• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.77-80
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• 1999

Before the field applications, several basic laboratory test were the characteristics of workability and strength of the concrete containing CSA expansive additive. As a result, high strength concrete using CSA expansive additive show similar workability and compressive to that of plain concrete, the optimum replacement ratio of them to plain concrete were obtained for CSA expansive additive 10%. On the other hand, it can be concluded that the use of CSA component is effective to prevent shrinkage crack reducing concrete using superplasticizer and to achive volume stability of concrete structure.

• International Journal of Concrete Structures and Materials
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• v.18 no.2E
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• pp.73-77
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• 2006

This paper shows a study of the efficiency of expansive additive and shrinkage reducing admixture in controlling restrained shrinkage cracking of high performance concrete at early age. Free autogenous shrinkage test of $100{\times}100{\times}400mm$ concrete specimens and simulated completely-restrained test with VRTM(variable restraint testing machine) were performed. Creep and autogenous shrinkage of high-performance concrete with and without expansive additive and shrinkage reducing admixture were investigated by experiments that provided data on free autogenous shrinkage and restrained shrinkage. The results showed that the addition of expansive additive and shrinkage reducing admixture effectively reduced autogenous shrinkage and tensile stress in the restrained conditions. Also, it was found that the shrinkage stress was relaxed by 90% in high-performance concrete with and without expansive additive and shrinkage reducing admixtures at early age.

• Journal of the Korea Institute of Building Construction
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• v.7 no.3
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• pp.123-130
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• 2007

This study investigated the fundamental properties and shrinkage properties of high performance concrete with water/binder ratio of 0, 30 and with combination of expansive additive and shrinkage reducing agent. According to the results, the fluidity of high performance concrete showed lower the using method in combination with expansive additive and shrinkage reducing agent than the separately using method of that, so the amount of superplasticizer increased when the adding ratio of expansive additive and shrinkage reducing agent increased. However the air content of concrete increased when used in combination with expansive additive and shrinkage reducing agent, so the amount of AE agent decreased. The compressive strength showed the highest at 5% of expansive additive, and decreased with an increase of the amount of shrinkage reducing agent. Furthermore, in order to reduce the shrinkage of high performance concrete, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than separately using method of that. Autogenous shrinkage was predicted using JCI model. Because JCI model is unable to consider the effect of EA and SRA, correction factor should be added to enhance the accuracy.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.11a
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• pp.679-682
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• 2005

The effects of substituting cement with fiber addition(poly vinyl alcohol), fly ash and Expansive Additive on the control of microcrack and enhanced durability performance of face slab concrete in concrete-faced rockfill dam was studied experimentally The laboratory test results shown that the mixture of fiber containing concrete and of fly ash replacement of concrete to be more effective than expansive additive concrete in the crack control and mechanical performance.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.620-626
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• 1997

In this study. use if CSA expansive additive for concrete is discussed, particulary applications to partial compacting the concrete structure of spillway gate located in Youngjong new airport construction field. Before the field applications, several basic laboratory test were carried out in order to clarify the material characteristics and to decide mix proportions. As the result the concrete using CSA expansive additive show similar workability and compressive strength to that of OPC concrete. Forethemore, it can be concluded that the use of CSA component is effective to prevent shrinkage crack and to achive volume stabiliy of concrete structure.

• Magazine of the Korean Society of Agricultural Engineers
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• v.42 no.6
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• pp.115-121
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• 2000

The purpose of this research is to investigate properties and field application of non-shrinkage high strength concrete containing expansive additive. Before the field applications, several basic laboratory test are performed to evaluate the characteristics of air content, workability and strength of the concrete using calcium sulfa aluminate(CSA) expansive additive. As a result, high strength concrete using CSA expansive additive show similar workability and compressive strength to that normal concrete, and the optimum replacement ratio of them is obtained by 10% CSA expansive additive. Accordingly, it can be concluded that the use of CSA expansive additive is effective to prevent shrinkage crack and to achieve volume stability of concrete structure.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.11a
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• pp.683-686
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• 2004

In recent years, some attention was particularly given to cracking sensitivity of high performance concrete. It has been argued and demonstrated experimentally that such concrete undergoes autogenous shrinkage due to self-desiccation at early age, and, as a result, internal tensile stress may develop, leading to micro cracking and macro cracking. One possible method to reduce cracking due to autogenous shrinkage is the addition of expansive additive. Tests conducted by many researches have shown the beneficial effects of addition of expansive additive for reducing the risk of shrinkage-introduced cracking. However, the research on hydration model of expansion additive has been hardly researched up to now. This paper presents a study of the hydration model of Ettringite-Gypsum type expansive additive. Result of comparing forecast values with experiment value, proposed model is shown to expressible of hydration of expansive additive.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.818-821
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• 2004

Generally, the high performance concrete of drying cracking and autogenous shrinkage are tend to be increased. In the previous study, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than the separtely using method of that. This study is to investigated the durability of high performance concrete using expansive additive and shrinkage reducing agent. Test results showed that the high performance concrete using expansive additive and shrinkage reducing agent had very good not only the durability performance such as salt injury, carbonation, resistance to freezing-thawing and permeability but also the resistance to shrinkage.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.283-288
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• 1999

This study is performed to evaluate slump , air content, compressive strength and length change ratio of non-shrinkage high strength ocncrete is achieved by 10% expansive additive contained. The length change ration of non-shrinkage high strength concrete which is in water curing, shows 0.055% expansion in 10% expansive additive contained concrete and 0.308 expansion in 20% expansion additive contained concrete when it is curing 28 days.

• Journal of the Korea Concrete Institute
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• v.16 no.5 s.83
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• pp.605-612
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• 2004

This study investigated the fundamental properties and shrinkage properties of high performance concrete with water/binder ratio of 0, 30 and with combination of expansive additive and shrinkage reducing agent. According to the results, the fluidity of high performance concrete showed lower the using method in combination with expansive additive and shrinkage reducing agent than the separately using method of that, so the amount of superplasticizer increased when the adding ratio of expansive additive and shrinkage reducing agent increased. However the air content of concrete increased when used in combination with expansive additive and shrinkage reducing agent, so the amount of AR agent decreased. The compressive strength showed the highest at $5\%$ of expansive additive, and decreased with an increase of the amount of shrinkage reducing agent. Furthermore, in order to reduce the shrinkage of high performance concrete, it was found that the using method in combination with expansive additive and shrinkage reducing agent was more effective than separately using method of that. Therefore, it analyzed that the combination of expansive additive of $5\%$ and shrinkage reduction agent of $1\%$ was the most suitable mixture, considering to the fluidity, strength and shrinkage under the condition of this experiment.