Problematic soils, especially clayey soil, are problematic for engineering projects in their natural state because of clay's swell-shrinkage phenomenon. Numerous methods and stabilizer materials have been used to enhance clay's geotechnical properties and make them appropriate for construction. One of the significant methods of stabilization of problematic soil is using waste materials like waste glass, waste stone, waste plastic, etc. Due to the waste stone's consistency reducing water content and increasing the soil's strength, it has been employed in many civil engineering studies. Waste stone is available in various forms, including waste stone powder (WSP). WSP is produced by blasting tunnels or cutting huge stone blocks. Hence, the main aim of this study is to review the influence of WSP on improving the geotechnical properties of problematic soils treated with WSP, for this purpose, the treated problematic soils with various percentages of WSP are compared with natural soils. This study evaluates physical properties (i.e., Index properties, linear shrinkage/swelling, optimum moisture content, and maximum dry density) and mechanical properties (i.e., unconfined compressive strength and California bearing ratio). Also, the effect of WSP on decreasing the thickness of pavement layers was reviewed
Since concrete is one of the most popularly utilized building mixtures in construction, a high demand of natural resources is significantly emerged. Therefore, a skyrocketed attention has been paid to create new opportunities for the use of recycle materials to develop a new construc-tion substance with more satisfactory properties. The use of waste products in concrete is not only economical, but it helps in solid waste management as well. Among various properties of concrete, thermal conductivity is a crucial factor that plays an important role in in building insu-lation by evaluating a material's capacity to transfer heat. This paper aims to review the potential application of waste materials in concrete as additive ingredients and investigate the effect of this waste material on thermal conductivity of concrete. The review of literature revealed that the application of most of the waste materials exhibited an obvious potential as thermal insulator. However, further investigated work is needed to highlight the advantages of utilizing waste mate-rials in concrete containing various type of waste materials
Due to the expansion of industrial operations globally in recent years, waste output has risen. So these wastes must be reduced by recycling and reusing to achieve environmentally friendly buildings and find various alternative materials in critical cases. The statistical indicators are used as practical study including Multiple linear regression (MLR) and artificial neural network (ANN) models. The study's goals were to assess the effectiveness of granite waste (GW) as a replacement for cement, sand, plastic, and binder in specific building applications and the relationships between MLR and ANN approaches. Results show the efficiency of adding granite waste to some construction stages and replacing it with cement in the mixture and examining its strength, it gave excellent results in addition to good results for its use as a binder in cement mortar, while the results were weak when used as a substitute for sand and plastic in insulator because it's classified as fine sand, Therefore, it cannot be used as a substitute for sand in the construction. The statistical models give an effective indicator to use GW as an alternative material ( binder and cement) based on the coefficient of correlation (R2) for the two models MLR and ANN equal to 83.4 % and 80 % respectively.
Thousands of tons of marble waste can be reused every year in Iraq. Few investigations are made to study the effect of marble as a filler on hot mix asphalt concrete.. This big amount of waste has a bad effect on the environment and needs a lot of money and effort for recycling or disposal. Lime stone dust was used as a control filler. The laboratory tests have been conducted in order to evaluate the properties of each type of filler, which consist of the grain size distribution, the specific gravity (Gs), specific surface area (SA), pore volume(PV), mineral composition, pH and chemical composition.To study the effect of SM on the performance of HMA mixture, several tests were made consist of Marshall stiffness, Indirect tensile strength, Moisture susceptibility and Creep tests. Many conclusions were achieved referring the importance of using Sulaimania Marble waste (SM) in the enhancing most of the properties of HMA concrete.
The impact resistances of concrete slabs have a different volume fraction replacement of waste plastic aggregate has been examined in this study as a fine aggregate as: 0% (reference), 10%, 20% and 30%. These tests include the splitting tensile, density, compressive strength. Also, the (ultrasonic pulse velocity tests) was carried out. Repeated falling mass was used in order to carry out the low-velocity impact test in which a 1300 gm steel ball was utilized. From a height of 2400mm, the ball falls freely on concrete panels of (500×500×50 mm) with a network of waste plastic aggregate. As per the results, a prominent development was seen in the mechanical properties for mixes involving polyethylene aggregate up to 20% as compared to the reference mix. A significant development was seen in low-velocity impact resistance of all mixes involving waste plastic fine aggregate as compared to reference mix. As per the results, the greater impact resistance at failure is offered by the mix with (20%) waste plastic aggregate by volume of sand than others. The reference mix increased by (712.5%).
The Organo modified and unmodified sodium montmorillonite clay effect on thermal and mechanical properties of the waste low density polyethylene (wLDPE) were studied. Commercialize unmodified (MMT) and Organo-modified clay (OMMT) were added to the wLDPE to prepare wLDPE-clay noncomposites by melt intercalation method. OMMT and MMT were added in a range of 1-5 wt %. Fourier transform infrared spectroscopy (FTIR) used to evaluate polymer structure before and after the fabrication. Thermogravimetric analysis (TGA) and Differential Scanning Calorimetry (DSC) were used to analyse the thermal stability and thermal properties for the wLDPE and fabricated nanocomposites. Tensile mechanical characteristics of the waste specimens before and after nanocompsite fabrication were evaluated. The FTIR exhibited no change in the chemical structure of the wLDPE used after clay addition. Melting temperature and crystallization percentage were increased up to 1 wt% loaded and decreased in with clay content increasing when compared to the original waste matrix. The thermal steadiness of the wLDPE /clay nanocomposites were found enhanced in the case of loading 3 wt% of OMMT. The elastic modulus has improved in the 3% OMMT loaded.
The thermal and acoustic isolation properties of unsaturated polyester composites reinforced by palm waste filler have been experimentally investigated. The composites have been prepared using hand lay-up technique with filler weight fraction of (0%, 3%, 5% and 7%). Three types of palm waste that (Date seed, old leaf bases and petiole) were ground and sieved separately to produce the filler with particle size ≤ 400µm. Thermal conductivity, thermal diffusivity, and specific heat capacity were examined using Hot Disk thermal analyses. The acoustic isolation property examined in a sound-insulated box. The experimental results show that the thermal conductivity and thermal diffusivity of the composite specimens reinforced by seed or old leaf bases filler increased with increasing the fillers weight fraction. While increasing the petiole filler decreased the thermal conductivity and thermal diffusivity by 19% and 40% respectively at 5% weight fraction as compared with a pure unsaturated polyester material. So, the composite reinforced with petiole filler has improved the thermal insulation properties. The composites samples reinforced with palm waste show higher sound absorption in compared to the pure unsaturated polyester material. The sound absorption properties of composite reinforced with 7% old leaf bases filler improved by 15% and 23% at low and high frequency respectively rather than of pure unsaturated polyester material.
This investigation was conducted to assess the efficacy of some environmental conditions of soil specimens stabilized with optimum waste lime content 6%. These conditions are represented by cycles of (wetting-drying-freezing), (wetting-freezing-drying), (drying-wetting-freezing), (drying-freezing-wetting), (freezing-wetting-drying) and (freezing-drying-wetting). The soil specimens were subjected to these conditions, the durability of these specimens is study by knowledge the change in unconfined compressive strength, volume change and loss in weight. The results indicated that the unconfined compressive strength decreases with cycles for all conditions, but for different percentages according to the type condition. Where the condition more effect that starting freezing-drying-wetting. Also the results show that the specimens subjected to cycles of (freezing-drying-wetting) and (wetting-freezing-drying) destroyed at the end of eight cycle, but the specimens were subjected to other conditions destroyed at the end of tenth cycle. The results show that the maximum loss in weight for specimens subjected to cycles starting wetting-freezing-drying, and the maximum value of volume change for cycles starting freezing-drying-wetting. Finally these condition are regarded very severe conditions and effect on durability of soil stabilized.
During the last years, several researches have been studying the final disposal of tyres wastes, due to the great volume generated worldwide, as well as the difficulty for discarding the disposal sites which become a serious environmental problem. In spite of this, recycling appears as the best solution for disposing tyres residues, due to its economical and ecological advantages. This research carried out to assess the feasibility of using crumb rubber (the product of shredding used rubber tyres) as a partial sand replacement in foamed concrete, and investigates the effect of it on some properties of foamed concrete such as, density, water absorption, compressive strength, tensile strength, flexural strength and impact resistance. Crumb rubber of tyres ranging from (0.7 to 5mm) in size was used in this research. Three proportioned mixes were designed in this research, have the same cement content, water-cement ratio, and foam content. The first mix represents a typical reference formulation of foamed concrete without crumb rubber (FC). In the others mixes (FCR-1 and FCR-2), respectively, 20 and 30% of volume of sand were replaced by crumb tyres rubber waste. Tests carried out to assess the behaviour of final product. The results obtained were demonstrated decreasing in foamed concrete strength (compressive, tensile, flexural, and impact) with the increasing of crumb tyres rubber content in the mixture and rubberized foamed concrete specimens (FCR-1 and FCR-2) show a cohesive behaviour than the specimens of reference mix (FC), especially in tensile strength. Comparing with the reference mix (FC), at an age of (28 days), the decreasing of compressive strength was (20.85%) for (FCR-1) and it for (FCR-2) was (37.76%).
This research focuses on studying the impact of different sources of wastewater, such as do-mestic, industrial, agricultural, etc. upon groundwater. The swamp of contaminated water collec-tion within the Al-Anbar University area was taken as a case study for this research. This swamp has a pond that works as a collection basin for different sources of wastewater mainly domestic waste coming from leakage of contaminated water from the septic-tank of the residential com-plex of students. This contaminated water will leak over time within the folds of soil due to per-meability and the effect of land attraction and reach the levels of groundwater.The presence of polluted water near groundwater is an environmental hazard and harmful because this leakage water has different diseases and germs, which could pose a danger to human health. Different samples of these sources were taken from different places at different times and some physical, chemical, and biological tests were then conducted. Wastewaters characterization was also investigated in this study to make an assessment for water quality and find out a proper treatment method. Data obtained from this study show different levels of pollutants, which could highly affect groundwater quality. A proper and advanced treatment method was also proposed in this study, depending on the wastewater characterization results. The purpose of this research is wastewater treatment using the physical method with coagulation and Flocculation processes with local coagulants to reduce pollutants impact on groundwater.The results showed the addi-tion of alum at 35 mg/l increased the removal efficiency by 80.7% at the settling time of 60 min, and the addition of 35 mg/l of the lime increased the removal efficiency by 63.9% at the same settling time.It has been proven that the use of alum is more effective than lime for sedimenta-tion suspended matter. The optimum dosage and settling time are 20 mg/l and 60 min respec-tively.
The presented work investigates the effect of addition admixtures (superplasticizer and polymer) to Chopped Worn-Out Tire concrete as a partial replacement of cement weight. Superpasticizer was addition by 4% and polymer (SBR) by 15%. The Chopped Worn-Out Tire (Ch.W.T.) addition to reference concrete with the three proportions as a Partial Replacement Ratio (PRR) of (25,25),(20,30),and (30,20) by volume of (sand and gravel) respectively. Three mixes were selected with above PRR for each type of admixture in additional to three mixes for Ch.W.T. concrete without admixtures and three reference mixes with admixtures without Ch.W.T. Thus, twelve mixes could be used in this investigation. Compressive strength and modulus of elasticity (static and dynamic) were tested. The test results indicated that the use of admixture led to significant improvement in concrete properties in general. Superplasticizer gave best results comparative with polymer, for example at 28 day the compressive strength of superplasticizer Ch.W.T. concrete Csp25,25 was 32.5 MPa, while compressive strength of polymer modified Ch.W.T. concrete CB25,25 was 28 MPa and compressive strength of Ch.W.T. concrete C25,25 was 21.2 MPa.
The white cement Kiln dust (WCKD) is a secondary production from the cement industry through its production operation. Environmentally, it is considered as an unwanted waste because it causes air pollution and ground congealment, and it is needed great efforts and financial support to disposal it. In this study, the WCKD was used partially instead of limestone as a filler in the asphalt mix, where it was used by ratios of 0%,25%,50%,75% and 100% from the weight of limestone. An evaluation of the mechanical characteristics was conducted by carrying out Marshall test and Indirect Tensile test, and the results showed that the increase in the WCKD percent reduces the asphalt mix density and increases the percentage of air voids, while the other characteristics (stability, Marshall Stiffness, flow and Indirect Tensile Strength) increase when the WCKD ratio is 25% and 50%. These those characteristics start decreasing when the WCKD ratio was 75% and 100%. The study showed that the optimum ratio of the WCKD is 50% from the limestone weight, and the WCKD cannot be used as a filler entirely in asphalt mix, but it can be used partially.
Agricultural, industrial, and household debris can be employed as biosorbents to extract heavy metals from water that has been contaminated. Kitchen waste includes, among other things, peels from promotional gates, lemons, avocados, apples, kiwis, watermelons, and onions. Moreover, coffee and tea grounds are considered to be household refuse. This review illustrates the scholarly investigations that explored the potential of various waste materials as adsorbents for wastewater treatment. An extensive array of experiments was conducted to determine the variables that influence the capacity of these materials to adsorb heavy metals. To undertake the experiments above, different concentrations of biosorbent were introduced into the effluent at various contact times and pH levels. The researchers investigated the effects of varying these parameters and found that the biosorbent's ability to adsorb heavy metals is directly proportional to these factors. The results and conclusion indicated that the impact of biosorbent concentration and contact duration on the pH of contaminated water was assessed. To encourage the incorporation of industrial, agricultural, and household refuse into water treatment processes rather than permitting it to accumulate as an environmental hazard.
This research paper is an attempt to reuse plastic waste fibre resulting from plastic sections industry as an additive to concrete matrix. The relationship between fibre volume fraction and mechanical properties of concrete and re-inforced concrete tiles was investigated. Three volume fractions of fibre ( 0.5 % , 1 % and 1.5 % - by volume of concrete ) were used through the experi-mental program. Tests’ results proved a slight decrease in concrete compres-sive strength as plastic fibre was added compared with the reference mix. Flexural behaviour of concrete tiles was enhanced as adding fibres. Adding fibre to Concrete results in a negligible reduction in concrete density. Fibre with high volume fractions improved Splitting tensile strength compared to the reference mix.
This study aims to investigate the durability properties and microstructural changes of self-compacting concrete (SCC) incorporating waste polyethylene terephthalate (PET) as fibers and as fine aggregate replacement. This is after exposed to saline environment (Alkalies, Sulphates, and Chlorides). PET effect into two forms was also evaluated for routine rheological properties of SCC and mechanical strength before and after exposure to sulphate salt. Five proportions of each form of PET incorporation in SCC mixtures were utilized. The volume fractions considered for PET as fibers were (0.25, 0.5, 0.75, 1.0, and 1.25)% by volume, with aspect ratio of 28%, and (2, 4, 6, 8, and 10)% by volume for fine aggregate replacements. Results indicated that the inclusion of PET adversely affected fresh propertis especially high proportions of PET as fine aggregate. Alkali silica reaction (ASR) outcomes illustrated an enhancement in the mix containing PET fibers, while fine-PET mix was slightly enhanced. Magnesium sulphate reduced mass and compressive strength of all mixes in percentages ranging from (0.18-0.90) % for mass loss and from (0.47-55.13) % for compressive strength loss. Ultrasonic pulse velocity (UPV) and dynamic modulus of elasticity (Ed) increased due to the sulphate impact except for M0.5 and M10 which decreased in both tests. Chloride's theoretical and modelled results illustrated higher diffusion coefficients and lower surface chloride content of fiber-PET mixes as compared to fine-PET mixes. The predicted SCC cover depths for fiber-PET mixes were lower than those predicted for fine-PET mixes for 20 and 50 years of service life design.
Scientists have recently started looking for new ecologically friendly and sustainable materials. Construction materials are among the numerous widely employed materials, and it is normally acknowledged that they have an apparent detrimental influence on the environment. Thus, the contribution of this paper is to describe the palm frond natural fibers' effect on concrete's mechanical characteristics. Since concrete is a brittle material, the goal of this research is to increase the tensile strength of concrete by using organic fibers (palm frond fibers), a waste product. In order to determine the ideal percentage of fibers, the following percentages were tested: 0.25, 0.5, 0.75, and 1% by volume of concrete. On dry density, compressive strength, and tensile strength, the impacts of fibers were investigated. The density of concrete decreased with increasing fiber ratios. The compressive strength slightly decreased, while the splitting strength significantly improved. According to the results, the best amount of palm frond fibers that can be add to concrete is 0.75% by volume.
This study aims to improve different properties of sustainable self-compacting concrete SCC containing treated and modified polyethylene terephthalate PET fibers. For this purpose, gamma ray surface treatment and geometric modification were utilized for the used PET fibers. Concrete fresh properties include slump flow, T500mm, L-box and sieve segregation while mechanical properties include compressive, split tensile strength, flexural strength, static modulus of elasticity and impact strength. Further, physical properties and related durability properties comprise dry density, ultrasonic pulse velocity, porosity and water absorption. The results obtained demonstrated that the treatment and the modification used for the PET fibers slightly reduced the fresh properties of produced sustainable SCC (slump flow, T500 mm, L-Box and sieve segregation). However, they were within the limits of the SCC specification as reported in EFNERC guidelines. Further, concrete hardened properties in terms of compressive strength, splitting tensile strength, flexural strength, modulus of elasticity, impact strength, ultrasonic pulse velocity, decrease in the dry density, decrease in porosity and water absorption increased significantly.
The presented work investigates the effect of addition admixture (cement kiln dust) to concrete as a partial replacement of cement weight. Cement kiln dust was added by (10,30,50)% of cement weight.Four mixes were selected, three of them contain cement kiln dust (CKD) and one reference mix without any admixture for ages (7,28,90) days. Compressive strength ,flexural strength, ultra-sound velocity (UPV), slump, splitting tensile strength and static modulus of elasticity were tested.The test results indicated that the use of (CKD) led to significant decreasing in concrete strength in general and this decreasing increases with the increasing of (CKD), for example at 28 day the compressive strength of reference concrete (A) was 35 MPa, while the compressive strength of (B,C,D) contain (10,30,50)%CKD were (28,25,22) MPa respectively.
These systems show great promise by converting waste heat from photovoltaic modules into additional electrical power. The study analyzes the performance and efficiency of the hybrid PV-TEG systems under varying conditions, such as different solar concentration ratios, cooling methods, and materials. While these innovations promise to improve system efficiency, the review also identifies several challenges, including increased thermal resistance, higher system costs, and the minimal temperature difference across the TEG, which significantly limits its performance. This limitation, where the temperature differential is often too small to be effectively harnessed, reduces the TEG's overall efficiency and hinders the integrated system's potential gains. The review underscores the need for urgent and extensive research to develop optimized design configurations, durable mathematical models, and further experimental validation to ensure the practical viability of these systems under diverse environmental conditions. Despite these challenges, the potential of PV-TEG systems to revolutionize solar energy technologies is undeniable.PV-TEG performance is intricately linked to environmental conditions: higher solar radiation boosts efficiency, but increased ambient temperatures reduce it. TEGs often hinder PV cooling, yielding minimal efficiency gains. Non-uniform heat and low-temperature differences across TEGs further decrease performance. While hybrids can improve power conversion, high costs limit feasibility. However, with strategies such as enhancing solar concentration, using effective cooling methods like water or nanofluids, and advanced materials like phase change materials, the efficiency and reliability of these systems can be significantly improved
Flow of crude oil in pipelines suffers from a problem of fluid flow pressure drop and high energy consumption for fluid pumping. Flow can be enhanced using either viscosity reduction or drag reduction techniques. Drag reduction (DR) is considered as a most effective and most applicable method. The technique contributes in reducing the frictional energy losses during the flow by addition of little amounts from drag reducing agents. The present work focuses on preparation and application of a new natural and low cost material derived from palm fiber (PF) that has been tested as a drag reducing agent (DRA) for crude oil flow enhancement. This objective has been achieved through designing and constructing of an experimental rig consisting of: a crude oil pipe, oil pump, pressure sensors, solenoid valve and programmable logic control. The additive material (PF) is prepared with different diameters (75µm, 125µm, 140µm) and tested with different concentrations as: 100, 200, 300, 400, and 500 mg/L for reducing the drag inside the oil pipe. The experimental results showed that the fiber with 125µm diameter and 100ppm is the best where the percentage of drag reduction reached 43%. Furthermore, the results of this work proved that PF is an efficient and low cost DRA that can be applied successfully in crude oil pipelines as well as its contribution in the waste management.
Some mechanical properties of mortar (compressive strength and hardness) with sawdust replacement of sand were investigated. Cubes of 50 mm × 50 mm were prepared, the compressive strength tests were done for a replacement levels ranging (5, 10, 15, 25, 50, 75) % by volume a reference mix were also prepared for comparison this test was done after 7, 14, and 28 days while hardness test were done after 28 day for a replacement levels (0, 5, 10, 15, 25) % by volume. Result showed that the compressive strength of the specimen were decreased with higher sawdust content, hardness values were decreased slightly in the replacement levels 0, 5, 10 % while the values began to decrease noticeably in the replacement levels 15 and 25 % the hardness values were (59, 57.5, 56, 47.77 , 45.2) N/mm2 respectively A cost analysis was done, this analysis was based on a unit of mortar (1.0 m3) made from conventional materials and a modified concrete made by substituting materials with sand using sawdust
This investigation provides experimental results and nonlinear analysis by using finite element model of thick hollow core slab made from recycled lightweight material. Four hollow core slabs specimens were cast and tested in this investigation with dimensions (1200mm length, 450mm width and 250mm thickness). The crushed clay brick was used as a coarse aggregate instead of gravel. The iron powder waste and silica fume were used in order to increase the compressive strength of concrete. The techniques reduction hollow length and use shear reinforcement were used to improve shear strength and avoid shear failure. The specimens were tested by applying two-line load up to failure. The experimental results were showed these techniques were resisted the shear failure significantly and works to change failure mode from shear to flexural failure. Finite element computer software program (ANSYS) was used to analysis hollow core slabs specimens and compare the experimental results with the theoretical results. Good agreement have been obtained between experimental and numerical results.