• Advances in concrete construction
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• v.13 no.5
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• pp.395-410
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• 2022

This study collected the results of material tests and full-scale pumping tests using 127 types of concrete mixtures with compressive strength ranging from 24 to 200 MPa. The results of 242 material tests showed high correlations between the viscosity of the lubricating layer and concrete, between the slump and the yield stress of concrete, between the water-binder ratio and the viscosity of lubricating layer, and between the time required to reach 500 mm of slump flow and concrete viscosity. Based on these correlations, pumpability was predicted using 101 pumping test conditions, and their accuracy was compared to the actual test results. When the rheological properties of concrete and the lubricating layer were directly measured, the prediction result showed the highest accuracy. A high accuracy can be achieved when the measured viscosity of the lubricating layer, a key determinant of concrete pumpability, is reflected in the prediction of pumpability. When measuring rheological properties is difficult, the slump test can be used to quantitatively predict the pumpability despite the lower accuracy than those of other prediction methods.

• Journal of the Korea Institute of Building Construction
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• v.15 no.2
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• pp.153-160
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• 2015

The marble powder is a by-product that can be freely collected during the manufacturing process of marble, such as sawing, shaping, and polishing. Disposal of this waste powder is one of the environmental problems worldwide today. Therefore, this study investigated to solve this problem by consuming the waste marble powder in high fluidity concrete, as a pore filler. For this purpose, the waste marble powder was used as a binder replacing 5%, 10%, 15%, and 20% of cement in high fluidity concrete. After mixing, slump flow test, time-to-reach the slump flow of 500mm test, O-lot test and U-box test were conducted with fresh concrete. For the hardened concrete, compressive strength was determined at the age of 28 days. According to the test results, the workability of high fluidity concrete increased with the powder of 15% replacement, and the compressive strength of high fluidity concrete also increased with the same amount of powder.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.220-226
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• 1997

High flowing concrete has flowability, passability, segregation resistance and so on, and there are so many influence factor to affect to fluidity of high flowing concrete, therefore it is so difficult to evaluate exactly the properties in fresh state. This study is to analyze and evaluate thefluidity of high flowing concrete affected by fine aggregate with test method such as, slump-flow test, V-lot test, L-flow test, Box filling test.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.7
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• pp.237-244
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• 2016

The workability of mortar determines its construction performance in a structure showing its designed resistance to external loads. Measuring the rheological properties of mortar is one way of quantifying its workability, but its field-applications are limited due to economical and spatial issues. The robustness of the slump flow test allows its use for evaluating the workability of mortar, even though it is a rather qualitative test method. This paper proposes a channel flow test and develops a correlation between its result and the rheological properties of mortar. The volume-of-fluid simulation for the channel flow test was accomplished, and a numerical database for the correlation was composed. A correlation model to estimate the rheological properties of mortar using the results of the channel flow test as inputs is proposed.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.42-47
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• 1995

The flow properties of xoncrete depend on form of fine aggregate, the ratio of voides of fine aggregate and cement paste So, in this study, investigated for the improvement of rheology properties on mortar and paste replaced by Zeolite $\circled1$ The slump flow have to do with correlation on yielding value of mortar respectirely. $\circled2$The increase ratio of strength Mortar and paste 10% replaced by Zeolite was presented significently but the slump flow was decteased stiffly as the increase of plastic viscosity at the ratio of replacement over 10%

• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.10
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• pp.271-279
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• 2016

This study examines the properties of high-fluidity concrete after adding copper slag as a mineral admixture. For this purpose, the replacement ratio of cement to copper slag was varied to 0, 10, 20, 30, 40, and 50%. A slump flow test, reach time slump flow of 500 mm, and a U-Box and O-lot test were conducted on the fresh concrete. The compressive strength of the hardened concrete was determined at 3, 7, 14 and 28 days. According to the test results, the workability, compaction, and compressive strength of the high-fluidity concrete increased when replacing 30% of the cement with copper slag. These parameters decreased for all material ages with more than 30% copper slag, which was the optimal mixture ratio.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.11a
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• pp.23-26
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• 2003

Metakaolin is a cementitious material for producing high-strength concrete. This material is now used as substitute for silica-fume. In this paper, we studied the properties of fresh concrete such as slump-flow, air content, and the feature of strength of hardened concrete according to the substitute ratio of metakaolin, silica-fume. In the fresh concrete test, the time depend loss of slump-flow & air content is good to 10-15% substitute ratio of metakaolin. And, in the strength test, 10-15% substitute ratio of metakaolin is good for producing high-strength concrete also. But, allowing for economical efficiency, we concluded that 10% is a adequate substitute ratio for producing high performance concrete.

• Proceedings of the Korea Concrete Institute Conference
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• 2003.05a
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• pp.1077-1080
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• 2003

High reactivity metakaolin (HRM) is a manufactured pozzolan produced by thermal processing of purified kaolinitic clay. Field performance and laboratory research of concrete containing HRM have demonstrated its value for bridge decks, bridge deck overlays, high-strength concrete and masonry products. This paper discusses laboratory evaluations to assess the physical properties of antiwashout underwater concrete (AWC) containing HRM, such as pH value, suspended solids, slump flow, and compressive strength. There were not much variations of pH value with the changing HRM contents, but suspended solid test showed that the amount of suspended solids of AWC with 10 and 20% of HRM were reduced in comparison with plain. Due to the fast hydration and reaction property of HRM, slump flow was decreased with increasing HRM contents. According to the results of compressive strength test, AWC with 10 and 20% of HRM showed higher strength characteristic than plain at all curing ages.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05b
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• pp.45-48
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• 2005

Self compacting concrete has the strong point in capability of concrete to be uniformly filled and compacted in every corners of formwork by its self-weight without vibration during placing. However, powder type self compacting concrete has the weak point in the heat of hydration, the drying shrinkage and the elastic property of concrete etc. Recently viscosity agent has been developed in order to overcome these weaknesses. In this study, self compacting concrete is made with viscosity agent based on polysaccharide derivative in order to develope the normal strength self compacting concrete. Slump flow, loss of slump flow and setting time are measured for comparison with normal concrete. Compressive strength, freezing and thawing test and carbonation test are conducted on normal and self compacting concrete using viscosity agent. In the experiment, we acquired good results in fresh and hardened self compacting concrete using viscosity agent based on polysaccharide derivative.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.129-130
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• 2021

For the development of high-fluidity concrete using low-binder, The effect of the use of the developed acrylic viscosity agent on the physical properties of concrete evaluated. The amount acrylic viscosity agent used was 0.28%, 0.29% and 0.30% based on the binder amount of 350kg/m³, and slump flow test, air volume measurement, U-Box passing test and strength compressive were conducted to determine the effect of the physical properties of concrete. it was judged that 0.29% of the cellulose type viscosity agent used in high-fluidity concrete using low-binder was most suitable.