Sulfuric acid degradation of alkali-activated metakaolin cements supplemented with brucite
نویسندگان
چکیده
This study investigated the effect of alkali content (Na:Al = 0.86 and 1.39) brucite (i.e., Mg(OH)2) mineral addition on sulfuric acid resistance alkali-activated metakaolin geopolymers). Geopolymers consist primarily a sodium-stabilized aluminosilicate hydrate (N-A-S-H) framework. Results demonstrate that higher contents improve N-A-S-H, as evidenced by reduced dealumination Si Na leaching upon exposure to acid. These results are mechanistically explained increased retention Mg+2 within microstructure Mg–Al interaction exposure. Higher coupling together provide empirical evidence polyvalent cationic stabilization—a mechanism involving cations (e.g., Mg+2) stabilize N-A-S-H binder arresting acid-induced electrophilic attack. further illustrate addition, especially at high-alkali formulations, reduces micro-scale porosity while increasing proportion gel pores (<5 nm), which suggests tortuosity may aid in promote observed herein.
منابع مشابه
Preparation and Properties of Alkali Activated Metakaolin-Based Geopolymer
The effective activation and utilization of metakaolin as an alkali activated geopolymer precursor and its use in concrete surface protection is of great interest. In this paper, the formula of alkali activated metakaolin-based geopolymers was studied using an orthogonal experimental design. It was found that the optimal geopolymer was prepared with metakaolin, sodium hydroxide, sodium silicate...
متن کاملEffects of Nano-SiO2 on Setting Time and Compressive Strength of Alkali- activated Metakaolin-based Geopolymer
This study presents a discussion on the effects of different solid-to-liquid (S/L) ratios (0.97 to 1.19) and nanoSiO2 (NS) percentages (0% to 3%) on some properties of metakaolin (MK)-based geopolymers. The setting time and compressive strength were investigated. Mercury intrusion porosimetry, fourier transform infrared spectroscopy, and scanning electron microscopy were used to determine the m...
متن کاملInvestigation on the effect of slag and limestone powder addition in alkali activated metakaolin
Alkali activated material has recently attracted great attention as an environmentally friendly building material. Generally, it exhibits higher mechanical properties and better durability when compared with Portland cement based materials. In this article, mixed alkali activated systems consisting of N-A-S-H and C-A-S-H hydrated gels were produced, using metakaolin as a dominated starting mate...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
ژورنال
عنوان ژورنال: Cement & Concrete Composites
سال: 2021
ISSN: ['0958-9465', '1873-393X']
DOI: https://doi.org/10.1016/j.cemconcomp.2021.104063