• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2003년도 봄 학술발표회 논문집
• /
• pp.271-276
• /
• 2003

This study is about the rheological properties of cement slurry using admixtures. The variables are the type of cement(Type I, II, IV, V) and the substitution ratio of admixtures such as fly ash and slag. As a result of measuring the fluidity of various types of cement slurry at the early stage, type 2, type 4 and type 5 showed the similar property. The fluidity of type 1 and ternary blended cement was low. it is thought that it is because of the high $C_3$A content. The cement slurries containing mineral admixtures were superior in the property of fluidity retention.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2019년도 춘계 학술논문 발표대회
• /
• pp.205-206
• /
• 2019

This study investigated the fluidity and compressive strength properties of blast furnace slag based non-cement paste containing ferronickel slag powder to evaluate the possibility of use in for cement replacement materials. As a result, the fluidity of non-cement paste showed a higher flow as the mixing ratio of ferronickel slag powder increased. The compressive strengths similar to those of the non-cement paste using only blast furnace slag powder were obtained when 5 and 10% of ferronickel slag powder were used.

• Computers and Concrete
• /
• 제11권6호
• /
• pp.531-539
• /
• 2013

An experimental investigation of mechanical properties of jute fiber-reinforced concrete (JFRC) has been reported for making a suitable construction material in terms of fiber reinforcement. Two jute fiber reinforced concretes, called jute fiber reinforced normal strength concrete (JFRNSC) and jute fiber-reinforced high-fluidity concrete (JFRHFC), were tested in compression, flexure and splitting tension. Compressive, flexural and splitting tensile strengths of specimens were investigated to four levels of jute fiber contents by volume fraction. From the test results, Jute fiber can be successfully used for normal strength concrete (NSC) and high-fluidity concrete (HFC). Particularly, HFC with jute fibers shows relatively higher improvement of strength property than that of normal strength concrete.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2006년도 추계 학술발표회 논문집
• /
• pp.949-952
• /
• 2006

An understanding of rheological property on cement paste is one of the important factor to design concrete such as High-fluidity Concrete (HFC) for a specific application. The HFC is a specially proportioned hydraulic cement concrete that enables the fresh concrete to flow easily into the forms and around the reinforcement and prestressing steel without vibration and segregation. Use of this type of concrete for the concrete building construction, manufacture of precast, prestressed bridge elements provides the benefits of increased rate of production and safety, reduced labor needs, and lower noise levels. This paper presents the performance of rheological properties of cement paste incorporating domestic high-water-reduced-admixture (HWRA) for an Ultra-high-fluidity concrete (UHFC). Investigation was carried out on cement pastes with combinations of various dosages of HWRA and water/cement ratios.

• 콘크리트학회논문집
• /
• 제12권4호
• /
• pp.49-58
• /
• 2000

There are many methods to improve the performance of concrete. Especially, granuated blast furnace slag. by-products used in concrete as the replacement material of cement, could contribute to improve the fluidity, resistance of chemical attack and strength of concrete. Also, it could contribute to decrease the rate of generating hydration heat, in addition to cost-down of concrete and prevention of enviromental pollution. Therefore, in order to establish the systemical application of granuated blast furnace slag in normal concrete, the engineering properties of concrete, such as fluidity, strength, setting and hydration properties etc.. was evaluated. In this study, replacement ratio of granuated blast furnace slag was 0, 30, 50, 70(%), and target slump was 8, 12, 15, 18(cm). Results from the experiment, granuated blast furnace slag showed the outstanding effects of improving the engineering properties of concrete. From now on, positive application of granuated blast furnace slag is expected in the point of improving the performance and cost-down of concrete.

• Advances in nano research
• /
• 제13권1호
• /
• pp.13-28
• /
• 2022

The pumpability of the grouts is significant issue in concept of the rheological and workability properties during penetrating to voids and cracks. To improve the fluidity features of the grout mixes, the usage of Colloidal Nano Particular Powders (CNPPs) with mineral additives such as fly ash (FA) can contribute. Therefore, the main purpose of this study can be explained as investigating the usage effects of four types of Colloidal Nano Particular Powders (n-TiO₂, n-ZnO, n-Al₂O₃ and n-SiO₂) as nano additives on the rheological, workability and bleeding properties of cement-based grout incorporated with fly as. Test results showed that the usage of FA in the grout samples positively contribute to increase on the fluidity of the grout samples as expected. The dilatant behavior was observed from the results for all mixes. Observing the effect of nano-sized additives in such cement-based grout mixtures with high fluidity has presented remarkable effects in this study.

• 한국건설순환자원학회논문집
• /
• 제10권4호
• /
• pp.506-513
• /
• 2022

본 논문에서는 탄소중립을 위한 일환의 연구로써 3가지의 산업부산물을 활용하여 시멘트 사용량에 대하여 80 %까지 대폭 대체한 4성분계 고유동 콘크리트의 품질특성을 평가하였다. 평가결과, 다량의 산업부산물을 혼합하여 시멘트 사용량을 80% 이상 감소시킨 배합에서 목표 성능을 만족하는 품질을 얻을 수 있었으며, 유동특성, 역학특성 및 내구특성의 경우 기존 기준 배합과 비교하여 다소 성능이 감소되는 경향이 나타났지만 소요성능 수준 이상의 성능을 만족할 수 있는 것으로 판단된다. 종합적으로 고려할 경우 고로슬래그 미분말 혼합량이 큰 4성분계 고유동 콘크리트가 상대적으로 우수한 성능을 보였다.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2015년도 추계 학술논문 발표대회
• /
• pp.51-52
• /
• 2015

In this study, the concrete in which the hybrid fiber with different volume and rate was intermixed in high fluidity concrete. However, Fiber Ball is frequently caused by the decrease in the dispersion of the fiber. The research has been conducted primarily study of single fiber or hybrid fiber, such as different length of single fiber. Therefore, we investigate the mechanical properties of concrete was mixed with a combination of various fibers been produced domestically. Its purpose being to provide basic data for evaluating the impact hybrid fibers on the fluidity of concrete.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2001년도 봄 학술발표회 논문집
• /
• pp.641-646
• /
• 2001

Generally, when Fly-Ash was used as replacement material of cement in concrete, it might occur retardation of setting and hardening. So, it is unable to use a large amount of Fly-Ash as replacement for cement. However, if it is used as replacement material of fine aggregate in concrete, we can use a large amount of Fly-Ash and settle a problem of natural-aggregate exhaustion. Furthermore, engineering properties of High Volume Fly-Ash Concrete Is better than that of plain concrete But, the larger Fly-Ash is replaced, the more fluidity of High Volume Fly-Ash Concrete decrease, because porous organization of Fly-Ash adsorb water and Superplasticizer. In this study, after appending additional water to High Volume Fly-Ash Concrete in proportion to weight of Fly-Ash, we intend to find proper ratio which doesn't affect strength and satisfy fluidity As a result of this study, it was found that fluidity of mortar with 25~28 percentage of additional water was satisfied with fluidity of plain mortar, and compressive strength of that was similar to plain mortar's

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2004년도 춘계 학술발표회 제16권1호
• /
• pp.312-315
• /
• 2004

The effects of polymer-cement ratio, antifoamer content and shrinkage-reducing agent content on the strength of high-fluidity polymer-modified mortars using redispersible polymer powder are examined. As a result, the flexural and tensile strengths of the high-fluidity polymer-modified mortars using redispersible polymer powder tend to increase with increasing polymer-cement ratio, and tend to decrease with increasing shrinkage-reducing agent content, regardless of the antifoamer content. However, the compressive strength of the high-fluidity polymer-modified mortars using redispersible polymer powder decrease with increasing polymer-cement ratio and shrinkage-reducing agent content.