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Conobea scoparioides (Plantaginaceae) is an herbaceous plant known as “pataqueira” that grows wild in seasonally wet areas of the Amazon region. It is used for aromatic baths and anti-protozoan remedies by the Brazilian Amazon native people. The main volatile compounds identified in the essential oil of “Pataqueira” were the phenolic monoterpenes thymol and thymol methyl ether and their precursors, the monoterpene hydrocarbons α-phellandrene and p-cymene. A hydrotalcite synthesized from blast-furnace slag exhibited a 3:2 (Mg/Al) molar ratio, and this layered double hydroxide (LDH) was evaluated as a catalyst in converting the main monoterpenes of the “Pataqueira” oil. This action significantly increased the thymol content, from 41% to 95%, associated with the percentual reduction in other main components, such as thymol methyl ether, α-phellandrene, and p-cymene. The LDH reaction showed a strong tendency towards producing hydroxylated derivatives, and its behavior was similar to the hypothetical plant biosynthetic pathway, which leads to the production of the monoterpenes of “Pataqueira” oil. Thymol and its derivatives are potent antiseptics applied in pharmaceutical and hygienic products as antibacterial, antifungal, and antioxidant properties, among others. The present work reports a natural source with a high thymol content in aromatic plants from the Amazon, with evident economic value.

In order to realize the synergistic utilization of calcium silicon slag, fly ash and blast-furnace slag, this paper researched on hydration mechanism of calcium silicon slag composite geopolymer through preparation experiments of the calcium silicon slag composite geopolymer under different ratio of fly ash / blast-furnace slag.The results show that the calcium silicate slag base geopolymer is a binary composite cementitious material mainly composed of C—S—H and C(N)—A—S—H, which is formed by the hydration of β-calcium silicate itself and alkali-activated hydration.Compared with crystalline minerals, glass minerals are more prone to reaction with Ca(OH)2 and sodium silicate, resulting in a large amount of unreacted mullite remaining in the hydrates of 7 d when the fly ash / blast-furnace slag ratio is more than 0.5, but the mullite will continue to hydrate with the extension of curing time, and worm-like tetranatrolite and strip-like beidellite will be formed at 28 d.At the same time, when fly ash / blast-furnace slag ratio is 1.0, micromorphology of calcium silicate slag composite geopolymer is the most evenly distributed and dense, and its 28 d compressive strength reaches maximum 37.9 MPa.So, it indicates that the best synergistic effect among calcium silicon slag, fly ash and blast-furnace slag can be released under this condition.

The article proposes a technological line for recycling the blast-furnace slag. This line makes it possible to obtain the crushed stone for road building, which has high water and frost resistance. The design of replaceable working equipment of a single-bucket excavator, with replaceable working tools for loosening frozen slag in dumps and preparing it for use in road building, is proposed. The results of testing the manufactured replacement working equipment are presented. The results of mathematical processing of experimental data using the approximation method are presented, as well.

Concrete structures exposed to high levels of chemical attacks are assigned to exposure class XA3, which recommends separate concrete protection or a special expert solution to ensure durability. Due to the partial substitution of Portland cement by blast-furnace slag, an increased resistance to acid attacks could be achieved within the framework of a research project. The technical and ecological advantages of cements containing granulated blast-furnace slag were exploited through chemical, granulometric and concrete technological optimizations. Despite extensive parameters, a statistical test design (DoE) was able to limit the experimental effort, thus defining principles for the conception of binder systems with increased chemical resistance.Mortar prisms indicated that the use of (ultrafine) blast-furnace slags (up to 13,000 cm2/g according to Blaine) with a broad particle size distribution can have a positive effect both on the capillary/gel pore ratio and on the calcium hydroxide content in the cement stone. Furthermore, the chemical composition of the blast-furnace slag as well as the water-binder ratio are decisive influencing factors for the acid-resistance, which was confirmed in accelerated acid resistance tests on concretes (pH-stat method). After 13 weeks of storing concrete specimens in sulfuric acid (H2SO4, pH 3.5), reduced damage depths and lower weight losses were observed compared to conventional binder compositions. The results serve as a basis for the development of highly acid-resistant concretes using blast-furnace slag-containing binder systems. Currently, the acid resistance of those concretes is being investigated in a long-term study by outsourcing representative test specimens into the Emscher sewer.

Foam concrete is lightweight concrete. It has been proven to be more environmentally beneficial than conventional concrete because it uses less natural resources. Besides, saving natural resources and making effective use of industrial waste as aggregate in concrete is a pressing issue. Currently, the effective use of industrial waste is of interest to many researchers. As a result, the current study seeks to investigate alternative fines sources by examining the impact of granular blast furnace slag as a substitute for sand aggregate on the properties of foam concrete. This paper builds on the author’s earlier research into the impact of blast furnace slag on the properties of foam concrete. In total, four foam concrete mixtures with densities of 1700 kg/m3 and 900 kg/m3 and sand replacement amounts of 100% blast furnace slag were created. GOST has been used to measure the compressive strength, elastic modulus, and porosity of foam concrete. According to the findings, using blast furnace slag instead of sand makes foam concrete thicker and less porous. These findings result in higher foam concrete compressive strength and elastic modulus. Furthermore, the author used Hoff’s equation and Zheng’s equation to calculate theoretical porosity and compare it to observed porosity. The measured results indicate that the theoretical and measured porosity have a reasonably close relationship.

Abrasion resistance is one of the most important durability properties of concrete. Especially, highway, airport and industrial floor pavements should be resistant to abrasion. Recently, many research studies have been carried out on the utilization of industrial by-products in concrete. Granulated blast-furnace slag (GBFS) and bottom ash (BA) are two of these by-products. BA is not generally utilized in concrete and has a limited usage. It is mostly dumped, leading to additional costs and environmental problems. On the other hand, both GBFS and BA have potential for concrete production to provide sustainability. They can substitute fine aggregate thanks to their positive effects on concrete durability. Therefore, the aim of this study was to investigate the abrasion resistance of concretes produced with GBFS and BA substituting fine aggregate. Three different concrete series were produced by replacing fine aggregate with GBFS, BA and both of them by mixing them at equal ratios. The replacement ratios of by-products were 10%, 20%, 30%, 40% and 50% by volume. Compressive strength and Bohme abrasion tests were conducted on series. Results were compared to each other. It can be said that abrasion resistance can be improved by these by-products.

A Ca-K geopolymer matrix based on clay material and blast-furnace slag was filled with aggregates, ash pellets made from fluid fly ash, and the interlayer formed between the two components was studied. The scanning electron-microscopy investigation of the inseparable interlayer demonstrated that the pellets were not only enveloped in a geopolymer matrix but also incorporated through a thin, yet identifiable, surface pellet layer. The migration of calcium and potassium ions was detected and that changes in the quantity of these ions arise from their mobility. The interlayer on the edges of ash pellets was also studied by infrared analysis, which in this layer proved bands belonging to both participants, the matrix and the pellets. Based on the results, two different materials prepared from wastes could be used for the preparation of a new composite material and thus facilitate waste-material disposal.

Climate change is one of the most important issues affecting the future of the planet. Then, a lot of resources are being used to actively work on climate change issues and greenhouse gas reduction. Greenhouse gas (GHG) emissions are monitored by each country and reported yearly to the United Nations Framework Convention on Climate Change (UNFCCC). The Intergovernmental Panel on Climate Change (IPCC) published the document entitled “2006 IPCC Guidelines for National Greenhouse Gas Inventories” to provide the calculation rules and the way to inform the UNFCCC of the national GHG emissions. Currently, this document does not give a procedure to calculate the net carbon dioxide emissions to the atmosphere due to the Portland cement clinker production. The purpose of this paper is to get reliable relationships to better calculate the CO2 uptake by ground granulated blast-furnace slag (GGBFS) mortars. The application of this material cured under controlled conditions could help minimize environmental impact. Carbonation coefficient versus 28-day compressive strength relationship of mortars elaborated with GGBFS and cured underwater for 0, 1, 3, 7, 14, or 28 days were obtained. The main finding is the extreme sensitivity of the GGBFS mortars to the curing intensity and, therefore, they can be used cured under controlled conditions to minimize carbon footprints.

The paper shows the results of an experimental tests campaign carried out on concretes with recycled aggregates added in substitution of sand. Sand, in fact, has been totally replaced once by blast-furnace slag and fly ashes, once by blast-furnace slag and microsilica. The aim is both to utilize industrial by-products and to reduce the use of artificial aggregates, which impose the opening of pits with high environmental damage. The results show that in the concretes so made the water absorption capacity has reduced and durability has improved. The test campaign and the results described in the present article are certainly useful and can be especially utilized for research on a larger scale in this field.

The article presents the current possibilities for the utilization of blast-furnace and steelmaking slag in the realities of the Polish economy. Particular consideration is given to the legislation applicable to this area and to the physical and chemical requirements imposed on this material. Some aspects of environmental protection are described, and selected indicators are given, which must be met by this material to be used in various fields, such as road construction or cement production. Economical factors that are crucial to perceiving the slag as a standard valuable metallurgical product is also taken into consideration in the analysis.