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This research presented, for the first time, the results of the successful application of the waste press sludges, WSLP (plant for lacquer and paint) and WSEP (powdery enamel plant), from a wastewater treatment plant generated during heating device production in the construction industry. The results of WSEP characterization and its influence on cement paste, mortar, and concrete properties showed that this material could be used as a cement replacement (with a maximum replacement amount of 20%) in producing mortar and concrete. Although waste WSLP sludge does not possess pozzolanic properties and does not meet the criteria prescribed by the standards for application in mortar and concrete due to its chemical inertness and fineness, as well as its extended setting time, it can be used as a replacement for stone filler or other powdered mineral admixture in the production of self-compacting concrete (SCC) in amounts up to 100%, with a maximum quantity of up to 100 kg/m3. The obtained results indicate that with the appropriate conversion, waste sludges, despite representing hazardous waste, can be used as safe products in the construction industry; i.e., the waste material can become a useful and valuable raw material by applying (respecting) all of the principles of the green economy.

Waste vitreous enamels from the heating device production process were used for partial replacement of cement in the mortar and concrete production industry. This waste, due to the high content of heavy metals, is classified as hazardous waste. At the same time, waste vitreous enamels possess pozzolanic activity and belong to class 15 (WEP—generated during the production process of heating devices, premix technology), that is 5 (WETM—generated during the production process of heating devices, classic technology) of pozzolanic materials. The purpose of this research was to develop new composites from these wastes to reduce the deposition of the toxic compounds and reduce their environmental impact. The chemical and physical-chemical characterization and pozzolanic activity of the raw waste materials were studied by a mixture of complementary methods, as well as physical-mechanical characterization and a leaching test of mortar and concrete composites. The results indicate that the replacement of cement with WEP up to 30%, or with WETM up to 20% does not significantly affect the quality of concrete in comparison to the quality of the reference concrete prepared with 100% cement. The leaching test showed no significant release of toxic elements for both obtained composites.

This paper presents the results of testing the physical and mechanical properties and durability of geopolymer mixtures. Fly ash was used as the basic binder, while its replacement was performed with wood biomass ash.The initial and final setting time were tested on the geopolymer paste, while flow value and bulk density were tested on the fresh mortar. Compressive and flexural strength and sulfate and freeze-thaw resistance were tested on hardened geopolymer mortar. Based on the most optimal results of mortar testing, the composition of concrete was determined, and slump, bulk density, compressive and flexural strength, penetration of water under pressure and sulfate and freeze-thaw resistance were tested. According to the results of compressive strength tests of geopolymer materials and concrete exposed to sulfate solution attack, the mixtures prepared with the addition of 20% wood biomass ash showed better sulfate resistance than the mixtures prepared only with fly ash.

Solving problems with hazardous waste materials is of crucial importance today. In the presented study, the application of waste vitreous enamel as a cement replacement up to 30% in mortar and concrete production was investigated. The chemical and physical-chemical characterization of the starting material was performed, as well as a leaching test and physical-mechanical characterization of mortar and concrete mixes. Obtained results showed that, due to its chemical composition, the vitreous enamel used must be classified as hazardous waste. At the same time, it possesses pozzolanic properties and satisfies minimal criteria for use as a cement replacement. Testing mortars and concrete mixes indicate that waste vitreous enamel can be applied as a construction material for cement replacement in the maximal amount of 20%. The leaching test was performed in accordance with international standard EN 12457-2 on hardened mortar with a maximal cement replacement of 20%. The results showed that there was no significant release of toxic elements, i.e., that the practical application of hazardous waste vitreous enamel in the construction industry may be fully in line with environmental standards.

Solving problems with hazardous waste materials is of crucial importance today. In the presented study, the application of waste vitreous enamel as a cement replacement up to 30% in mortar and concrete production was investigated. The chemical and physical-chemical characterization of the starting material was performed, as well as a leaching test and physical-mechanical characterization of mortar and concrete mixes. Obtained results showed that, due to its chemical composition, the vitreous enamel used must be classified as hazardous waste. At the same time, it possesses pozzolanic properties and satisfies minimal criteria for use as a cement replacement. Testing mortars and concrete mixes indicate that waste vitreous enamel can be applied as a construction material for cement replacement in the maximal amount of 20%. The leaching test was performed in accordance with international standard EN 12457-2 on hardened mortar with a maximal cement replacement of 20%. The results showed that there was no significant release of toxic elements, i.e., that the practical application of hazardous waste vitreous enamel in the construction industry may be fully in line with environmental standards.

The demand of the contemporary society for renewable energy sources lead to the increase of the bio-power plants. Accordingly, the amount of ash generated by burning the biomass is increased, and its disposal becomes a large environmental problem. The paper presents the research of potential use of biomass wood ash as a partial replacement for coal fly ash (10%, 20%, 30% and 40% of mass) in production of self-compacting concrete (SCC). The effects of biomass wood ash on the properties of SCC in fresh and hardened states have been examined, as well as on the properties of durability. Test results indicated that the biomass wood ash slightly reduces the flowability and passing ability of SCC, while its addition enhances the viscosity of SCC and significantly prevents segregation and bleeding. SCCs with the contents of biomass wood ash up to 20% have approximately same mechanical strength as the reference mixture. Biomass wood ash has no negative effect on the resistance of concrete to the action of water under pressure, but a decrease of freeze/thaw resistance with de-icing salt is detected as its contents increases. The addition of biomass wood ash into SCC increases the drying shrinkage in the initial period of drying (up to 14 days), and it is decreased in a later phase. © 2021, Strojarski Facultet. All rights reserved.

The presented study is a continuation of the research with the aim of finding a useful value of hazardous waste slag generated by the combustion of lignite in heating plants and its application in the construction industry. The different amounts of cement (10%, 15%, 20% and 25%) were replaced with waste slag and silica fumes in mortars and concrete production. Detailed physical–mechanical characterization was performed on the mortar and concrete samples according to standard procedures. Test results indicated that the replacement of cement with slag and silica fumes reduces the physical and mechanical properties of mortar and concrete, but cement composites retained the required structural properties. If 15–20% is considered an acceptable level of compressive strength decrease, then it can be concluded that waste slag can be implemented in practice and be used as a construction material, with cement replacement in the maximal amount of 20% (17.8% of slag and 2.2% of silica fumes). On hardened mortar samples with maximal possible cement replacement (20%), physical–chemical characterizations were performed and included X-ray and infrared spectrophotometry, scanning electron microscopy, and thermal analysis. Results showed the absence of new phases and the presence of only those which were characteristic for starting samples, predominantly portlandite, quartz, calcite and calcium silicate-oxide

The presented study is a continuation of the research with the aim of finding a useful value of hazardous waste slag generated by the combustion of lignite in heating plants and its application in the construction industry. The different amounts of cement (10%, 15%, 20% and 25%) were replaced with waste slag and silica fumes in mortars and concrete production. Detailed physical–mechanical characterization was performed on the mortar and concrete samples according to standard procedures. Test results indicated that the replacement of cement with slag and silica fumes reduces the physical and mechanical properties of mortar and concrete, but cement composites retained the required structural properties. If 15–20% is considered an acceptable level of compressive strength decrease, then it can be concluded that waste slag can be implemented in practice and be used as a construction material, with cement replacement in the maximal amount of 20% (17.8% of slag and 2.2% of silica fumes). On hardened mortar samples with maximal possible cement replacement (20%), physical–chemical characterizations were performed and included X-ray and infrared spectrophotometry, scanning electron microscopy, and thermal analysis. Results showed the absence of new phases and the presence of only those which were characteristic for starting samples, predominantly portlandite, quartz, calcite and calcium silicate-oxide

The connection between eco and building materials can be successfully accomplished by using geopolymers. Geopolymers are composite materials made of long chain molecules incurred by polymerization of geopolymer binders. Usually, geopolymers are defined as a solid and stabile aluminosilicate materials, made of industrial byproducts and liquid solutions such as NaOH and Na2SiO2. …The experimental part of the dissertation, contains the results of physical-mechanical, microscopic and durability properties of geopolymer mortars and concrete based on fly ash. For the purpose of determining the effect of different byproducts on characteristics of geopolymer mixtures, 24 batches of mortar and 8 batches of concrete were made and tested. Mass percentages of ladle slag, wood ash, red mud and waste glass in respect to the total mass of the binder was 0 to 20%, varied in 5 % steps of replacement. Mass percentage of ground granulated blast furnace slag in respect to the total mass of the binder was 0 to 100%, varied in steps of 20 % steps of replacement. All batches were made by using binder with the particle size smaller than 0,09 mm. The samples of geopolymer mortar and concrete were cured at an ambient temperature. …According to the test results some recommendations for the possible application of fly ash and other industrial byproducts for making geopolymer mortars and concretes are made. It has been proved that geopolymer mortars and concretes might be used as a construction building materials. Furthermore, because of their physical-mechanical characteristics and durability properties, they can be alternative solution for the traditional mortar and concrete mixtures.

Numerous factors influence the complexity of environmental and waste management problems, and the most significant goal is the reuse of materials that have completed their “life cycle” and the reduction in the use of new resources. In order to reduce impact of waste slag on the environment, in the present study, waste slag, generated in heating plants after lignite combustion, was characterized in detail and tested for application as a replacement for cement in mortar or concrete production. For physical–chemical characterization of slag, different experimental and instrumental techniques were used such as chemical composition and determination of the content of heavy metals, investigation of morphological and textural properties, thermal analysis, X-ray, and infrared spectroscopy. Physical–mechanical characterization of slag was also performed and included determination of activity index, water requirement, setting time and soundness. A leaching test was also performed. Presented results show that waste slag may be used in mortar and concrete production as a partial cement replacement, but after additional combustion at 650 °C and partial replacement of slag with silica fume in the minimal amount of 12%. The maximal obtained cement replacement was 20% (17.8% slag and 2.2% of silica fume).

The Bayer process is the main industrial process covering 90 % of global production of alumina. The sintering process deals with the medium and low grades of bauxite resource. During the alumina production process, red mud is generated as a waste rock which consists of: hematite, Goethite, quartz, boehmite, calcite, tricalcium aluminate, zinc and magnesium oxides, sodium hydroxide etc. Due to high viscosity of the mud, prior to transport to the waste industrial water is added in the share of 10–15 % prior to transport to the waste disposal dump so that the pipeline transport would be facilitated. What makes red mud a hazardous pollutant is the alkaline liquid phase (Zlatičanin et al. in Prot Mater 53:292–298, 2012, Paramguru et al. Extr Metall Rev 26:1–29, 2005) [1, 2]. From the aspect of stored quantities, red mud represents a significant environmental problem (Zlatičanin et al. in Prot Mater 53:292–298, 2012) [1]. A large number of methods for sustainable disposal of red mud was developed, however, it a tendency to use the red mud in other production process, up to 20 % of it until 2025. The potential for utilization of red mud is seen making masonry products, ceramic tiles, in replacement of a part of cement or aggregate, as a component in self-compacting concretes, geopolymers. The paper provides a review of the developed methods for storage of red mud, with a goal of sustainability and cost-effectiveness. Simultaneously, the paper provides the review of potential application of red mud as a component of building materials. In the experimental part was considered the usage of red mud as a mineral admixture for making self-compacting concrete.