In this study, different amounts of SiO₂ nanoparticles (7 nm) were added to simultaneously reach high transmittance, high hardness, and high adhesion for TiO₂ film prepared by the sol–gel method and coated on glass through a dip-coating technique. For the film to achieve self-cleaning, anti-fogging, superhydrophilicity, and visible photo-induced photocatalysis, TiO₂-SiO₂ film was modified via a rapid microwave plasma-nitridation process for efficient N-doping by various N₂-containing gases (N₂, N₂/Ar/O₂, N₂/Ar). Through nitrogen plasma, the content of N atom reached 1.3% with the ratio of O/Ti atom being 2.04. The surface of the thin films was smooth, homogeneous, and did not crack, demonstrated by the root mean square (RMS) roughness of film surface being 3.29–3.94 nm. In addition, the films were composed of nanoparticles smaller than 10 nm, with a thickness of about 100 nm, as well as the crystal phase of the thin film being anatase. After the plasma-nitridation process, the visible-light transmittance of N-doped TiO₂-SiO₂ films was 89.7% (clean glass = 90.1%). Moreover, the anti-fogging ability was excellent (contact angle < 5°) even without light irradiation. The degradation of methylene blue showed that the photocatalytic performance of N-doped TiO₂-SiO₂ films was apparently superior to that of unmodified films under visible-light irradiation. Moreover, the pencil hardness and adhesion rating test of the thin films were 7H and 5B, respectively, indicating that the obtained coatings had great mechanical stability.

Wastes can be effectively used in concrete and the characteristics of concrete can be maintained or enhanced, the economy of waste management can be greatly increased, and the pollution of the earth can be reduced. This study aimed to research the durability of cement mortar prepared using different W/B ratios and different percentages of waste PE content. The cement mortar was mixed with 0%, 1%, 2%, 3%, and 4% waste PE and 20% ground-granulated blast-furnace slag (GGBFS) in W/B ratios of 0.4, 0.5, and 0.6. The results sw that the slump and flow decrease as the waste PE content is increased and increase with increasing W/B ratio, and the setting time is shortened as the waste PE content is increased. In terms of hardened properties, the specimen strength is slightly decreased as the waste PE content is increased, but the hardened properties are better at a later age due to the pozzolanic reaction of slag, which can be verified by microscopic SEM.

This study presents an innovative approach for the utilization of industrial by-products and municipal waste in the production of sustainable and environmentally friendly cement mortar. We explored stabilized stainless-steel reduced slag (SSRS) and polyethylene (PE) plastic waste as partial replacements for aggregates. Various engineering properties of the resulting cement mortar specimens, including the slump, slump flow, compressive strength, flexural strength, tensile strength, water absorption, and ultrasonic pulse velocity (UPV), were investigated through comprehensive experimental tests. The influence of different water–cement (w/c) or water–binder (w/b) ratios and substitution amounts on the engineering properties of the cement mortar samples was thoroughly examined. The findings revealed that an increase in PE substitution adversely affected the overall workability of the cement mortar mixtures, whereas an increase in the SSRS amount contributed to enhanced workability. As for the hardened properties, a consistent trend was observed in both cases, with higher w/c or w/b ratios and substitution amounts leading to reduced mechanical properties. Water absorption and UPV test results validated the increased formation of porosity with higher w/c or w/b ratios and substitution amounts. This study proposes a promising method to effectively repurpose industrial by-products and municipal waste, transforming them into sustainable construction and building materials. Additionally, a comparative analysis of the transportation costs and carbon footprint emissions between SSRS–cement mortar and PE–cement mortar was conducted to assess their environmental impact and sustainability. Generally, higher w/c or w/b ratios and replacement levels corresponded with a reduced carbon footprint. The geographical location of the source of SSRS and PE remains a challenge and studies to overcome this challenge must be further explored.

This study presents an innovative approach for the utilization of industrial by-products and municipal waste in the production of sustainable and environmentally friendly cement mortar. We explored stabilized stainless-steel reduced slag (SSRS) and polyethylene (PE) plastic waste as partial replacements for aggregates. Various engineering properties of the resulting cement mortar specimens, including slump, slump flow, compressive strength, flexural strength, tensile strength, water absorption, and ultrasonic pulse velocity (UPV), were investigated through comprehensive experimental tests. The influence of different water-cement (w/c) ratios and substitution amounts on the engineering properties of the cement mortar samples was thoroughly examined. The findings revealed that an increase in PE substitution adversely affected the overall workability of the cement mortar mixtures, whereas an increase in SSRS amount contributed to enhanced workability. As for the hardened properties, a consistent trend was observed for both cases, with higher w/c ratios and substitution amounts leading to reduced mechanical properties. Water absorption and UPV test results validated the increased formation of porosity with higher w/c ratios and substitution amounts. This study proposes a promising method to effectively repurpose industrial by-products and municipal wastes, transforming them into sustainable construction and building materials. Additionally, a comparative analysis of transportation costs and carbon footprint emissions between SSRS-cement mortar and PE-cement mortar was conducted to assess their environmental impact and sustainability. Generally, higher w/c ratios and replacement levels corresponded to reduced carbon footprint. The geographical location of the source of SSRS and PE remains a challenge and studies to overcome this challenge must be further explored.

This study explores the potential of using stainless steel slag, an industrial by-product of the stainless steel refining process, as a substitute for cement in concrete to promote material reuse and ecological sustainability. The research involves preparing concrete a cylindrical specimen with varying levels of substitution, ranging from 0 to 20%, and curing them for different ages (1, 3, 7, 28, and 56 days) to evaluate the engineering durability of the resulting stainless steel reducing slag concrete (SSRSC). The study found that the compressive strength of the SSRSC at 28 days was 27.44 MPa, with a splitting strength ranging from 12.81 MPa to 15.34 MPa. As the substitution amount increased, the strength decreased, but there was a positive correlation between the compressive and splitting strength. The ultrasonic wave velocity growth also increased with each substitution amount, showing that the compactness and growth of the samples improved. The surface resistance of all the samples was lower than 20 kΩ-cm, indicating that the porosity and change in porosity caused by substitution were minimal. Regarding durability, the study found that high-temperature fire damage at 200 °C catalyzed the quality, compressive strength, and resistance, but the ultrasonic wave velocity decreased. After fire damage at 600 °C and 800 °C, the compressive strength of the samples decreased by 48–57% and 76–85%, respectively, indicating that higher temperatures have a greater effect on concrete and resistance to early aging. In terms of sulfate corrosion resistance, a higher substitution amount reduced the likelihood of spalling during the early stages of the cycle, and the cumulative weight after the fifth cycle was higher than that of the control group. The autoclave expansion test revealed that the later curing age of the sample, the greater the expansion and the amount of substitution. The porosity of the samples also increased with higher temperatures and substitution amounts.

There was an error in the original publication