KR-20260066493-A - CALCIUM SILICATE CEMENT COMPOSITION COMPRISING ADDITIVE FOR INTERNAL CARBONATION AND CONCRETE COMPOSITION COMPRISING THE SAME

Abstract

The present invention relates to a cement composition for a concrete binder comprising calcium silicate cement (CSC) and an additive for internal carbonation selected from sodium carbonate ( Na₂CO₃ ) and sodium bicarbonate ( NaHCO₃ ), and a concrete composition comprising said cement composition.

Inventors

• 박솔뫼
• 베르시사, 구디사 아마누엘
• 김영선
• 전현수
• 이상현
• 기전도
• 박상현
• 석원균

Assignees

• 국립부경대학교 산학협력단
• 롯데건설 주식회사

Dates

Publication Date

20260512

Application Date

20241104

Claims (5)

1. Calcium silicate cement (CSC); and Additives for internal carbonation selected from sodium carbonate ( Na₂CO₃ ) and sodium bicarbonate ( NaHCO₃ ) . Cement composition for concrete binders.
2. In paragraph 1, For 100 parts by weight of calcium silicate cement (CSC), Characterized by containing 2.5 to 10 parts by weight of sodium carbonate ( Na₂CO₃ ) . Cement composition for concrete binders.
3. In paragraph 1, For 100 parts by weight of calcium silicate cement (CSC), Characterized by containing 2.5 to 10 parts by weight of sodium bicarbonate ( NaHCO₃ ). Cement composition for concrete binders.
4. In paragraph 1, Calcium silicate cement (CSC) is characterized by comprising CS(CaO· SiO2 ), C3S2 (3CaO· 2SiO2 ), C2S (2CaO· SiO2 ), unreacted CaO (Free-CaO), and an amorphous phase . Cement composition for concrete binders.
5. A concrete composition comprising a cement composition according to any one of paragraphs 1 to 4, fine aggregate, coarse aggregate, and water.

Description

Calcium silicate cement composition comprising an additive for internal carbonation and concrete composition comprising the same The present invention relates to a calcium silicate cementitious composition included as a binder in the manufacture of concrete and a concrete composition containing the same. Carbon dioxide ( CO2 ) emissions from the global energy sector reached 37 billion tons in 2022, an increase despite strategic efforts to achieve carbon neutrality by 2050. Accordingly, various methods to reduce carbon dioxide are being explored for each industry. In particular, the cement industry, which faces significant pressure regarding carbon dioxide emission regulations due to its production processes inevitably generating excess carbon dioxide, is striving to reduce process carbon dioxide emissions through measures such as improving energy efficiency, using low-carbon fuels, and reducing the clinker ratio. In this regard, calcium silicate cement (CSC) is expected to contribute significantly to the reduction of carbon dioxide in the construction sector, as it exhibits the characteristic of hardening through a carbonation reaction that absorbs carbon dioxide and forms a binding phase such as CaCO3 and silica gel, unlike Portland cement. However, when manufacturing a structure containing calcium silicate cement by hardening the calcium silicate cement through a carbonation reaction as described above, the penetration depth of carbon dioxide is mainly limited to the outer layer of the calcium silicate cement structure because the carbonation reaction products hinder the diffusion of carbon dioxide into the interior of the structure; this phenomenon results in heterogeneous carbonation products, which negatively affect the mechanical properties of the structure. FIGS . 1a to 1f are DTG curves of samples containing various concentrations of Na₂CO₃ and NaHCO₃ in the embodiments of the present invention (Figs. 1a and 1d: 6 hours, Figs. 1b and 1e: 24 hours, Figs. 1c and 1f: 72 hours). FIGS . 2a to 2f are XRD patterns of samples containing various concentrations of Na₂CO₃ and NaHCO₃ in the embodiments of the present invention (( FIGS. 1a and 1d: 6 hours, FIGS. 1b and 1e: 24 hours, FIGS. 1c and 1f: 72 hours; key: 1-CS, 2 -βC₂S, 3-CaCO₃, 4 -S, 5-Ca(OH) ₂ , 6 - C₃S₂ , 7 -γC₂S, 8-Free CaO and 9- Na₂CO₃ · H₂O ). Figures 3a and 3b are quantitative phase analysis results according to the concentrations of Na₂CO₃ and NaHCO₃ , respectively , of samples containing Na₂CO₃ and NaHCO₃ after 72 hours of curing in the present embodiment, and Figures 3c to 3f are quantitative phase analysis results showing the effect of curing time on internal carbonation and CO₂ cured samples. FIGS . 4a to 4f are FT-IR spectra of samples containing various concentrations of Na₂CO₃ and NaHCO₃ in the present embodiment (Figs. 4a and 4d: 6 hours, Figs. 4b and 4e: 24 hours, Figs. 4c and 4f: 72 hours). FIGS. 5a to 5d are cumulative heat curves and heat flow curves of samples containing various concentrations of Na₂CO₃ and NaHCO₃ in the present embodiment. In describing the present invention, if it is determined that a detailed description of related known functions or configurations could unnecessarily obscure the essence of the invention, such detailed description will be omitted. Since embodiments according to the concept of the present invention may be subject to various modifications and may take various forms, specific embodiments are illustrated in the drawings and described in detail in this specification or application. However, this is not intended to limit embodiments according to the concept of the present invention to specific disclosed forms, and it should be understood that they include all modifications, equivalents, and substitutions that fall within the spirit and scope of the present invention. The terms used herein are merely for describing specific embodiments and are not intended to limit the invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this specification, terms such as “comprising” or “having” are intended to specify the existence of the described features, numbers, steps, actions, components, parts, or combinations thereof, and should be understood as not precluding the existence or addition of one or more other features, numbers, steps, actions, components, parts, or combinations thereof. The present invention will be described in more detail below with reference to preferred embodiments. The presented embodiments are merely specific examples of the present invention and are not provided for the purpose of limiting the scope of the present invention. <Example> First, calcium silicate cement (CSC) clinker was prepared by mixing limestone and silica fume in a molar ratio of 1:1 CaO: SiO2 , and then calcined at 1250°C for 4 hours and ground with a jet mill to produce CSC cement. The fineness of the produced CSC cement was confirmed to be 3710 cm² /g and the dens