Sürdürülebilir Kalkınma Amaçları
Yayınlar
- MakaleAçık Erişim2026Scopus SJRQ1Freeze–Thaw Performance and Microstructural Stability of Alkali-Activated Slag Mortars Incorporating Mussel Shell Waste
Şahin Yön, Merve
This study investigates the use of mussel shells (MSs), a biogenic by-product of the food industry, as a partial replacement for ground granulated blast furnace slag (GBFS) in alkali-activated mortars. Given their high CaCO3 content, MSs represent a sustainable secondary raw material that reduces both waste disposal burden and reliance on natural resources, while offering a low-carbon alternative to conventional cement-based binders. Alkali-activated mussel shell/slag mortars (AAMSs) were produced with MS replacement ratios of 0%, 5%, 10%, 15%, and 20% by mass of GBFS. Sodium hydroxide (NaOH) and sodium silicate (Na2SiO3) were used as alkaline activators. Fresh specimens were cured at 60 °C for 48 h. The experimental program included workability, compressive and flexural strength, water absorption, porosity, density, capillarity, ultrasonic pulse velocity (UPV), and freeze–thaw (F-T) resistance tests. Increasing MS content slightly reduced flowability and mechanical strength, while increasing water absorption, porosity, and capillarity. The M0 series achieved the highest 28-day compressive strength (54.06 MPa), while M15 exhibited the highest flexural strength (5.23 MPa). Following F-T cycling, the 5% and 10% MS series demonstrated the best compressive strength (30 MPa). The 10% MS exhibits a relatively balanced overall performance, providing the best balance between mechanical performance, F-T resistance, and microstructural stability, as confirmed by scanning electron microscopy (SEM)/energy-dispersive X-ray spectroscopy (EDS) analyses showing elevated Ca/Si ratios and the formation of Ca-rich crystalline phases.
- MakaleYalnız künye2025Scopus SJRQ1Mechanical, durability and microstructure properties of eco-friendly self-compacting mortars with addition of volcanic scoria, silica fume and boron waste as cement replacement
Şahin Yön, Merve
The objective of this experimental study is to investigate the mechanical and durability performances of self-compacting mortars containing industrial waste and natural stone to develop an environmentally friendly mortar. Binary series of boron waste (B), silica fume (S) and volcanic scoria (V) were formed by substituting up to 95 % by weight with Portland cement, and ternary series were formed by substituting up to 80 % by weight with Portland cement. A total of 14 mixtures and one reference mixture (R) were improved for the purpose of investigating the workability, mechanical strength and durability properties of self-compacting mortar with different binder compositions. Samples of 40x40x160 mm were produced to evaluate mechanical properties and freeze-thaw effect, 100x100x100 mm for abrasion testing and 50x50x50 mm to determine physical properties. Additionally, SEM/EDS and XRD analyses were performed to determine the microstructural characteristics of the mixtures formed. The test results demonstrated that the sole replacement of boron waste with Portland cement resulted in enhanced fluidity. Nonetheless, the 90-day compressive strengths of the S10V20 and B5S10V5 mixtures exhibited increases of 7.47 % and 5.57 %, respectively, relative to the reference, whilst the B15 series saw a 52.5 % reduction, marking the lowest 90-day compressive strength compared to the reference sample. When the freeze-thaw effect was assessed after 136 cycles, the compressive strength diminished by 8.57 %, 13.1 %, 4.13 %, 7.28 %, 6.22 %, 24.77 %, and 48.1 % in the R, B5, V5, V10, V15, B5S10V5, B5S10V10, and B5S10V15 samples, respectively. Among the samples subjected to abrasion tests, a loss of 6.5 per thousand occurred in the mass of the reference sample at the end of 6 minutes, while a loss of 11 per thousand occurred in the binary mixture containing 5 % B, which had the highest abrasion.
AtıfScopus16WoS14OpenAlex16
İncele - MakaleYalnız künye2024Scopus SJRQ1Resistance to magnesium sulphate attack of binary and ternary cementless self-compacting alkali-activated mortar
Şahin Yön, Merve; Karataş, Mehmet
The aim of this study is to investigate the effect of sulphate on self-compacting alkali-activated mortars (SCAAMs) produced using volcanic scoria (V), boron waste (B) and granulated blast furnace slag (G) together with alkali activators. Thus, the production of cement-free alkali-active mortar by recycling waste and reducing the CO2 effect increases the importance of this study. The fact that the waste material is provided free of charge and that V is readily available from nature provides economic advantages in the production of these mortars. In this experimental study, magnesium sulphate solution was utilized to define the sulphate resistance of SCAAMs. In binary SCAAMs, B was used with G in a ratio of NS:NH = 3.0, with an increase from 5 % to 15 %; in ternary mixtures, B was used together with G and V in the same proportions, in a ratio of NS:NH = 1.0. The tests involved immersion in 5 % magnesium sulphate solution for 1, 3 and 6 months. Mass development, compressive strength, visual inspection and microstructural changes were investigated. In general, the binary SCAAMs performed better in magnesium sulphate solution than the ternary SCAAMs, except in the 6th month. Considering the samples with the highest B content, a 100 % loss of compressive strength occurred in the B15G85 sample under the influence of sulphate for 6 months, while a loss of compressive strength of about 15 % occurred in the B15G40V45 sample. The results showed that the increase in B content caused a severe deterioration of the sulphate effect in the samples over time and that the V additive had a positive effect on the sulphate resistance.
AtıfScopus26WoS23OpenAlex19İncele