• Journal of the Korea Institute of Building Construction
• /
• v.12 no.1
• /
• pp.54-63
• /
• 2012

The purpose of this study is to examine the potential for reducing the environmental load and $CO_2$ gas when cement is produced by using cement substitutes. These substitutes consisted of blast furnace slag, red mud and silica fume, which were industrial by-products. The most optimum mix was derived when alkali accelerator was added to low carbon inorganic composite mixed with industrial by-product at room temperature. It is determined that hardened properties and the results of compressive strength tests changed based on CaO content, Si/Al, the mixing ratio and the amount of alkali accelerator, curing conditions and W/B. The results of test analysis suggest that the optimum mix of low carbon inorganic composite is CaO content 30%, Si/Al 4, the mixed ratio of alkali accelerator $(NaOH:Na_2SiO_3)$ 50g:50g, the amount of alkali accelerator 100g and W/B 31%. In addition, if contraction is complemented, low carbon inorganic composite with superior performance could be developed.

• Cement Symposium
• /
• no.29
• /
• pp.82-87
• /
• 2002

• Cement Symposium
• /
• no.22
• /
• pp.71-76
• /
• 1994

• Journal of the Korea Institute of Building Construction
• /
• v.13 no.6
• /
• pp.602-608
• /
• 2013

The aim of this study is to investigate experimentally the effect of the combination of fine particle cement with high Blaine fineness (FC) and recycled aggregates on the engineering properties and micro structure of high volume blast furnace slag (BS) concrete with 75% BS and 21 MPa. FC manufactured by particle classification at the plant with Blaine fineness of more than $7000cm^2/g$ was used as additional alkali activator for high volume blast furnace slag concrete made with recycled fine and coarse aggregates. FC was replaced by 15, 20 and 25% OPC. Test results showed that the incorporation of FC resulted in an increase in the compressive strength compared to BS concrete without FC by as much as 30% due to accelerated hydration and associated latent hydraulic reaction. It was found that the use of FC and recycled aggregates played an important role in activating BS for high volume BS concrete by offering sufficient alkali.

• Journal of the Korea Institute of Building Construction
• /
• v.17 no.6
• /
• pp.527-534
• /
• 2017

Accordingly, this study, in order to use powder of recycled aggregate from production of recycled aggregate as an activator of ground granulated blast furnace slag, the influence of added recycled aggregate powder on physical properties of concrete induced ground granulated blast furnace slag were analyzed by hydration stages. The results of the study are summarized as follows: Except for samples eluted powder of recycled aggregate 1%, all the samples were high alkali suspensions with higher than pH 12.0. In particular, when eluted time was 5 hours, the sample eluted powder of recycled aggregate 3% showed about 15 mg/l of calcium hydroxide that was not different from the amount of calcium hydroxide in the mixing water eluted powder of recycled aggregate 5%. Hence, from this results, it can be considered that optimal eluted powder of recycled aggregate was 3% in this study. When using mixing water eluted with powder of recycled aggregate, compared to use of ordinary mixing water, it showed greater compressive strength in the entire ages, and in the sample replaced with ground granulated blast furnace slag by 50%, its compressive strength was greater than that of the OPC. As use of mixing water eluted with powder of recycled aggregate in concrete used with large amount of ground granulated blast furnace slag was more effective for improving compressive strength than ordinary mixing water, it is verified that powder of recycled aggregate had an effect of activator.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2010.05a
• /
• pp.89-90
• /
• 2010

As a result of physical characteristics of using meta-kaolin and alkali accelerator, it was found that higher curing temperature density is favorable to strength development at early age and the higher the age is, the higher, most of the compressive strength gets. Also, I was shown that more than atmospheric curing, steam curing was favorable for development of compressive strength. When the temperature of curing temperature was higher, most of the compressive strengths were higher. Thus, based on this study, it was understood that environmental-friendly chemically combined concrete using meta-kaolin and alkali accelerator can be utilized without using cement.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2011.11a
• /
• pp.217-218
• /
• 2011

The advantages of blast-furnace slag concrete may include lower hydration heating velocity, restraint on concrete temperature increase, long-age strength improvement due to latent hydraulic reaction, improved water tightness, and repulsion to chemical erosion. These advantages contribute to the high quality of the blast-furnace slag concrete. However, the blast-furnace slag concrete has its limitations as well. These disadvantages may include retarded setting and elongated retention of mold due to the weak strength of early-age. Nevertheless, much research is currently under way to improve the aforementioned issues. To improve activity of blast furnace slag powder, alkaline irritants has been used. In this study, we analyze effect on activity fineness and rate of substitution of Alkali Activator toward activity.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2016.10a
• /
• pp.32-33
• /
• 2016

This purpose of this study is to find the properties of pore structure and length change of blast furnace slag cement added alkali powder stimulant on shrinkage reducing agent presence. In length change, the specimen added alkaline stimulant was smaller than normal blast furnace slag concrete. And the specimen added shrinkage reduction agent was confirmed to show smaller rate of length change than the length. In MIP analysis of 1day-age, 0.1㎛ subsequent pore amount of the specimen added alkaline stimulant was significantly smaller value the normal blast furnace slag concrete specimen.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.05a
• /
• pp.173-174
• /
• 2017

Recently, many experiments using industrial by-products have been going on in Korea and abroad. Most of the studies on blast furnace slag and fly ash have been conducted, and the blast furnace slag based two and three component experiments have been conducted in many places. Therefore, this study is an additional study of research using polysilicon sludge and paper ash, which is a study using existing industrial by-products based on blast furnace slag, as strength properties of alkali activator according to kind and mixing ratio and to obtain basic data do.

• Proceedings of the Korean Institute of Building Construction Conference
• /
• 2017.11a
• /
• pp.161-162
• /
• 2017

As the use of cement increases with the development of modern society along with the increase of buildings, environmental pollution intensifies and researches on industrial byproducts are continuing. Research on blast furnace slag and fly ash as industrial byproducts is increasing, and research on industrial byproducts such as polysilicon sludge and paper ash used in this study is increasing. Blast furnace slag, which is one of the industrial byproducts, has been widely studied as a material used with cement. However, in this study, we fabricated lightweight matrix of polysilicon sludge and paper ash replaced based on blast furnace slag, and performed SEM analysis.