Sürdürülebilir Kalkınma Amaçları
Yayınlar
- ArticleAçık Erişim2026Investigation of production and performance evaluation of high-strength lightweight concrete (HSLWC) produced with regional volcanic aggregates (RVA)
Ulusu, İsmet; Ulusu, Hayati; Gül, Rüstem
This study investigates the feasibility of producing high-strength lightweight concrete using regional volcanic aggregate (RVA) and examines the performance of the produced concrete. Various mix designs conforming to ASTM and TS EN standards were applied to achieve the targeted strength and density. The study also investigated the effect of water/cement ratio (W/C) and cement content on the mechanical and physical properties of high-strength lightweight concrete. Experimental tests such as compressive strength, tensile strength, density, water absorption, and elastic modulus were conducted to determine the effect of cement content and lightweight aggregate on the overall behavior of the concrete. To ensure adequate workability, superplasticizer was added to all mixes at a rate of 1.5% of the cement weight. The slump values of fresh concrete met modern requirements for good workability, pumpability, and high strength. The results showed that, provided a superplasticizer is used, high-strength concrete with a density range of 1830 to 1915 kg/m³ can be produced using 450 kg/m³ of cement. The results show that the porous structure and pozzolanic properties of RVA significantly increase the mechanical strength of concrete and, thanks to its porous structure, reduce its unit weight by 20–25%. The highest compressive strength recorded within 90 days for a mixture containing 650 kg/m³ of cement was 87 MPa. It was concluded that the W/C ratio and cement content have a significant effect on the mechanical and physical properties of these concretes.
RDL Kalıcı Kaydıİncele - CorrectionYalnız künye2025Corrigendum to “The usability of the brick dust and blast furnace slag in zeolite-based lime mortars in different curing environments” [Ceram. Int. 49 (2023) 4046–4054]
Çavuş, Murat; Dayı, Mustafa; Dağcı, Yunus; Ulusu, Hayati
The authors regret that this article was submitted and subsequently published as a Review article, which it should have been submitted and published as an Original Research Article. The authors would like to apologise for any inconvenience caused.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2023Mechanical, durability and microstructural characteristics of Portland pozzolan cement (PPC) produced with high volume pumice: Green, cleaner and sustainable cement development
Ulusu, Hayati; Yılmaz Aruntaş, Hüseyin; Burcu Gültekin, Arzuhan; Dayı, Mustafa; Çavuş, Murat; Kaplan, Gokhan
Nowadays, it is frequently preferred to use pozzolans instead of clinker to reduce the CO2 emissions that increase with cement production. Because in the future, the release of artificial pozzolans, such as fly ash and blast furnace slag, will decrease. Therefore, the demand for natural pozzolanic cement will increase. This study aimed to produce Portland Pozzolan Cement (PPC) by using pumice instead of clinker up to 40%. The Chemical, physical, mechanical, durability, microstructure, and carbon footprint characteristics of PPCs were investigated experimentally. As the pumice volume in the PPCs increased, the CaO/SiO2 ratio and specific gravity decreased. Due to the hygroscopic moisture of the pumice, its grindability has become difficult. While the 40 µm sieve residue of PPCs ranges from 0.8 to 1.7%, the sieve residue ratio generally increases as the pumice volume increases. The porous structure of pumice led to an increase in Blaine fineness as the replacement ratio increased. The Blaine fineness of PPCs containing 40% pumice rose by about 20% more than the reference cement. The consistency water of PCs varies between 29 and 36%. As the water consistency increased, the setting time of the pastes was prolonged. Initial setting times of PPCs are between 150 and 220 min. If the CaO/SiO2 ratio decreased with the pumice volume, the compression strength of the mortars decreased. While the 28-day compression strength of PPC containing 10% pumice was measured as 36.2 MPa, this value was measured as 21.6 MPa for PPC containing 40% pumice. As the pumice volume increased, the mortars' drying shrinkage and sulfate-induced expansion values decreased significantly. According to the sustainability analysis, the CO2 emissions of cement vary between 518 and 880 kg CO2/t. By using pumice instead of clinker, CO2 emissions of cement can be reduced. In SEM examinations, it was determined that pumice concentrated the microstructure. As a result, it has been determined that eco-friendly cement can be obtained by using 10% and 20% pumice in PPC production.
RDL Kalıcı Kaydıİncele - Review ArticleAçık Erişim2023The usability of the brick dust and blast furnace slag in zeolite-based lime mortars in different curing environments
Çavuş, Murat; Dayı, Mustafa; Dağcı, Yunus; Ulusu, Hayati
In this study, air lime was substituted by three different pozzolanic materials, namely BFS and brick powder and zeolite in different proportions as individual or double. The produced pozzolanic lime mortars were cured in air and high relative humidity environments. Special attention was given to the mechanical and physical properties of mortars under different curing conditions. In addition to the curing effect, the effect of using different pozzolans was also investigated. As a result, it has been observed that high relative humidity cure improves the mechanical properties of pozzolan mortars but is not effective on their physical properties. It shows that there are significant differences in the mechanical properties of mortars with pozzolan, which are exposed to different curing conditions, especially at an early age. It shows that the mechanical properties of mortars with pozzolan, which are exposed to different curing conditions, especially at an early age, increase twice on average. The high relative humidity cure shows that the non-pozzolan air-lime mortars slow down the performance properties. Overall, conditions of high relative humidity can more quickly improve the performance characteristics of puzolan mortars.
RDL Kalıcı Kaydıİncele - ArticleYalnız künye2016Investigation on characteristics of blended cements containing pumice
Ulusu, Hayati; Aruntas, Huseyin Yilmaz; Gencel, Osman
In this experimental study, the effects of 10, 20, 25, 30 and 40 wt.% pumice addition on properties of blended cement pastes and mortars were investigated. Pumice blended cements with a high fineness were produced by intergrinding Portland cement clinker, pumice and gypsum. Characteristics such as particle size distribution, soundness, setting times, chemical analysis, compressive and bending strengths, drying shrinkage, autoclave expansion and sulfate resistance were determined. In addition, the microstructures of some samples scanned by scanning electron microscopy were photographed. Compressive strengths of mortars produced with pumice blended cements were lower than that of Portland cement tested ages up to 360 days. Pumice blended cements increase durability, sulfate expansion, shrinkage and autoclave expansion.
RDL Kalıcı Kaydıİncele