Addition Of Waste Research Articles

FERMENTASI BIJI BUAH NANGKA (Artocarpus heterophyllus Lam.) MENGHASILKAN ETANOL OLEH Saccharomyces cerevisiae DENGAN ANALISA KROMATOGRAFI GAS (GC)

Research of bioethanol production from jackfruit seeds through fermentation using saccharomyces cerevisiae with the addition of tofu waste as nutrition source of microorganism. the aims of this research to determine the concentration of bioethanol that has been produced with the variation of concentration of tofu waste nutrients and variation of fermentation time. the hydrolysis process through enzymatic uses alfa-amylase on liquefaction process and glucoamylase on saccharification process. the fermentation process used Saccharomyces cerevisiae and tofu waste as a source of nutrition. variation of fermentation time 6, 8 and 10 days and variation of tofu waste nutrients concentration 0,75%; 1,5% and 2,25% (w/v). Ethanol content was obtained by gas chromatography analysis, the result showed the highest concentration of bioethanol obtained at the addition of tofu waste nutrients was 1,5% (w/v) and fermentation time for 10 days with bioethanol concentration obtained at 65,72%.

Waste for building material production as a method of reducing environmental load and energy recovery

Proper treatment and recycling of waste are crucial for the natural environment. Biowaste and ash might be used for ceramic building material production. Reduction in the amount of waste leads to the smaller burden on the environment, and it can also offer recovery of energy. This paper presents the results of an experimental study of the compressive strength of samples made from clay with waste additives: ash and sewage sludge. It was proven that the increasing amount of the waste materials decreases strength properties in all incineration temperatures. Scanning electron microscopy analysis was used to determine the internal structure of the samples. Tests of heavy metal leaching revealed that the concentration of copper, chromium, nickel, and zinc in leachate generally decreased with an increase in sintering temperature. Moreover, the level of chromium was observed to exceed the permissible level.

Influence of high-temperature exposure on the properties of gypsum-plastic waste composites: Thermophysical and microstructural analysis

Gypsum plasters are a versatile material with a wide range of applications due to their fireproof, thermal, hygroscopic, and acoustic properties. They are commonly used as a coating material to provide passive protection to structural components. Moreover, the construction sector recognizes the potential for gypsum material to address the issue of plastic waste by offering a recycling solution. However, it is crucial to consider the effect of polymeric waste aggregates on the behavior of the gypsum matrix against fire. To address this issue, this study aims to evaluate the impact of high temperature exposure on the microstructural and thermal properties of gypsum composites containing plastic waste. The study compares two different residues, crushed polypropylene (PP) sourced from disposable coffee capsules and nylon (PA6) fibres obtained from discarded fishing nets, with the reference material as partial replacements of the gypsum matrix. The samples are exposed to different high-temperature conditions, including service temperatures (23 ± 2 °C, 150 °C, and 300 °C) and fire temperatures (1000 °C). The physical, thermal, and chemical properties of the new composites are analyzed based on TGA and XRD analysis, and SEM and micro-CT methods to evaluate the effect of plastic residues on the microstructural properties of the gypsum matrix. Additionally, the cracking patterns induced by 1000 °C exposure are compared. The study finds that the nature of the gypsum matrix remains largely unchanged after plastic waste addition. However, the low cohesion degree of the interface transition zone (ITZ) between the products of different hydration is a critical feature that must be considered during the heating process. It could significantly affect the mechanical performance of the new composites. Furthermore, it is worth noting that the inclusion of PA6 fibres in the gypsum matrix improves the cracking performance after exposure to fire temperature. This is a result of better heat spread by microcracking generated after fibres melted. In conclusion, this study highlights the potential of using plastic waste as a partial replacement of gypsum matrix in construction applications. However, it is crucial to consider the impact of high temperature exposure on the mechanical performance of the new composites. Further research is needed to optimize the composition and processing parameters of the new composites to ensure their mechanical stability under fire conditions.

Effect of manganese-rich solid waste on soil phosphorus availability applied as monopotassium and rock phosphate in two contrasting soils

Manganese (Mn) mining produces a large amount of Mn-rich solid waste contributing to soil and groundwater pollution. Adding Mn-rich waste to soils could reduce mining pollution by allowing specialised plants to take up this mineral for growth, that is, phytoremediation. However, Mn interacts with other soil major and trace minerals. The interaction with phosphorus (P), a key element for plant nutrition and growth, has received less attention. In this study, we aimed to evaluate the effects of P sources (i.e. rock phosphate and monopotassium [KH2PO4]) and application rates on the P and Mn relationships in clay and sandy soils mixed with Mn-rich waste. Soils differing in texture were incubated for 60 days at room temperature (±20 °C), and changes in available P, Mn and soil pH were determined at 0, 30 and 60 days. The addition of Mn-rich solid waste significantly decreased available soil P in both soils with the greatest reduction of 62% and 52% from the sandy soil subjected to KH2PO4 and rock phosphate, respectively. In the clayey soil, the reduction was higher for the rock phosphate source implying more P was released from the rock phosphate in Mn-rich soils. This explanation was supported by the significant positive correlation between P and Mn for both soils when P is added in the form of rock phosphate. Our results suggest that Mn-rich waste is better in clay soils subjected to rock phosphate addition. Further research is needed to control Mn solid waste pollution levels in soils using specific crops with known phytoremediation properties. Significance: South African mining and smelting processes produce a lot of Mn-rich waste as a by-product that harms the environment if not appropriately managed. The efficient use of Mn-rich solid waste in agricultural soils is poorly studied; hence, this study focused on the role of soil type and Mn-rich waste addition on phosphorus release and availability.

Production of Biodegradable Polymeric Composites with the Addition of Waste.

Several solutions have been presented to minimize the environmental impact generated by polymers produced from petroleum resources. This work produced a biopolymer using glycerol, starch (<5) and macaúba epicarp fiber (10-15-20-25-30%) as reinforcement. The interaction of glycerol with starch was favored by the addition of acetic acid (CH3COOH). The pH was adjusted with sodium hydroxide (NaOH) at a concentration of 0.1 mol·L-1. The characterization was carried out through scanning electron microscopy (SEM), infrared reflectance-FTIR, water solubility, biodegradability and technological properties. Through the results obtained in this work, it is observed that the tensile strength and modulus of elasticity are influenced by the addition of the fiber concentration; the sample that received a 30% addition presented 19.17 MPa and 348.12 MPa, respectively. All samples showed low solubility in water and low density, in addition to a high rate of degradability in soil with mass loss corresponding to 59% over a period of three months. The results of this investigation are satisfactory for the production of materials that can be used in everyday life, replacing conventional plastic.

Experimental study of mixtures soil-industrial waste using simplex design for application in paving

The large amount of solid waste generated by industry is a concern for society. A possible solution is to incorporate these wastes into soils to improve their properties and contribute to sustainable development. The objective of this research was to conduct an experimental study on the chemical stabilization of two samples of tropical soils using two industrial wastes, electric arc furnace slag (EAFS) and fly ash (FA), using a design of experiments (DoE) of mixtures in a simplex centroid network. Seven mixtures were determined from the DoE for each soil sample. Using specimens of these mixes prepared at optimum moisture content, after a curing period of 7 days in a humid chamber, the properties were evaluated: unconfined compressive strength (UCS), California Bearing Ratio (CBR), and resilient modulus (RM). An improvement in the evaluated mechanical properties was observed with the addition of waste, especially with the addition of EAFS. The statistical software Minitab 18 allowed to obtain response surfaces for each mechanical property studied as a function of the pseudo-components of the mixtures. To determine the proportion of components that optimized the soil-waste mixtures, the desirability function was used, which resulted in the proportions of 80% soil, 20% EAFS, and 0% FA for both soil samples. Based on SEM and XRD tests, it was found that calcium silicate hydrate (C–S–H), calcium aluminate silicate hydrate (C-A-S-H), and calcium aluminate hydrate (C-A-H) were formed, which were responsible for improving the mechanical strength. The use of industrial waste to stabilize tropical soils with low bearing capacity proved to be a technically and environmentally viable alternative.

The compression characteristics and lateral earth pressure coefficient of sand–HDPE mixtures

In recent decades, considerable attempts through geotechnical study have been made to reduce plastic waste by recycling and reuse. The aim of this study was to reuse waste plastic mixed with sand for geotechnical application. To this end, large-scale oedometer experiments were carried out to examine the compressibility of Bandar-e Anzali sands stabilised with plastic-waste-originated high-density polyethylene (HDPE). Bandar-e Anzali is a populated coastal city in the vicinity of the Caspian Sea (northern Iran). Large-scale oedometer and direct shear tests were performed to study the applicability of HDPE chips mixed with sand at various HDPE contents (0, 2, 4, 6 and 8%). Based on the experimental tests, the addition of plastic waste to the soil improved the soil's strength, significantly raised its compressibility and decreased the undrained elasticity modulus. By adding 8% HDPE, the constrained compression modulus decreased to 50% at a pressure of 300 kPa due to the elastic deformability of HDPEs. However, at higher relative density, adding HDPE by more than 4% did not affect the coefficient of lateral earth pressure at rest.

Preparation of phosphogypsum-based cemented paste backfill and its environmental impact based on multi-source industrial solid waste

Cemented Paste Backfill (CPB) technology is considered as an effective method to solve the serious problems caused by the solid wastes’ accumulation, and to mitigate the risk of mined-out areas. However, the serious influence on the environment and higher pro-treating costs of solid wastes limits their application in CPB. Meanwhile, due to the high carbon emissions and high costs of Portland cement, its use as a binder in CPB is also limited. This paper used raw phosphogypsum (PG) as filler. Yellow phosphorus slag (YPS), fly ash (FA), steel slag (SS), and Portland cement were mixed to make a composite binder. Solid wastes addition was ranged from 80% to 98%. The feasibility of CPB co-preparation with a high percentage of multi-source industrial solid waste was verified by analyzing the performance and environmental impact of CPB produced with different percentages of solid wastes. The results showed that a higher PG addition was harmful to the property of CPB, leading to a lower fluidity, longer setting time, and weaken strength. However, the development and use of composite binder offset those negative aspects effectively. Composite binder is a CaO-rich binder that provides an alkaline environment for hydration reactions which enhanced CPB strength. Because its unconfined compressive strength reached to 3.1 MPa ∼ 19.5 MPa after 60 d’s curing. This will provide a highly strengthen support to the mine to be filled with CPB, thus hindering its re-collapse. The gradually increased hydration products observed from the microstructural characterization further corroborated the strength development path of the CPB. Moreover, the adsorption and precipitation process in the alkaline system contributed to the stabilization of the contaminants from those solid wastes. Therefore, the CPB technology based on the multi-source industrial solid waste is considered as a green, promising, and cost-saving choice on supporting safe mining and mitigating environmental pollution.

Recovery of Energy and Carbon Dioxide from Craft Brewery Wastes for Onsite Use

Interest in craft beers is increasing worldwide due to their flavor and variety. However, craft breweries have high water, energy, and carbon dioxide (CO2) demands and generate large quantities of high-strength waste and greenhouse gases. While many large breweries recover energy using anaerobic digestion (AD) and recapture CO2 from beer fermentation, little is known about the economic feasibility of applying these technologies at the scale of small craft breweries. In addition, compounds in hops (Humulus lupulus), which are commonly added to craft beer to provide a bitter or “hoppy” flavor, have been shown to adversely affect anaerobic microbes in ruminant studies. In this study, biochemical methane potential (BMP) assays and anaerobic sequencing batch reactor (ASBR) studies were used to investigate biomethane production from high-strength craft brewery waste, with and without hop addition. A spreadsheet tool was developed to evaluate the economic feasibility of bioenergy and CO2 recovery depending on the brewery’s location, production volume, waste management, CO2 requirement, energy costs, and hop waste addition. The results showed that co-digestion of yeast waste with 20% hops (based on chemical oxygen demand (COD)) resulted in slightly lower methane yields compared with mono-digestion of yeast; however, it did not significantly impact the economic feasibility of AD in craft breweries. The use of AD and CO2 recovery was found to be economically feasible if the brewery’s annual beer production is &gt;50,000 barrels/year.

Pemanfaatan Limbah Tulang Sapi dan Kaca Sebagai Substitusi Parsial Semen terhadap Bata Beton Pejal

Cement is a non-renewable natural resource, this natural resource will run out over time. In this research, waste cow bone and glass were used as a partial substitute for cement for solid concrete bricks. This study used a quantitative method in the form of an experimental method referring to the General Requirements for Building Materials in Indonesia (PUBI – 1982) and the Indonesian National Standard (SNI) 03-0349-1989, with a total of 24 test objects measuring 15 x 15 x 15 cm consisting of 4 variations of composition which were tested at the age of 7 days. The content of calcium oxide (CaO) in beef bones and silica (SiO2) contained in glass can be used to increase the hardening of concrete. Based on the test results, it was found that a mixture of solid concrete bricks with 4.5% beef bone powder and 3% glass powder (BSK I), produced an optimum average compressive strength of 290.56 Kg/cm² with a water absorption value of 2.445%, declared to be entering quality I solid concrete brick. This proves that the innovation of solid concrete bricks with the addition of bovine bone and glass waste can be stated to be better than conventional solid concrete bricks, resulting in solid concrete bricks that have high compressive strength, economical price and are environmentally friendly.Keywords : solid concrete brick, glass waste, cow bone waste

Pemanfaatan Limbah Tulang Sapi dan Kaca Sebagai Substitusi Parsial Semen terhadap Bata Beton Pejal

Cement is a non-renewable natural resource, this natural resource will run out over time. In this research, waste cow bone and glass were used as a partial substitute for cement for solid concrete bricks. This study used a quantitative method in the form of an experimental method referring to the General Requirements for Building Materials in Indonesia (PUBI – 1982) and the Indonesian National Standard (SNI) 03-0349-1989, with a total of 24 test objects measuring 15 x 15 x 15 cm consisting of 4 variations of composition which were tested at the age of 7 days. The content of calcium oxide (CaO) in beef bones and silica (SiO2) contained in glass can be used to increase the hardening of concrete. Based on the test results, it was found that a mixture of solid concrete bricks with 4.5% beef bone powder and 3% glass powder (BSK I), produced an optimum average compressive strength of 290.56 Kg/cm² with a water absorption value of 2.445%, declared to be entering quality I solid concrete brick. This proves that the innovation of solid concrete bricks with the addition of bovine bone and glass waste can be stated to be better than conventional solid concrete bricks, resulting in solid concrete bricks that have high compressive strength, economical price and are environmentally friendly.Keywords : solid concrete brick, glass waste, cow bone waste

Experiences in the Production of Wall Ceramics with the Addition of Carbonate-containing Wastes

The use of mining and metallurgical industry wastes containing calcium, magnesium, and strontium carbonates is described. The initial compositions and transformations occurring during the firing are considered. The best composition was chosen according to the results of laboratory studies, and based on that, ceramic brick was studied in real production conditions. The possibility of using mining and metallurgical industry wastes (dolomite and cake) as coloring pigments in the production of ceramic bricks has been theoretically substantiated and experimentally proven. Magnesium and strontium carbonates, along with calcium carbonates, participate in the formation of multicomponent systems, on the basis of which it is possible to obtain wall ceramics that meet modern requirements.

Life cycle assessment of soil stabilization using cement and waste additives

Environmental measures show that the effect of global temperature rise goes beyond the natural cycle of the Earth’s environmental system, which affects the social, economical, and health conditions of humanity. In this respect, initially, the UN’s sustainable development goals were adopted where, more recently, a UN net-zero coalition was formed to cut greenhouse gas emissions to as close to zero as possible by 2050 to resist foreseen catastrophic outcomes. As a result of these overwhelming goals and regulations, many nations are setting policies to achieve those targets. Nevertheless, such targets, to the best of our knowledge, have not penetrated well into construction applications. In this study, in addition to the mechanical responses of three different waste additives (bottom ash, marble dust and tire rubber powder to replace cement to stabilize problematic soils, a life-cycle assessment was performed to evaluate environmental impacts. Furthermore, a novel impact-performance approach has been introduced to satisfy safety, performance, and sustainability criteria. In this respect, unconfined compressive strength (UCS), initial stiffness (G0), accumulated loss of mass (ALM) due to wet-dry cycles, and life-cycle analysis (LCA) were performed on artificially cemented (7%, 10%, and 13%) clay specimens, compacted at 1600 and 1800 kg/m3 and cured for 28 days. Further, bottom ash (BA) (10% and 20%), marble dust (MD) (20% and 40%), and tire rubber powder (TRP) (2.5%, 5%, 10%, and 20%) were used to replace the cement, which is known for its great environmental impact. It is reported in this study that 2.5% TRP replacement of cement at low density seems to be the optimum dosage and additive, among others, to provide the best performance (UCS, G0, and ALM). Furthermore, the increase in cement content and density results in a positive contribution to performance indicators and a negative contribution to environmental impact. However, when impact-performance is considered, the opposite was observed, i.e., the rise in cement content, additive content, and density results in favourable contributions.

EFFECTS OF MIXING ADDITION OF THE GREENERY WASTES ON THEIR REMEDIATING EFFECTS ON PETROLEUM POLLUTED SOIL

In this study, greenery wastes of Platycladus orientalis (Po) and the other 5 species which are commonly used in urban landscaping were collected. Monospecific greenery wastes and their 1:1 mixtures containing Po waste were used to treat contaminated soil with a petroleum content of 15.00 g/kg, to conduct a 150-day laboratory remediating experiment at 20-25℃, under a soil moisture of 50% of the saturated water holding capacity. The effects of mixed addition of greenery wastes on their re-mediating effects on contaminated soil were detected, to provide scientific basis for the reasonable utilization of greenery waste in contaminated soil remediation. The results indicated that: (1) Mixed addition of Po waste with Picea asperata (Pa), Acer truncatum (At), Ginkgo biloba (Gb) or Juniperus formosana (Jf) waste significantly enhanced their effect of removing petroleum contaminants, espe-cially for removing aromatic and non-hydrocarbon substances; while the mixed addition of Po waste with Pinus tabuliformis (Pt) waste significantly weakened their remediating effects. The mixed addition of Po waste with Gb or Jf waste significantly enhanced their effects of replenishing soil available N and P; the mixed addition of it with Pa, Pt, Gb or Jf waste tended to enhance their effects of stimulating the activities of soil invertase, urease, phosphatase and dehydrogenase, while the mixed of it with At waste tended to weaken their simulating effects. (2) Mixed litters with high contents of C, N, terpenoids and amino acids, and chemical dispersion facilitated the degradation of petroleum contaminants, while those with high contents of soluble saccharides and total organic acids/terpenoids led to contrast effects; mixed litters with high N content facilitated the increment of soil enzymatic activities, while those with high contents of total organic acids and terpenoids led to contrast effects. In conclusion, mixed addition of Po and Jf, Po and Gb, and Po and Pa wastes might enhance their overall remediating effects on petroleum contaminated soil, while mixed addition of Po and Pt wastes might weaken their ability of removing the contaminants, and this mixing form of greenery wastes should be avoided.

THE UTILIZING OF RECYCLED PLASTIC WASTE AS AN ALTERNATIVE FOR ZERO CEMENT PAVING BLOCKS

The problem of plastic waste that needs to be handled and managed optimally can cause environmental damage. This study aims to test the compressive strength and water absorption value of paving blocks made of plastic which are designed using a mixed variation of V50-50 (50% sand, 50% plastic), V25-75 (25% sand, 75% plastic) and V0-100 (0% sand, 100% plastic) of the total proportion of the paving blocks mix. The method is carried out by melting PP (Polypropylene) mineral glass plastic, mixing with sand based on variations, printing according to the size of the paving block, and using as a test sample in the form of a dice. The average compressive strength test results show that the model with code V25-75 has a relatively higher compressive strength value than V50-50 and V0-100. The average compressive strength value of the sample with code V25-75 is 11.53 MPa, followed by code V50-50 of 9.63 MPa, and the lowest is coded V0-100 of 3.70 MPa. The compressive strength value is influenced by the optimal percentage between sand and plastic; plastic serves as a binder for sand in a mixture of paving blocks. The rate of water absorption value will continue to decrease along with the addition of plastic waste in the paving block mixture; V50-50 is 1.44, V25-75 is 0.88, and V0-100 is 0.16. This research is expected to be applied by the community to make paving block products to reduce the amount of plastic waste globally.

Thermal and acoustic properties of new plasterboard composites with additions of cigarette butt waste

A set of gypsum composites with four different types of cigarette butt morphologies were developed to evaluate thermal and acoustic properties. In addition, for the acoustic samples, another set of four different types of surface finishes were developed to assess the acoustic absorption coefficient. The thermal results showed that the recycled material could work as thermal insulator in all morphologies. But for acoustic, the residue must be placed vertically on the surface to achieves similar values to materials considered acoustic absorbers. Then, it is possible to manufacture a plasterboard with this composite that improves the properties of regular ones.

Utilization of spent substrates and waste products of mushroom cultivation to produce new crops of Pleurotus ostreatus, Pleurotus eryngii and Agaricus bisporus

Five agro-industrial residues, their corresponding spent mushroom substrates (SMS), commercial fresh and spent mushroom compost of Agaricus (SMC) and Pleurotus ostreatus (SMS GZ) cultivation, Pleurotus and Agaricus waste (stipes/mishappen mushrooms) were combined and re-utilized as novel substrates for the cultivation of P. ostreatus, P. eryngii and A. bisporus mushrooms. SMSs/ SMC were used up to 40% (treatment 1 and 2), while 20% of mushroom waste were added in fresh and spent substrates (treatment 3 and 4). The impact of different substrates on mycelial growth rate and biomass production was examined. Then, Pleurotus spp. were cultivated on the most promising substrates and essential cultivation aspects (earliness, total mushroom yield, biological efficiency-BE) and carposomes’ quality parameters (weight, morphological characteristics) were evaluated. Laccase and endoglucanase production by Pleurotus species were also determined at 50 and 100% of colonization stages. All species showed their fastest mycelial growth rate (up to 5 mm/day) on substrates consisted of SMC, whereas many combinations of species/substrate enhanced biomass production. The SMS GZ supplementation positively affected laccase activity; in the cultures of P. ostreatus and P. eryngii the highest values were 62,539 and 17,584 U/g d.w., respectively. On the contrary, small amounts of endoglucanase were produced (0.007 to 0.322 U/g d.w.); the greatest production was recorded for P. ostreatus at full colonization. Regarding fermentation in bags, significant amount of total mushroom yield was produced in all substrates and those with SMS GZ supported the fastest earliness period and the highest BE for both Pleurotus species. BE values ranged from 54 to 133% for P. ostreatus and from 53 to 121% for P. eryngii. Concerning morphological characteristics, mushroom waste addition seemed to affect them positively. The data included in this paper support the effective re-utilization of different types of SMS and mushroom waste for fungal mass and enzymes’ production and for new high quality Pleurotus spp. carposomes.

The Utilization of Jackfruit (Artocarpus heterophyllus L.) Waste towards Sustainable Energy and Biochemicals: The Attainment of Zero-Waste Technologies

The valorisation of food and fruit wastes has the potential for the production of sustainable energy and biochemicals. Approximately 70% of the weight of the original jackfruit (Artocarpus heterophyllus L.) fruit is lost during its processing as waste in the form of peeled skin and core, both of which have not been utilized and, thus these contribute to disposal as well as pollution issues. The major components such as cellulose and hemicellulose can be easily biologically transformed into bioenergy sources such as ethanol, methanol, and butanol; valuable phenolics and biotechnological products such as pectin, citric acid, bromelain, ferulic acid, and vanillin; and many other products. These residues can also be utilized as essential sources for the biological transformation process, leading to the production of numerous products with added value, such as phenolic antioxidants, phenolic flavour compounds, and organic acids. Thus, the value addition of jackfruit waste can support sustainable solutions towards food and nutritional security. In this way, zero waste can be achieved through novel biorefineries, which are critically highlighted in this paper. Furthermore, novel technologies for the conversion of jackfruit waste are summarized with recent findings.

Response of Cucumber Pants to the Addition of Animal Waste and Dry Yeast Suspension

A factorial experiment was carried out during the year 2021 in one of the villages in the Abu Ghraib district – Baghdad, to evaluate the effect of adding animal waste and dry bread yeast suspension on some vegetative growth characteristics of cucumber plants (Hadeel hybrid) grown under a protected environment. Three types of animal wastes (cattle, sheep and poultry) and dry bread yeast suspension were selected and the control treatment without adding any organic waste. The results indicated that poultry manure showed the best effects in the studied traits, which included leaf area ) of 31.69 cm2 (, dry weight of shoot )40.0 g(, number of leaves )32.73 leaf plant-1 ), stem diameter (11.48 mm), plant length (224.3 cm) and number of nodes 33.73 node plant-1 ).On the other hand, adding dry yeast suspension to plants improved in all studies of vegetative growth characteristics compared to the control treatment. Keywords: Cucumber, fertilize, organic manure, biofertilizer, vegetative growth.

Mechanical properties, high temperature resistance and microstructure of eco-friendly ultra-high performance geopolymer concrete: Role of ceramic waste addition

This study aims to develop ultra-high performance geopolymer concrete (UHPGC) using fine ceramic waste (FCW) as a partial fine aggregate. In this research, 12 mixes were designed, prepared, and tested to evaluate the influence of ceramic waste as a partial replacement of fine aggregate up to 22.5% on the performance of UHPGC. The fresh properties, mechanical properties, durability, and high temperature resistance of the developed material were investigated. The ecological assessment of UHPGC incorporating FCW has also been analyzed via life cycle assessment. The experimental results showed that the incorporation of FCW accelerates the setting time and reduces the slump of the fresh concrete. For hardened concrete, it has a relatively negative effect on mechanical properties to a certain extent. The compressive strength decreased to 123 MPa with the incorporation of 22.5% FCW. However, with smaller replacement percentages, 7.5 and 15%, the concrete exhibited better strength than 22.5%. This reduction may be attributable to the lower bond between the geopolymer gel and the ceramic particles. It was additionally found that the UHPGC's sorptivity increased simultaneously with increasing FCW content. For, high temperature resistance, inclusion of fine ceramic waste showed enhancement of residual strength as compared to the control mix after 700 °C exposures. A microscopic investigation showed that samples utilizing ceramic aggregate had fewer micropores and cracks after being subjected to high temperatures. Besides, TGA analysis revealed that mixtures using FCW were more stable up to 650 °C. Finally, using FCW can reduce carbon emissions and energy consumption to acceptable levels of 267 kg CO2eq/t and 571 MJ/m3, respectively, with low economic targets. Based on the obtained results, ceramic waste can be optimized and exploited as potential sources for manufacturing eco-friendly UHPGC with improved resistance to high temperatures and minimum harmful effects on mechanical properties and durability.