• Journal of the Korea Institute of Building Construction
• /
• v.10 no.6
• /
• pp.61-66
• /
• 2010

As global warming has had harmful effects on the environment, the construction industry has made efforts to reduce the amount of $CO_2$ generated in the process of cement production. There is an urgent need for an alternative material that can replace cement. To improve the initial strength and economical efficiency pointed out as problems, this research was conducted for Blast Furnace Slag (BFS), an industrial byproduct. Non-sintering cement (NSC) was used by minimizing the amount of high-priced alkali activators. By using Nano-technology, fineness has been maximized, to enhance the initial strength of BFS. This research is based on non-sintered cement replaced by nano-slag using alkali activators, and the fundamental properties and quality of the non-sintered cement were investigated. A variety of activators were used, up to 10 percent of the slag weight. This research aims to present fundamental data through a comparative analysis of flexural strength, compressive strength, time of setting, diabetic temperature, and rising heat.

• Journal of the Korea Institute of Building Construction
• /
• v.23 no.4
• /
• pp.359-367
• /
• 2023

This experimental study investigates the replacement of conventional Portland cement and sand with non-sintered cement and ferro-nickel slag to formulate eco-friendly cement mortar. The examination aimed to understand the strength properties of non-sintered cement mortar using ferro-nickel slag as fine aggregate by classifying mortar production types, fine aggregates, and curing methodologies. From flexural and compressive strength tests, it was observed that non-sintered cement mortars, incorporating ferro-nickel slag as fine aggregate, exhibited superior strength when compared to both plain mortar and steam-cured non-sintered mortar. This increased strength is attributed to the influence of the particle size, density, and absorption capabilities of the ferro-nickel slag. Furthermore, X-ray Diffraction(XRD) analyses of the mortars verified the presence of MgO, a component of ferro-nickel slag, in the form of a composite oxide. This finding substantiates the consistent strength manifestation of non-sintered cement mortars utilizing ferro-nickel slag as a fine aggregate.

• Journal of the Korea Institute of Building Construction
• /
• v.22 no.5
• /
• pp.441-450
• /
• 2022

In this study, the fluidity and strength characteristics of NSC mortar according to the type and rate of addition of superplasticizer were analyzed to secure the fluidity of NSC composed of only slag and ash. Through the flow test, it was found that the fluidity of NSC was related to the basicity according to the binder condition, and the lower the reactivity, the higher the fluidity. When polycarboxylate is added, NSC mortar is considered to be more advantageous than plain mortar in terms of securing fluidity. As a result of the strength tests of NSC mortar containing Lignin or Polycarboxylate superplasticizer, it was found that the strength tends to increase as the basicity increases. In addition, when polycarboxylate is added, it is judged that the NSC mortar can secure adequate fluidity and strength at the same time. Through this experiment, an appropriate binder condition that satisfies the flowability while securing the strength was derived.

• Journal of the Korea Institute of Building Construction
• /
• v.12 no.1
• /
• pp.115-121
• /
• 2012

If cement could be manufactured with industrial byproducts such as granulated blast furnace slag, phosphogypsum, and waste lime rather than clinker, there would be many advantages, including the maximization of the use of these industrial byproducts for high value-added resources, the conservation of natural resources and energy by omitting the use of clinker, the minimization of environmental pollution problems caused by $CO_2$ discharge, and the reduction of the production cost. For this reason, in this study, mechanical behavior tests of non-sintered cement concrete were performed, and elasticity modulus and stress-strain relationship of non-sintered cement concrete were proposed. Nine test members were manufactured and tested according to reinforcement ratio and concrete compressive strength. According to the test results, there was no difference between general cement concrete and non-sintered cement concrete in terms of flexure and shear behavior.

• Journal of the Korea Institute of Building Construction
• /
• v.21 no.2
• /
• pp.97-104
• /
• 2021

This study aims to develop non-sintered cement that can replace the Portland cement by utilizing industrial by-products. As a suggestion, the physical properties of non-sintered cement mortar depending on the curing method were investigated with ground granulated blast furnace slag, class C fly ash, and class F fly ash. As a result of the study, it was found that the strength performance and absorption rate were improved through the heat treatment process after steam curing. It was confirmed through crystal phase analysis that the hydration was accelerated after heat treatment, and the bonding material formed a dense internal structure.

• Journal of the Korea Institute of Building Construction
• /
• v.20 no.1
• /
• pp.19-26
• /
• 2020

This study aimed to develop non-sintered cement that could replace portland cement which emits large amount of carbon dioxide during firing process. For this purpose, ground granulated blast furnace slag, type c fly ash and slaked lime were used. In addition, through the experimental results, the characteristics of the non-sintered cement binders according to the mixing ratios will be identified, and the utilization plans for the precast concrete products will be presented. In this experiment, non-sintered cement binders using industrial by-products were prepared to compare the flexural strength and compressive strength of each of the 3, 7 and 28 days. As a result, the results satisfy the KS of the target product proposed in this study. Therefore, this study presents the possibility of using precast concrete products by developing non-sintered cement binders using industrial by-products.

• Journal of the Korea Institute of Building Construction
• /
• v.22 no.6
• /
• pp.641-649
• /
• 2022

This study aims to completely develop a non sintered cement mortar using industrial by-products. To replace Portland cement, blast furnace slag, circulating fluidized bed fly ash, and pulverized coal fly ash were used, and natural aggregates were substituted with ferronickel slag. To understand the characteristics of the non sintered cement mortar to which ferronickel slag is applied, an experiment was conducted by classifying the particle size. Fluidity and workability were confirmed through the flow test, and bending and compressive strength tests were conducted at 3, 7, and 28 days of age. In addition, durability was identified through a chloride ion penetration test. Through the study, it is judged that the binder, which completely replaced cement and aggregate, has high potential of being used as a construction material. Notably, it was confirmed to be advantageous for strength and durability.

• Journal of the Korea Concrete Institute
• /
• v.27 no.3
• /
• pp.245-252
• /
• 2015

As people have more interest in environment-friendly structures recently, many researchers are actively researching non-sintered cement in Korea and other countries. Non-sintered cement shows various characteristics of its reaction products and hardeners, depending on the kind of alkali activators. Thus, this study manufactures ground granulated blast furnace slag based non-sintered cement binder by using circulating fluidized bed combustion ash, which is a kind of industrial byproduct, as a stimulant, and investigated its hardening characteristics and hydration, depending on the rate of circulating fluidized bed combustion ash. Besides, this study investigated its insulation property according to the weight lightening of non-sintered cement. As a result, ettringite and C-S-H were mainly formed in the hydration, and it was possible to manufacture a non-sintered cement hardener over 50 MPa. Lastly, it was possible to manufacture a non-sintered cement hardener in a thermal conductivity level of $0.127W/m{\cdot}K$ when the compressive strength was 10 MPa for weight lightening.

• Korean Journal of Mineralogy and Petrology
• /
• v.35 no.1
• /
• pp.25-39
• /
• 2022

This study was conducted to evaluate the manufacturing process of non-sintered cement for the safe containment of radioactive waste using low level or ultra-low level radioactive waste soil generated from nuclear-decommissioning facilities, clay minerals, and blast furnace slag (BFS) as an industrial by-product recycling and to characterize the products using mineralogical and morphological analyses. A stepwise approach was used: (1) measuring properties of source materials (reactants), such as waste soil, clay minerals, and BFS, (2) manufacturing the non-sintered cement for the containment of radioactive waste using source materials and deducing the optimal mixing ratio of solidifying and adjusting agents, and (3) conducting mineralogical and morphological analyses of products from the hydration reactions of manufactured non-sintered cement solidifier (NSCS) containing waste concrete generated from nuclear-decommissioning facilities. The analytical results of NSCS using waste soil and clay minerals confirmed none of the hydration products, but calcium silicate (CSH) and ettringite were examined as hydration products in the case of using BFS. The compressive strength of NSCS manufactured with the optimum mixing ratio and using waste soil and clay minerals was 3 MPa after the 28-day curing period, and it was not satisfied with the acceptance criteria (3.44 MPa) for being brought in disposal sites. However, the compressive strength of NSCS using BFS was estimated to be satisfied with the acceptance criteria, despite manufacturing conditions, and it was maximized to 27 MPa at the optimal mixing ratio. The results indicate that the most relevant NSCS for the safe containment of radioactive waste can be manufactured using BFS as solidifying agent and using waste soil and clay minerals as adsorbents for radioactive nuclides.

• Cement
• /
• s.192
• /
• pp.39-47
• /
• 2011

최근 온실가스 감축과 기후변화 그리고 녹색성장에 대한 관심증대와 더불어 시멘트 분야의 연구 생산분야는 천연자원 사용량을 줄이고, 소성공정을 도입하지 않은 새로운 개념의 무기바인더가 다시 고개를 들고 있다. 다른 용어로는 비소성, 무시멘트 등으로 표현되기도 하는데, 광의의 개념으로 보면 알칼리 활성화제를 사용한 비소성 무기결합재인 지오폴리머가 바로 그것이다. 지오폴리머 결합재는 1957년 우크라이나의 토목공학회에서 개발한 알칼리 활성 슬래그시멘트에 기원을 두고 있고, 1970년대 말 프랑스의 다비도비치에 의해 지오폴리머라는 용어가 처음 사용되기 시작했다. 알칼리 활성 무기결합재(Alkali-activated inorganic binder)의 정의이다. Alkali-activated inorganic binder는 원래는 결합능력이 없던 재료에 대해서 Alkali-activating 용액을 첨가했을 때, 시멘트처럼 결합능력을 가지게 되는 모든 종류의 결합시스템을 말한다. 국내에도 이미 2000년 초부터 지오폴리머의 개념을 도입한 제품이 상업화되어 오랫동안 품질검증을 거쳐 안정성이 확인되고 있다. 최근에 다시 전남대가 그 동안의 연구성과를 발 빠르게 중소기업에 기술 이전하여 소위 무시멘트 시대에 진입하는 분위기이다. 지난 9월 동아에스텍(주)과 조인트벤처 설립을 위해 손을 잡았고, 사업화가 곧 진행될 것으로 보인다. 이를 계기로 국내에도 무시멘트회사가 본격적으로 등장하게 된 것이다. 따라서 본 고는 무시멘트의 개념을 잘 표현한 문헌으로 일본콘크리트공학 연차논문집, 2010년 1월호를 번역 요약 발췌한 것이다.