Utilization of Industrial Waste Slags to Enhance Ground Waste Concrete-Based Inorganic Polymers
- PDF / 2,540,029 Bytes
- 17 Pages / 595.276 x 790.866 pts Page_size
- 23 Downloads / 141 Views
RESEARCH ARTICLE
Utilization of Industrial Waste Slags to Enhance Ground Waste Concrete‑Based Inorganic Polymers Aikaterini Ioannis Vavouraki1
© The Minerals, Metals & Materials Society 2020
Abstract Recycling and utilization of waste concrete and industrial waste slags is a significant step towards the protection of the environment and sustainable development. Industrial waste slags including ferronickel (Greece) and fayalite (Finland) slags were mixed with ground waste concrete for the production of inorganic polymers (IPs). The effects of different parameters during alkaline activation such as solution concentration (6 to 12 M NaOH), curing temperature (60 to 80 °C), and aging period (7 to 28 days) upon the uniaxial compressive strength of the produced specimens were determined. The optimum conditions for ground concrete waste-based inorganic polymers were found to be the use of alkali activator with mass ratio of Na2SiO3 to NaOH 1 and L/S 0.3 cured at 80 °C for 24 h and aged for 7 days with compressive strength of 16 MPa. Molar SiO H2 O ratios of Al O2 and Na O+K in the reactive paste were 16.03 and 13.02, respectively. IPs produced from ground concrete waste O 2
3
2
2
(GWC), fayalitic (FS), and ferronickel (LS) slag mixtures; in particular, a mix ratio of 25GWC-25FS-50LS ( Na2SiO3 to NaOH 1 and L/S 0.2, cured at 60 °C for 24 h and aged for 7 days) obtained high compressive strength (47 MPa). Molar ratios SiO H2 O of Al O2 and Na O+K in the reactive paste were 9.59 and 16.81, respectively. Structural integrity of selected IPs (25GWCO 2
3
2
2
25FS-50LS) was observed when immersed in acidic H 2SO4 and salt N a2SO4 solutions of 0.5 M and/or subjected to hightemperature firing (up to 400 °C). Graphical Abstract
The contributing editor for this article was João António Labrincha Batista. Electronic supplementary material The online version of this article (https://doi.org/10.1007/s40831-020-00281-8) contains supplementary material, which is available to authorized users. Extended author information available on the last page of the article
13
Vol.:(0123456789)
Journal of Sustainable Metallurgy
Keywords Inorganic polymers · Ground waste concrete · Fayalitic slag · Ferronickel slag · Durability tests
Introduction Concrete is the second most widely used substance after water around the globe. Concrete is a composite material consisting of binding materials (i.e., Portland cement, lime) mixed with aggregates (i.e., sand, gravel) and/or chemical or mineral admixtures (i.e., fly ash) [1] in water in specific proportions. Due to its large volume utilization in countless construction works from tower blocks to car parks, cement production has considerable increased in the last years contributing 5% of annual anthropogenic global C O2 production. The high range of concrete applicability indirectly related to millions of tons of waste concrete generation every year around the world due to different reasons such as demolition and destruction of old structures and buildings due to natural caus
Data Loading...
