• Magazine of the Korean Society of Agricultural Engineers
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• v.39 no.4
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• pp.75-81
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• 1997

This study was performed to evaluate the engineering properties of surlightweight polymer concrete using synthetic lightweight aggregate. The following conclusions were drawn; 1. The unit weight was in the range of 0.849~0.969t/$m^3$, the unit weights of those concrete were decreased by 58 ~ 63% than that of the normal cement concrete. 2. The highest strength was achieved by $P_1$, and compressive strength was increased by 93% and bending strength by 364% than that of the normal cement concrete, respectively. 3. The ultrasonic pulse velocity was in the range of 2, 346~2, 702m/s, which was low compared to that of the normal cement concrete. 4. The dynamic modulus of elasticity was in the range of $1.561{\times} 10{^5}~1.916{\times} 10{^5}kgf/cm^2$, which was approximately 52~98% of that of the normal cement concrete. 5. The compressive and bending strength were increased with the increase of unit weight. But, the dynamic modulus of elasticity and ultrasonic pulse velocity were decreased with the increase of unit weight.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.427-430
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• 2005

The purpose of this study is to choose the right chemical admixture to reduce slump loss of lightweight aggregate concrete. So we compare 3 types of chemical admixture as measuring slump loss from mixing to 60 minutes. The lightweight aggregate of this study is made by clayt and dust from lots of industry. To save natures, we will use many types of industrial wastes and try to spend much making artificial aggregate.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.117-120
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• 2006

The purpose of this study is to efficiently treat the sewage sludge discharged from sewage treatment plants and evaluate the feasibility of the manufacture of lightweight aggregates(LWA) using a large quantity of sewage sludge. Sintered lightweight aggregate from sewage sludge is experimentally manufactured with various mass ratios of clay to sewage sludge by a pilot plant, and is tested for density, water absorption and crushing value. Their physical properties are compared to those of a commercial sintered lightweight aggregate. As a result, an experimentally manufactured lightweight aggregate is similar or superior in physical properties to the commercial lightweight aggregate. The manufactured lightweight aggregate could be used for structural concrete and non-structural concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2006.05b
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• pp.121-124
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• 2006

Lightweight aggregate is mainly consist of multi-crystalline structure. It may be abnormal water moving by the change of external circumstance because of its specific portion being between components and aperture. So it has some difficulty in forming without concise method about absorbing character and water-containing point even though it is used to water-containing condition over the 24 hours of absorbing amount in present. This study has main idea on the characteristics of absorption on the pressurization of lightweight aggregate.

• Proceedings of the Korea Concrete Institute Conference
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• 1993.10a
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• pp.118-123
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• 1993

The purpose of this study is to put to practical use the economical high-strength lightweight concrete manufactured by domestic materials, through the analysis on the properties of lightweight concrete with the natural zeolite and mud stone abundant in domestic and compare them with those with silica fume. As a result, it was possible to gain proper workability in the lightweight concrete with admixtures through using the superplasticizer. the optimum replacement rate of zeolite and mud stone powder is respectively 5~10%, 10~15% on unit-cement amount. The strength development rate for plain concrete is 27%, 18% at optimum replacement rate.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.157-160
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• 2005

The purpose of this study is to efficiently treat the sewage sludge discharged from sewage treatment plants and evaluate the feasibility of the manufacture of lightweight aggregates(LWA) using a large quantity of sewage sludge and inorganic waste binder ;f1y-ash, waste-stone, tailing, phosphogypsum. Then they were burned in different soak temperatures from 1190$^{circ}C$ to 1290$^{circ}C$ with fixed soak time and heating rate at 5 minutes and 20$^{circ}C$/min respectively in order to produce lightweight aggregate (LWA). Experiment were generated to evaluate the quality of LWA as well as the relationship between burning condition and product's quality.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.109-112
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• 2005

As civilization progresses amount of sewage sludge continues to increase from a sewage disposal plant with a huge expenditure of water resources. So It is necessary to reduce the high costs of sewage disposal and the pollution of the environment and also a unit cost of artificial lightweight aggregate by continual recycling. The purpose of this study is to put artificial lightweight aggregate concrete to practical use by using sewage sludge and clay

• Journal of the Society of Disaster Information
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• v.6 no.1
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• pp.78-90
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• 2010

Exposure to the outside, the concrete is differential moisture distribution depending on the depth. Such a differential moisture distribution causes the differential drying shrinkage in concrete structures. This thesis is researched to compare the shrinkage of lightweight concrete depending on depth to normal concrete. It is used artificial lightweight aggregate which has 20% of pre-absorb value by lightweight concrete. When water-binder ratio is 30%, average shrinkage of lightweight concrete section decreased than normal concrete, but differential shrinkage of lightweight concrete section increased. However water-binder ratio is 40% and 50% average shrinkage and differential shrinkage of lightweight concrete section decreased than normal concrete.

• Magazine of the Korean Society of Agricultural Engineers
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• v.37 no.5
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• pp.90-100
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• 1995

This study was performed to develop the lightweight concrete using synthetic lightweight aggregate and natural coarse aggregate. Mixing ratios were three types, the first type was mixed cement and synthetic lightweight fine aggregate (Type CP), the second type was mixed cement, synthetic lightweight fine aggregate and synthetic lightweight coarse aggregate (Type CPE), the third type was mixed cement, synthetic lightweight fine aggregate and natural coarse aggregate (Type CPN). The results of this study are summarized as follows ; 1. The W/C of each mixing ratio was increased with increase of the amount of cement used, and it was shown higher in order of Type CP, CPN, CPE. 2. The unit weight of Type CP, CPE and CPN was 1.473~1.647g/cm$^3$, 1.467~1.622g/cm$^3$ and 1.658~1 .838g/cm$^3$, respectively. And the absorption ratio was approximately 20%, which was higher than that of the normal cement concrete. 3. The compressive strength of Type CP was shown 178 ~249kg/cm2, Type CPE was shown 149~241kg/cm$^2$ and Type CPN was shown 196~297kg/cm$^2$, respectively. Each strength ratio was smaller than that of the normal cement concrete. 4. The pulse velocity of Type CP, CPE and CPN was 2, 688~3, 240m/sec, 2, 981~3, 324m/sec and 2, 989 ~ 3, 545m/sec, respectively. And it was increased with increase of strength and unit weight. 5. The length change ratio at 28 days was in the range of 0.057~0.077%, and earlier length change ratio was higher than that of the later.

• Korean Journal of Agricultural Science
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• v.18 no.1
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• pp.33-40
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• 1991

This study was performed to obtain the basic data applied to use of synthetic lightweight aggregate concrete affected by alkali silica reaction. The results obtained were summarized as follows; 1. The compressive strength of type A concrete was increased with increase of curing age. At the curing age 28 days, the highest compressive strength was showed at type Band C concrete, respectively. But, it was gradually decreased with increase of curing age at those concrete. 2. The flexural strength of type A concrete was increased with increase of curing age. At the curing age 14 days, the highest flexural strength was showed at type Band C concrete, respectively. But, it was gradually decreased with increase of curing age at those concrete. 3. The correlation between compressive and flexural strength of the sample was shown highly significant only at type A concrete. 4. It was shown that the water absorptions of the type Band C were 7.0-7.8 times higher than the type A concrete. It was significantly higher at the early stage of immersed time at all sample. 5. The correlation between compressive strength and water absorption of the sample was significant only at the type A concrete.