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Demand for green environments has stimulated research on the migration from conventional to renewable energy sources. In the case of combustible energy for domestic applications, briquettes produced from biomass have proven to be a good replacement for wood fuel. In this study, investigation on the performance analysis and optimization of mix ratio of briquettes produced from sugarcane bagasse using composite binders (waste paper and clay) was carried out. Box-Behnken Design feature of the Design Expert software was employed for the optimization of the briquettes mix ratio. Briquettes were produced from sugarcane bagasse based on the optimum conditions of 9.12% clay, 12.57% waste paper, 78.31% proportion of sugarcane bagasse and 5 KN compaction pressure. The produced briquette was found to have a compressive strength of 6.4715 MPa and 0.857 g/min burning rate. The results of the study shows that the experimental values were close to the predicted values with a percentage error of 3.11% for compressive strength and1.79% for burning rate which confirms the validity and adequacy of the predicted models.

Currently, most of the collected waste medium-density fiberboards (MDF) is incinerated or landfilled, as economically viable recycling methods are yet to be developed. By steam refining waste medium-density fiberboards (MDF), it is possible to hydrolyze the incorporated resins and isolate a high yield fiber fraction. Further refining of the steam treated fibers might enable the fibers to be utilized in applications such as paper packaging, facilitating a cascading use of the waste material stream. To this end, intimate knowledge of the material is needed. In this study, the steam refined fibers of two waste MDF samples containing differing amounts of softwood and hardwood underwent refining and beating. The resulting fibers were characterized regarding their morphology and paper test sheets were produced to evaluate their strength (compression-, tensile- and tear-strength). Distinct differences in response to refining between the MDF samples were apparent. For the sample with the higher hardwood share an increase in strength properties with increasing steam treatment severities could be observed and it was possible to produce test sheets with comparable compression strength to recycled pulp for industrial corrugated paperboard. For the sample with a higher share of softwood, the steam treatment severity did not show any influence on fiber morphology or paper properties, and the resulting paper strength was low in comparison to the other steam refined waste MDF sample. Graphic Abstract

Objectives: The objective of the study was to study the compressive strength of the partially replaced paper mill waste in cement. Methods/ Statistical analysis: The concrete cube specimen were prepared for compressive strength test. In this study, the cement has been replaced with 20%, 30%, 40% and 50% of hypo sludge. The specimens were cured for two different ages (7 days and 28 days) and tested for compressive strength. The quadratic polynomial prediction equation was proposed using Response Surface Methodology (RSM). The prediction model was developed using the experimental output results. Thus, the prediction model facilitates the further research work to be conducted by researchers on paper mill waste replacement. The rate analysis was also further carried out to show the cost effectiveness of using the waste replacement in cement. Findings: The test was conducted on the compressive strength (7 days and 28 days) of control specimen (0%) and partial replacement of 20%, 30%, 40% and 50% of cement using the hypo sludge. Thus, 20% replacement of cement using hypo sludge has shown good compressive strength than the control specimen. The cost of 20% paper mill waste was less when compared to the cost of control specimen. Novelty/ Applications: The compressive strength of 20% partial replacement of paper mill waste in cement can be used in further construction. The prediction model can be used to predict the future compressive strength of partially replaced paper mill waste concrete. Keywords: Ordinary Portland cement; Paper mill waste; Hypo sludge; Partial replacement; RSM

Research is devoted to the problem of recycling waste of the Baikal Pulp and Paper Mill, whose activity has caused serious damage to the ecological environment of Lake Baikal and its environs. Grouting waste production is currently the most effective possible decision to the problem of pollutants, such as sludge-lignin and ash, in water objects and groundwater. The results on the grouting of liquid and solid waste from the Baikal Pulp and Paper Mill, represented by sludge lignin and ash, are presented. Cement, liquid glass, colloidal silica, ammonium persulfate, hydrogen peroxide were used as the main hardeners. Samples were formed by mixing the original waste with astringent. The strength in time, shrinkage, resistance to water were studied. Samples formed on the basis of colloidal silica solution have a maximum uniaxial compressive strength of 0.4 - 0.5 MPa, on the basis of liquid glass—0.2 - 0.3 MPa. Adding fine sand increases the strength by 1.5 - 1.7 times. Samples based on ammonium persulfate and hydrogen peroxide do not have sufficient strength. Adding fine quartz sand increases the strength up to 1.0 - 1.2 MPa.

This study introduces a novel geotechnical composite material comprising two types of fill material sourced from the paper industry-deinking paper sludge ash (DPSA) and deinking paper sludge (DPS). Five composites with different DPSA and DPS contents were investigated. Two composites were selected for further analyses. The technology and procedure for composite installation were implemented in field tests. The composites with 80% and 70% DPSA exhibited the elasticity required to withstand minor landslide slip deformations, in addition to achieving sufficiently high values of uniaxial compressive strength. The composites had a low maximum dry density value, which led to fewer settlements in the entire support structure. The enhanced shear characteristics can enable the construction of a thinner retaining wall. The delay between preparation and installation of the composites was further investigated. The field tests confirmed that the composites with 80% and 70% DPSA can be installed on the construction site 4 h and even 24 h after mixing. In 2018, a retaining wall structure with 70% DPSA and 30% DPS was successfully implemented near a railway line using conventional technology as followed-up research to the herein presented study. Results have been derived from work performed in the scope of the H2020 Paperchain project in which novel circular economy models centered on the valorization of the waste streams generated by the pulp and paper industry as secondary raw material for several resource-intensive sectors, including the construction sector, have been developed. Environmental benefits are savings in natural raw materials, reduction of landfill disposal as well as CO2 emission reduction. Nasl. z nasl. zaslona. Opis vira z dne 16. 11. 2021. Št. članka 22363. Bibliografija: str. 12-13. Abstract.

This study evaluates the efficacy of using textile waste blended with paper waste to form biodegradable seedling pots. A bio-composite blend of cotton (20% cotton, 40% newspaper, and 40% corrugated cardboard) and polycotton (20% polycotton, 40% newspaper, and 40% corrugated cardboard) with an optimum strength was formed into seedling pots. The appreciated seedling pots (untreated blends of cotton and polycotton) were compared with the commercial pots (cardboard seed starter pot and Jiffy pot) in terms of mechanical properties (tensile strength and compressive strength), biodegradability (soil burial test and anaerobic digestion), and seed germination. The untreated blends of cotton and polycotton pots demonstrated a comparable optimum strength, while the Jiffy pot and cardboard seed starter pot obtained the least tensile and compressive strengths, respectively. The anaerobic biodegradability assay suggests that the cotton blend pot, polycotton blend pot, and cardboard seed starter pot can degrade anaerobically because of high biogas and methane generation potential. A 100% seed germination was observed from the four seedling pots tested. Thus, the results demonstrate the efficacy of utilizing textile waste and paper waste to develop seedling pots with desirable strength and biodegradability compared to the commercial pots.

New alternatives to plastic straws are being considered due to consumer demands for sustainability and recent changes in government policies and regulations, such as bans on single-use plastic products. There are concerns regarding paper straw quality and stability over time when in contact with beverages. This study evaluated the performance and properties of commercially available paper straws and their counterpart plastic straws in various intended applications. The physical, mechanical, and compositional characteristics, as well as the liquid interaction properties of the straws, were determined. The paper straws were composed mainly of hardwood fibers that were hard sized with a hydrophobic sizing agent to achieve a contact angle of 102° to 125°. The results indicated that all the evaluated paper straws lost 70% to 90% of their compressive strength after being in contact with the liquid for less than 30 min. Furthermore, the paper straws absorbed liquid at approximately 30% of the straw weight after liquid exposure for 30 min. Increased liquid temperatures caused lower compressive strengths and higher liquid uptake in the paper straws. This report provides directions and methods for testing paper straws and defines current property limitations of paper straws relative to plastic straws.

In this work, the utilization of waste paper in the preparation of cellulous-based composite is described, with latex as a binder. Paraffin wax and acrylic woven fibers were also used at various weight ratios to get the best mechanical and physical properties. The results were compared with the performance the Dixon, regularly used material in shoes manufacturing. The following tests were performed: compression resistance, density, water absorption, shrinkage, and moisture content. Manual method was employed in the preparation of test specimens in addition to laboratory forging machine for finishing of the specimens. Results of compression test (Modulus of elasticity, compressive strength, resistance to crushing) of the Specimens that contain pulp paper and reinforced with latex and acrylic fibers and low content of paraffin wax showed the highest resistance to compression, The increase of additives contents within the mix resulted in an increase in density. To mimic the real application conditions of the insole, the specimens were subjected to water absorption test by irrigation for 2 hours. The best specimen compositions for the water resistance test are those with high (5-10%) wax content due to the fact that the wax is a water repellent material. The shrinkage is another important parameter for the use of the composite in shoe industry. Result of shrinkage and humidity of all specimens show comparable results to commercially available and Dixon are also very close to the requirements of the specification of leather industry. However, in comparison with the available carton and dixon, our specimens contain from weight fraction (50g) waste pulp, (20g) latex, (4g) paraffin wax, (0.7g) acrylic fibers, proved comparable performance.

This study's focus was to develop a potential pathway for recycling of the paper mill sludge compost (PMSC) in brick making. Composting reduces the paper mill sludge (PMS) moisture content considerably and shredding becomes easier. The addition of PMSC leads to an increase of porosities in bricks and makes them lighter, besides delivering energy to the firing process from burning organics. Lighter construction materials help minimize construction outlay by reducing labour and transportation costs and lesser expense on foundation construction. The variability in the experimental data and the brick properties were investigated for two types of soils, typical in the brick industry of India (alluvial and laterite soil), blended with PMSC in five mix ratios (0%, 5%, 10%, 15% and 20%). The samples of oven-dried bricks were fired at two different temperatures (850 and 900 °C) in an electrically operated muffle furnace representing typical conditions of a brick kiln. Various properties of bricks were analyzed which included linear shrinkage, bulk density, water absorption and compressive strength. Conclusions were drawn based on these properties. It was found that the addition of PMSC to the alluvial and laterite soil by up to 10% weight yield mechanical properties of fired bricks compliant with the relevant Indian and ASTM codes. Toxicity characteristic leaching procedure (TCLP) tests showed that PMSC incorporated fired bricks are safe to use in regular applications as non-load-bearing and infill walls. This study is timely in light of the European Green Deal putting focus on circular economy. Besides, it fulfills the objective of UN sustainable development goals (SDG). © 2021 Elsevier Ltd

Building bricks were produced by utilizing deinking paper mill sludge (DPMS) and alluvial soil by varying percentage of sludge at different firing temperatures. Different mix proportions were prepared with 0%, 5%, 10%, 15%, 20%, 25% and 30% of DPMS incorporation in alluvial soil by weight. Three firing temperatures of 900 °C, 950 °C and 1000 °C were investigated to simulate the typical condition of kiln. The density, firing shrinkage, water absorption, efflorescence, apparent porosity, compressive strength and thermal conductivity of the bricks were determined. The XRD and microstructural analysis of brick specimens were also studied. The optimum firing temperature was 950 °C. The thermal conductivity decreases with increase in percentage of deinking paper mill sludge. It was found that 15% deinking paper mill sludge gives optimum strength at firing temperature of 950 °C. Developed bricks satisfy the requirements of class 10 of Bureau of Indian Standards (BIS), in terms of efflorescence, compressive strength and water absorption. Thermal conductivity results show that the developed brick was thermally more insulated than the conventional bricks and can be used as alternative to conventional bricks. This will address the issue of waste management through cleaner production and show the ways towards sustainable, economical and energy efficient construction.

In recent years, concrete in the construction industry has rapidly increased worldwide, including developing countries like India. The raw materials required to produce such a quantity require huge depletion of natural resources. On the other hand, disposal of paper waste, fly ash, and plastic waste is one of the biggest problems faced by many countries, including India, the amount of waste collected and recycled is less compared to disposal quantity. The use of these wastes in concrete reduces the disposal of waste in nature. In this experiment work, the use of these wastes in the concrete has been studied. Preliminary tests like specific gravity, fineness modulus, and water absorption have been carried out on the materials. Various mix designs are prepared by partial replacement of cement with fly ash and paper pulp, and sand is completely replaced with the quarry dust, and coarse aggregate is replaced with shredded plastic waste to create sustainable concrete. A comparative study on the properties like slump cone, the weight of the cubes, compressive strength and split tensile strength, and feasibility of such concrete has been carried out. Results indicated that the weight of cubes started to decrease with the addition of waste. Compressive strength and split tensile strength show that the strength started to fall with the addition of plastic. The cost of concrete decreased with the addition of waste. 5 % of plastic waste in concrete and 3 % of paper pulp, and 5 % of fly ash is considered the optimal replacement percentage.

In this paper, we report the performance of paper pulp as an innovative viscosity modifying admixture (VMA) for cement composites. Two different levels of fineness were obtained by mechanical milling of the same source of paper pulp. Their effects on viscosity modification, hydration kinetics, autogenous shrinkage, and compressive strength of cement grouts were measured, and their structural integrity at high pH was assessed. A new parameter was proposed to quantify nonlinearity induced by VMAs. Results showed that the hierarchical structure of paper pulp makes it possible to activate bridging flocculation and swelling mechanisms of hydrophile paper pulp fibers at different levels to produce versatile VMAs. The coarser milled paper pulp fibers mainly influences the plastic viscosity. By contrast, the milled paper pulp consisting of ultra-fine fibers significantly modifies both plastic viscosity and dynamic yield stress, induces more nonlinearity in the mixtures, and increases compressive strength of mortars at low dosages.

This paper deals with the valorization of waste paper fly ash (WPFA) as a binder for soil stabilization. The mineralogical characterization shows the presence of free lime, as well as some non-reactive and cementitious phases. The hydration of lime is an expansive reaction and can be problematic in soil stabilization. Therefore, to study its effect on stabilized soil, an in-house experimental set-up is proposed to measure the possible expansion. Furthermore, to study the effect of water reduction and delay time on strength, unconfined compressive strength with different mixes is conducted. The obtained results showed that using WPFA causes expansion in stabilized soil, but a delay time of 30 min, after mixing the material with water and then compacting it, can decrease the expansion. Additionally, decreasing the water content by a point of Proctor can be essential for improving the strength in soil samples, even reaching the same strength values as control samples cured at 7 days. Finally, all the results obtained in this study have shown that WPFA is a suitable material for use as a binder for soil stabilization while reducing its optimum water content, adding a proper delay time, and taking into consideration WPFA&rsquo, s expansive behavior at the moment of its use.

Among the largest producers of waste, the paper industry stands out due to its impact on human health and ecological balance. However, these residues may also contribute to a more environmental friendly brick industry, since the incorporation of fluxing agents may improve the firing process and the induced porosity reduces thermal conductivity of fired bricks. Therefore, this study aims to assess the feasibility of replacing clay with solid paper residue (PPR) from 2.5 to 17.5% in order to reduce resources depletion and improve brick performance. The original clay was characterized as a non-calcareous red clay with high contents of kaolinite. Several samples were made by extrusion and fired at 900 °C in accordance with industrial procedures. The addition of PPR led to increase shrinkage from 5 to 10% due to the effect of fluxing oxides which reduced pores volume and enlarged pores size. In addition, the impervious fraction was slightly reduced while the apparent porosity certainly increased (i.e. approx. 17%) due to the macroscopic pores developed by PPR combustion. This porosity produces lighter bricks (i.e. density decays from 1.76 to 1.39 g dm−3) with lower thermal conductivity (i.e. from 5.53 to 0.41 W m−1 K−1) but also reduces compressive strength (i.e. from 11 to 3 MPa) and increases water absorption (i.e. up to 24%). Nevertheless, toxicity is below the regulatory limits in all cases and fired bricks are easily adaptable to industrial procedures. It must be noticed that this work was supported by the Chilean National Commission on Research and Development (CONICYT) [grant number FONDECYT REGULAR 1180414]. Technical and human support provided by CICT of Universidad de Jaén (UJA, MINECO, Junta de Andalucía, FEDER) and by Centro de Manejo de Residuos y Energía (BIOREN) Universidad de la Frontera (Chile) are gratefully acknowledged.

Madagascar undergoes, like all countries in the world, the effects of climate change. in fact, since the last 5 years, in the coastal regions and the basins, the temperature has raised from 2 to 2.5 ° and varies between 34 to 36 ° in the shadow during the rainy season and on the high hills, the temperature diminishes from 2 to 2.5 ° during the dry period and varies from 4 ° to 8 °. However, the structure of lodging of 60% of the people are not adapted to this temperature change. Particularly, in the coastal regions, the walls of the houses are made of sheet iron. The inside of these houses is very hot when the weather is hot and very cold when it is cold. The inhabitants can’t afford the houses made in bricks or breeze block and the natural sources of aggregates are in the process of exhaustion. In the other part, we have seen that tons of paper are ready to be burned at the administrative services (public treasury, public financing, universities, ...) and the newspaper publishers. So, it becomes a must to find another way to the construction materials, justifying in that case our research axis. This study aims at the developing of construction material based on recycled paper, binder and aggregate. It deals of picking up or gathering all waste of papers and outdates newspapers and transforming them into brick for building constructions. What’s more, papers have prominent thermal insulating properties. Our work is focused on the study of variants on the different manufacturing processes, the choice of binder, the preparation of the specimens with different binders and different dosages, the mechanical compression tests for different binders, the evaluation of thermal conductivity for different binders and the numerical simulation of the thermo mechanical behavior of samples. The result is a lightweight brick with good thermal insulation. Tests have also made it possible to declare that the material has acceptable mechanical properties : the compressive strength is 1.56 [N/mm2], higher than the value prescribed by the standard for lightweight concrete blocks for construction of 1.1 [N/mm2], the value of thermal conductivity is 0.114 [W/mK], ten times less conductive heat than concrete and it can replace glass wool for a double its thickness. The specific weight is 57.5 [kg/m2].The practical results were confirmed by finite element simulations.

Civil Construction Industry impacts significantly the environment, being one of the most critic factors related to elevated production of Civil Construction Residue (CCR). Among CCR produced, the Kraft paper package acquires notoriety, due their large use on material packaging, such as Portland cement and lime, then, present a high production rate and offer contamination potential, lack of collection logistics and nearly any reuse. In this scenario, the study and development of alternative constructive materials which applies the sustainability concept and CCR recycling have acquired great relevance in the sector. It is highlighted the residue incorporation on masonry soil-cement blocks, due its block are not submitted to the sintering process. Then, the present research intend to study adobe blocks mechanical properties based on soil-cement reinforced with cellulose fibers obtained from Kraft paper recycling. The bricks were confectioned with 7% Portland cement content and with 0%, 8%, 10% e 12% Kraft paper fiber addition, being submitted to compressive strength test, water absorption test, durability test with wetting and drying and retraction analysis. It was verified the confectioned composites presented as a viable and interesting alternative on technical and environment range. All studied researches presented null retraction and compressive strength increase on cracked state, toughness increase and good performance about durability.

The emphasis of the current study was on the calcination of lime sludge, performed at different temperatures from 650°C to 750°C, which consumes less energy as compared to the industrial pr...

Slaker grits (SG) and biomass fly ash (BFA), two waste streams generated in the pulp and paper industry, are commonly disposed of in landfills, a practice with a high economic and environmental burden. In this work, their individual valorization as fillers in a commercial screed mortar formulation was evaluated in order to achieve a more sustainable management practice. The waste streams were characterized in terms of true density, particle size and morphology, and chemical and mineralogical composition. The influence of their incorporation amount (5.0, 7.5, and 10.0 wt.% of the total solids) and pre-treatment (sieving and grinding) on the fresh (workability) and hardened state (density, water absorption by capillarity, and flexural and compressive strength) properties of the mortars were assessed. The results show that the addition of 10.0 wt.% of the SG after milling and sieving (

The application of cement in various fields of construction makes it a very important engineering material. However, it is very expensive and releases carbon dioxide gas into the atmosphere. Therefore, it is crucial to find cheap and environmentally friendly alternatives to cement. Waste paper pulp ash (WPPA) was found to be one of the most mature cement substitute materials. In this work, the physical and mechanical properties of cement mortar with WPPA as partial replacement of cement were experimentally studied to ensure that the resulting mixes has appropriate mechanical properties. Cement mixes containing various percentage replacements of WPPA (5%, 10%, 15% and 20%) were prepared, and basic properties such as compressive strength, flexural strength, shear bond strength, efflorescence and water absorption were determined and compared with the control mix (0%). The basic mechanical properties of cement mortar containing WPPA are enhanced until the percentage of WPPA reaches 10%. However, a further percentage of WPPA substitution causes the mechanical strength of the mortar to decrease. It is found that the optimal level of WPPA as a cement substitute is 5%. Although the physical properties of WPPA blended paste are improved with the increase of WPPA percentage. Our research provides a typical example of how the use of cement mortar containing WPPA can aid to the development of building materials. In addition to having better mechanical strength, cement-WPPA mixed mortar is a cost effective and environmentally friendly material.

In this study, the effects of the mixing conditions of waste paper sludge ash (WPSA) on the strength and bearing capacity of controlled low-strength material (CLSM) were evaluated, and the optimal mixing conditions were used to evaluate the strength characteristics of CLSM with recyclable WPSA. The strength and bearing capacity of CLSM with WPSA were evaluated using unconfined compressive strength tests and plate bearing tests, respectively. The unconfined compressive strength test results show that the optimal mixing conditions for securing 0.8&ndash, 1.2 MPa of target strength under 5% of cement content conditions can be obtained when both WPSA and fly ash are used. This is because WPSA and fly ash, which act as binders, have a significant impact on overall strength when the cement content is low. The bearing capacity of weathered soil increased from 550 to 575 kPa over time, and CLSM with WPSA increased significantly, from 560 to 730 kPa. This means that the bearing capacity of CLSM with WPSA was 2.0% higher than that of weathered soil immediately after construction, furthermore, it was 27% higher at 60 days of age. In addition, the allowable bearing capacity of CLSM corresponding to the optimal mixing conditions was evaluated, and it was found that this value increased by 30.4% until 60 days of age. This increase rate was 6.7 times larger than that of weathered soil (4.5%). Therefore, based on the allowable bearing capacity calculation results, CLSM with WPSA was applied as a sewage pipe backfill material. It was found that CLSM with WPSA performed better as backfill and was more stable than soil immediately after construction. The results of this study confirm that CLSM with WPSA can be utilized as sewage pipe backfill material.

The potential to use dredged sediment from the Watsongpeenong Canal and paper mill residue as the primary raw materials for producing facing bricks was studied in the laboratory. Dredged sediment and paper mill residue were chemically, mineralogically, and thermally characterized using X-ray fluorescence (XRF) and X-ray diffraction (XRD). To evaluate the effects of the contents of the paper mill residue on pore-forming, large amounts of paper mill residue, ranging from 5 to 7 % by mass, were blended with dredged sediments and fired at 700oC. The physical-mechanical properties, including dimensions and tolerances, wryness, deviation of the right angle, water absorption, compressive strength, stain, hole, rails, and cracks, as well as the microstructural properties of the facing bricks, were investigated. In addition, the heavy metals (Mn, Pb, Cd, and Cr) in the facing bricks were identified. The results indicated that the dimensions and tolerance, wryness, deviation from the right angle, water absorption, compressive strength, holes, and rails of the facing bricks with 5 % and 7 % by weight of paper mill residue were compliant with the requirements of the TIS 168-2546 standard. For stains and cracks, no batches of the facing bricks complied with the standard. Facing bricks made from 93 % dredged sediment and 7 % paper mill residue (93D+7P) obtained the highest compressive strength, with a value of 23.66 MPa. Therefore, dredged sediment and paper mill residue can be considered as suitable for use as primary raw materials in the production of facing bricks.

Residue generation causes significant environmental damages, mainly when there on technology for its treatment and several times end up discarded inappropriately. Several industries sectors have developed management programs aiming to destiny adequately solid residues produced on their activities. An alternative to solve this problem is the recycling process, which treats the residues as a potential matter to produce new products, focusing to reduce environmental impacts and inappropriate residue discard. In this context, ecological bricks emerge as a great opportunity to recycle, permitting residue incorporation. The present research analyzed compressive strength, retraction and water absorption on adobe bricks, made of soil-lime mixture and reinforced with Kraft paper fibers. Blocks were made with 7% lime content and with 0%, 8%, 10% e 12% fiber addiction. The results demonstrated that soil-lime-fiber blocks, with indicated lime content and fiber addiction, did not presented results that satisfy normative criteria to be used as a innovative material.

A novel method was introduced to evaluate the quality of fiber material from paper for recycling. The new concept, fiber integrity value, its components, and its relationship with paper strength properties were examined in more detail. The effect of deinking and screening on fiber integrity value, and its component parameters was shown. The fiber integrity value is closely connected to the strength potential of the pulp. It was shown that when the bonding degree was also considered, there was very good correlation with the tensile strength, tensile stiffness, and compressive strength (SCT) values. The fiber integrity value concept can be determined based on data from in-line analyzers.

Waste management and recycling of wastages play an important role in having a sustainable city or eco-city. Rapid increasing population in some cities of the world and especially in developing countries cause a different kind of pollution such as air, water, noise, visual, etc. Wastages are directly associated with city contamination. Useful policies for recycling waste can reduce pollution and boost the economy of a country. This study investigates the influence of recycled concrete aggregate (RCA), Silica fume (SF), and paper sludge ash (PSA) on the workability, compressive strength, and acoustic emission behavior of concrete. 5 and 10% of cement were replaced by PSA and silica fume and 10 and 20% of coarse aggregate was replaced by the recycled aggregate. PSA and SF improved the Strength, and acoustic emission behaviors of concrete, moreover, the recycled aggregate also improved the properties of concrete.

The paper production is developed throughout the world, therefore, more paper sludge waste (PSw) is accumulating. The aim of this work was to determine the properties of PSw burned at 900 °C and its impact on physical–mechanical properties of cementitious matrix and evaluate its usage/utilization possibilities in cementitious materials. For the implementation of the aim, cement-based specimens were prepared and their –mechanical properties were determined. Specimens from five compositions were formed, with 2.5%, 5%, 7.5%, and 10% of the cement by weight replaced with PSw. When 5% of the cement was replaced with PSw, the compressive strength increased by approximately 7%, although density and ultrasound velocity slightly decreased (up to 1.5%). When 7.5% PSw was added, the compressive strength of the specimens decreased. To summarize, it can be stated that up to 5% PSw may be utilized/used for the preparation of cementitious mixtures. The usage of the waste allows environment conservation, reduced amount of cement in mixtures, and improvement of properties of cementitious materials., This article belongs to the Proceedings of Innovations-Sustainability-Modernity-Openness Conference (ISMO’19), Bialystok, Poland, 22–23 May 2019

Paper waste sludge (PWS) is the main and the greatest by-product in paper production process, and its elimination as well as destruction is a primary environmental problem. This research explores the feasibility of such wastes to be used in polyurethane foam composites. It is well known that using water as a sole blowing agent has major drawbacks such as long demould time, shrinkage, high diffusion rate of carbon dioxide and etc.; therefore, the bio-based propylene glycol (RPG) is used in order to solve such problems. The addition of 20 parts by weight (pbw) of RPG eliminates the primary shrinkage of the foam composites when PWS is used in the amount varying from 5% to 20%, and improves the dimensional stability at 70 oC and 90% relative humidity conditions. The addition of titanate coupling agent modified PWS particles increases the compressive strength of the final composites from ̴ 26% to ̴ 53%, from ̴ 17% to ̴ 31% and from ̴ 3% to ̴ 23% for, respectively, 10 pbw, 15 pbw and 20 pbw RPG extended foam composites.