flowability, initial setting time, unit weight, drop-weight and compressive strength. The results show that the slump values are 220 -290 mm, the slump flow values are 460 -1030 mm, and the tube flow values are 240-590 mm, all conforming to the objectives of the design. The initial setting times are 945-1695 min. The unit weight deviations are 0.1-0.6%. The three groups of mixtures conform to the specification, being below 7.6 cm in the drop-weight test. In the compressive strength test, the water-binder ratios for 2.4 are optimal ($13.78-17.84kgf/cm^2$). The results show that Recycled ready-mixed soil materials (RRMSM) possesses excellent flowability. The other properties, applied to backfill engineering, can effectively save costs and are conducive to environmental protection.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.3
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• pp.83-91
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• 2015

Porous concrete consists of cement, water and coarse aggregate and has been used for the purpose of decreasing the earth environmental load such as air and water permeability, sound absorption, etc. However, the physical and mechanical properties of porous concrete changes due to compaction load during construction. For such a reason, the purpose of this study is to investigate the physical and mechanical properties of porous concrete according to the kinds of binder, the ratio of water to binder and target void ratio. In particular, this study has been carried out to investigate the influence of compaction load on the void ratio, strength and coefficient of permeability. Aggregate used in this study are by-products generated during production of crushed gravel with a maximum size of 13mm. The results of this study showed that the target void ratio, the coefficient of permeability and compressive strength of porous concrete had a close relationship with the void ratio, and it will be possible that the void ratio is suggested by the mix design of porous concrete. The compressive strength of porous concrete was the highest at the content of the expansive admixture of 5% and compared to non-mixture, 10% mixture of silica fume improved compressive strength about 32%. And in the result of the study to change the compaction load, the compressive strength increased from the load of 15kN, the void ratio decreased from the load of 0.8kN, the coefficient of permeability decreased from the load 35kN, respectively.

• Geomechanics and Engineering
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• v.14 no.6
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• pp.533-544
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• 2018

The importance of using materials cost effectively to enhance the strength and reduce the cost, and weight of earth fill materials in geotechnical engineering led researchers to seek for modifying the soil properties by adding proper additives. Lightweight fill materials made of soil, binder, water, and Expanded polystyrene (EPS) beads are increasingly being used in geotechnical practices. This paper primarily investigates the behavior of sandy soil, modified by EPS particles. Besides, the mechanical properties of blending sand, EPS and the binder material such as fly ash and cement were examined in different mixing ratios using a number of various laboratory studies including the Modified Standard Proctor (MSP) test, the Unconfined Compressive Strength (UCS) test, the California Bearing Ratio (CBR) test and the Direct Shear test (DST). According to the results, an increase of 0.1% of EPS results in a reduction of the density of the mixture for 10%, as well as making the mixture more ductile rather than brittle. Moreover, the compressive strength, CBR value and shear strength parameters of the mixture decreases by an increase of the EPS beads, a trend on the contrary to the increase of cement and fly ash content.

• Structural Engineering and Mechanics
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• v.86 no.2
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• pp.181-195
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• 2023

To predict the rheological behaviours along with the compressive strength of self-compacting concrete that incorporates environmentally friendly ingredients as cement substitutes, a comparative evaluation of machine learning methods is conducted. To model four parameters, slump flow diameter, L-box ratio, V-funnel time, as well as compressive strength at 28 days-a complete mix design dataset from available pieces of literature is gathered and used to construct the suggested machine learning standards, SVM, MARS, and Mp5-MT. Six input variables-the amount of binder, the percentage of SCMs, the proportion of water to the binder, the amount of fine and coarse aggregates, and the amount of superplasticizer are grouped in a particular pattern. For optimizing the hyper-parameters of the MARS model with the lowest possible prediction error, a gravitational search algorithm (GSA) is required. In terms of the correlation coefficient for modelling slump flow diameter, L-box ratio, V-funnel duration, and compressive strength, the prediction results showed that MARS combined with GSA could improve the accuracy of the solo MARS model with 1.35%, 11.1%, 2.3%, as well as 1.07%. By contrast, Mp5-MT often demonstrates greater identification capability and more accurate prediction in comparison to MARS-GSA, and it may be regarded as an efficient approach to forecasting the rheological behaviors and compressive strength of SCC in infrastructure practice.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.288-291
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• 2004

In this paper, to make ultra-high strength SFRCC with the range of compressive strength 180MPa, it was investigated the constitute factors of ultra-high strength SFRCC influenced on the compressive strength. The experimental variables were water-cementitious ratio, replacement of silica fume, size and proportion of sand, type and replacement of filling powder, and using of steel fiber in ultra-high strength SFRCC. As a result, in water-binder ratio 0.18, we could make ultra-high strength SFRCC with compressive strength 180MPa through using of silica fume, quartz sand with below 0.5mm, filling powder and steel fiber.