• Computers and Concrete
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• v.31 no.6
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• pp.485-499
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• 2023

Both damage and unsaturated conditions accelerate the transport of erosive media inside concrete. However, their combined effects have not been fully investigated. A multiscale mortar model using representative volume elements is developed, capturing the number and distribution in each phase. Afterwards, mortar damage microstructure evolution is simulated in the tensile process. Finally, the unsaturated mortar transport is predicted and analysed. The results indicate that damage significantly affects the diffusion process in the early stage, while the transport performance is weakened due to the obstruction of the nontransport phase in the later stage. The higher the saturation and the more connected pores, the faster the diffusion rate of chloride ions. Chloride ions spread around the cracks in a tree-like manner along. The model can very well predict the chloride ion transport performance of unsaturated and damaged mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.371-376
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• 2001

The purpose of this study is to investigate toughening of unsaturated polyester resin by addition of polyuretane liquid rubber. In general, unsaturated polyester resin has strong brittleness in spite of its high strength Therefore; it is difficult to use unsaturated polyester mortar for the place where impact resistance is demanded. In this study, it was evaluated strength and Gf by using to polyurethane liquid rubber. As a result, the toughness of unsaturated polyester mortar was increased by polyuretane liquid rubber.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.11a
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• pp.129-134
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• 2001

The purpose of this study is to investigate properties of unsaturated polyester mortar using the shale as find aggregates. To evaluate properties of unsaturated polyester mortar using crushed sand from Black shale, Red shale, Gray shale, we peformed the experiment according the F/B ratio of 25, 30, 35% and the volume of fine aggregate of 50, 53, 56%. The Result of this study is as follows. the strength of unsaturated polyester mortar is higher than those of river sand. The F/B ratio is higher and the volume of find aggregate is lower, the strength of unsaturated polyester mortar is higher

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2003.10a
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• pp.379-382
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• 2003

In this study, methyl methacrylate (MMA)- modified unsaturated polyester mortar, in which the MMA was added to the unsaturated polyester resin, was developed for improving the early-age strength and the workability of the conventional polymer concrete, binder of which was the unsaturated polyester resin. Then the strength properties of the MMA-modified unsaturated polyester mortar were surveyed. The experimental results showed that early-age strength was greater when the MMA contents were increased in the range of $20{\sim}40%$, but the strength rather showed a tendency of decrease when the MMA contents was 50%.

• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.332-335
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• 2004

Polymethyl Methacrylate(PMMA) mortars using EPS solution-based binders are prepared with various unsaturated polyester resin(UP) contents of binder, and tested for working life. heat exothorm temperature, length change. compressive strength and temperature dependence of compressive strength. As a result, the working life of PMMA mortar is lengthened with raising UP content of binder. Length change of the mortar was condensed from expansion to shrinkage with increasing UP content, and non shrinkage of the mortar is obtained at about UP content of $2.5\%$. The compressive strength of the mortar is increased with an increase in the UP content and reach maximum at UP content of $5\%$. However thermal resistance improvement of the mortar by increasing UP content was not recognized. UP resin was recommended as an effective agent for shrinkage control and strength development of PMMA mortar.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10b
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• pp.1133-1138
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• 2000

The interface necessarily exists in joints using cement mortar, UP(Unsaturated Polyester : UP) mortar and SBR(SBR-latex) mortar. Characteristics of shear transfer in joint interface consisting of different materials are studied with experimental and analytical methods. The uniaxial compressive shear experiments are accomplished with various angle of inclination (35, 45, 55, 65, 75°), materials of old and new-cast mortar. In this study, The results are as follows ① Mohr-coulomb's slip theory be applied to the interface consisting different materials ② The cohesion of UP mortar is superior to that f cement mortar, SBR mortar.

• Journal of the Korea Concrete Institute
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• v.14 no.3
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• pp.283-290
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• 2002

Generally polymer mortar and concrete using unsaturated polyester resin has high strengths and good chemical resistance. However it also has high brittleness and because of this reason, it is not used for the purpose that demands high resistance to impact. The purpose of this study is to improve the brittleness of unsaturated polyester mortar(UPE mortar) which could be used for the flooring material with recycled aggregates and UPE. Polyurethane liquid rubber(PU) and recycled aggregates were used to complement the brittleness and to recycle the resources respectively. The characteristics of mortar were investigated according to the molecular weight and substitution rate of PU. As the molecular weight and PU substitution rate were increased, the viscosity was increased, working life became fast and curing shrinkage was reduced. Compressive and flexural strengths were also reduced but tile brittleness was improved. Therefore, it is seemed that the improved WE mortar could be obtained by using polyurethane liquid rubber with the polyol of molecular weight 2000, 3000.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1998.10a
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• pp.107-112
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• 1998

The objective of this study was to develop a polymer mortar defensive block with high strength and durability using unsaturated polyester resin to complement defects of conventional cement mortar defensive block. Physical and mechanical properties of the polymer mortar defensive block were also investigated. Low absorptivity, high impact strength, and great bending strength of the polymer mortar defensive block was compared with those of the conventional cement defensive block. In conclusion, the polymer mortar defensive block is excellent and useful as industrial products for erosion control works.

• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 1999.10c
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• pp.330-335
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• 1999

The objective of this stu요 was to develop a polymer mortar guide block for the blind handicapped people. A high strength and a long durability polymer concrete using unsaturated polyester resin was used to developed the block and to improve the exiting cement mortar guide bloc. Physical and mechanical properties of the polymer mortar guide block were investigated with respect to absorptivity, impact strength, bending strength compared to those of the conventional cement guide block. The polymer mortar guide block was proven to have properties , indication that the block have better industrial applications.

• KCI Concrete Journal
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• v.11 no.3
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• pp.89-97
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• 1999

The purpose of this research is to investigate the utilization of recycled fine aggregates as a material to apply to a building finished walls or as a decorating material in combination with a polymer. The strengths of two resin mortars using recycled fine aggregates and natural fine aggregates was made. In order to improve the workability and the strength of the resin mortar with recycled fine aggregates, partial replacement of recycled fine aggregates with natural ones was made with the application of various type of fillers. The results, it show that the compressive strength and flexural strength of resin mortar using the recycled fine aggregates were about 70% to 100% of those of resin mortar using natural fine aggregates. It was enough to assure the utilization of the recycled fine aggregates as a material for the production of resin mortar. From the result of partial replacement of recycled fine aggregates with natural ones, the compressive strength was Increased from 5% to 15% and the flexural strength was much as 5% to 20% as a result of 70% substitution It was also found that the use of garnet powder shows a similar tendency in the compressive strength and slag powder does in the flexural strength and tensile strength.