Ash Ratio Research Articles

Influence of Chitin Nanofiber and Rice Husk Ash on Properties and Bearing Resistance of Soft Clay Soils

Use of soft clay soils in construction activities has faced many problems. Some improvement, stabilization, and reinforcement methods is required to use these soils in body of roads, sub-foundations and embankments. In this research, the effect of chitin nanofiber and rice husk ash as additives on the behavioral properties and bearing resistance of soft clay soils by considering the processing time of 7, 28, 42 and 90 days was investigated. The suitability of chitin nanofiber to be used as an additive was evaluated by FTIR, XRD and SEM analysis. Different percentages of additives (1, 2, 4, 6 and 8%) with variations in chitin nanofiber and rice husk ash ratio were added to soil containing 6% lime. Maximum reduction on liquid limit and plastic index was obtained by addition of 2% additives to the soil containing 6% lime in which the percentage of chitin nanofiber was more than rice husk ash. Using examined additives in clay soil resulted in to a significant increase in bearing resistance, specifically at higher percentages of additives and curing times (days). As a whole, obtained results confirmed the potential use of chitin nanofiber and rice husk ash as additives for the improvement of soft clay soils.

The Binder Index – A Parameter That Influences the Strength of Geopolymer Concrete

Abstract Geopolymer concrete (GPC) is an environmentally friendly material in the sense that it uses industrial by-products such as ground granulated blast furnace slag (GGBS) and fly ash (FA), which are activated by an alkaline solution. This paper presents an experimental investigation concerning the strength of the GPC and its relation to a new parameter called the ‘Binder Index (BI)’. The parameters considered in the investigation include GGBS to fly ash ratios (0.25 0.43, 0.67, 1.0, 1.5, and 2.3) and the molarity of the alkaline activator (6, 8, 10, and 12). The binder index combines the effect of the GGBS to the fly ash ratio and the molarity of the alkaline activator. The results have shown that the strength of the GPC is significantly influenced by varying the binder index. The results indicate that a nonlinear relation exists between the binder index and the compressive strength of the GPC and the binder index and the modulus of rupture.

Evaluation of the Effect of Breed and Line on Slaughter Value and Quality of Lamb Meat

The aim of our experiment was to evaluate to what degree carcass value and quality of lamb meat are effected by selected breeds (Zwartbles, Suffolk, Romney Marsh) and lines (Zbyšek, Ztepl, Záblesk, Ewebank Armani, President, Romeo, Avatar). Suffolk breed rams were found to have (p ≤ 0.05) the lowest weight at slaughter (37.47 ± 4.10 kg) and also carcass weight (15.23 ± 1.78 kg). Romney Marsh‘s carcasses had a significantly higher degree of fat cover (3.6 ± 0.4), kidney fat ratio was 0.78 ± 0.17 % and the percentage of fat from the right leg was 2.50 ± 0.61 %. The conclusively (p ≤ 0.01) highest ratio of the right leg was recorded in the Suffolk breed (17.00 ± 0.79 %). The highest ratio of the leg of carcass among the lines was found in the President line (17.53 ± 0.66 %). Meat of the Suffolk line had the significantly (p ≤ 0.01) highest ratio of dry matter, intramuscular fat, protein and ash. Among the lines, this trend was similar in favor of the Suffolk’s line. The Zwartbles breed had the lowest (p ≤ 0.01) ratio of fat and dry matter in the meat. The value of pH, lightness (L* = 51.55 ± 1.66) and color spectrum b* (13.12 ± 0.46) of meat was conclusively (p ≤ 0.01) the highest in the Zwartbles breed, while the redness indicator (7.56 ± 1.45) was conclusively the lowest for this breed. Statistically (p ≤ 0.01), the meat of the Suffolk breed had the most potent red color (a* = 11.87 ± 1.24) and the highest water‑holding capacity (81.57 ± 1.87).

Recycling of plastic waste into tiles with reduced flammability and improved tensile strength

This paper is focused on finding effective alternative for disposal of waste plastic bags by designing tiles with better mechanical strength, reduced flammability level, resistant against strong acids and bases and organic solvents, so that tiles can be used for designing structures for paver tiles for societal usage. In recent years the plastic consumption has increased manifolds leading to accumulation of plastic waste in large amount. Waste plastic bags being non-biodegradable and its extreme durability make its disposal process difficult. Plastic solid waste (PSW) present challenges and opportunities to the societies regardless of their technological advances and sustainability awareness. Traditional technologies for waste plastic disposal have failed to cope up with the increased generation of plastic waste. Also, the disposal of fly ash, waste by-product generated by combustion of coal in thermal power plants, is a serious problem both in terms of land use and environmental pollution. In this study, waste plastic matrix reinforced with fly ash (FA) and a flame retardant at different loadings (wt %) 5, 10, 15, 20 using twin screw extruder were molded into composite tiles and their characteristics were evaluated. Effect of different filler loading on waste plastic matrix was investigated. Composite (LFTP3) having appropriate ratios of fly ash and flame retardant showed reduced flammability with linear burning rate of 4.36 mm/minute and improved tensile strength of 9.68 MPa. Morphological and structural properties of all the composites were also investigated along with their flammability, resistance to different acids and bases and organic solvents, water absorption and mechanical strength.

A New Parameterization of Volcanic Ash Complex Refractive Index Based on NBO/T and SiO2 Content

AbstractRadiative transfer models used in remote sensing and hazard assessment of volcanic ash require knowledge of ash optical parameters. Here we characterize the bulk and glass compositions of a representative suite of volcanic ash samples with known complex refractive indices (n + ik, where n is the real part and k is the imaginary part). Using a linear regression model, we develop a new parameterization allowing the complex refractive index of volcanic ash to be estimated from ash SiO2 content or ratio of nonbridging oxygens to tetrahedrally coordinated cations (NBO/T). At visible wavelengths, n correlates better with bulk than with glass composition (both SiO2 and NBO/T), and k correlates better with SiO2 content than with NBO/T. Over a broader spectral range (0.4–19 μm), bulk correlates better than glass composition, and NBO/T generally correlates better than SiO2 content for both parts of the refractive index. In order to understand the impacts of our new parameterization on satellite retrievals, we compared Infrared Atmospheric Sounding Interferometer satellite (wavelengths 3.62–15.5 μm) mass loading retrievals using our new approach with retrievals that assumed a generic (Eyjafjallajökull) ash refractive index. There are significant differences in mass loading using our calculated indices specific to ash type rather than a generic index. Where mass loadings increase, there is often improvement in retrieval quality (corresponding to cost function decrease). This new parameterization of refractive index variation with ash composition will help to improve remote‐sensing retrievals for the rapid identification of ash and quantitative analysis of mass loadings from satellite data on operational timescales.

The Effect of Blast Furnace Slag/Fly Ash Ratio on Setting, Strength, and Shrinkage of Alkali-Activated Pastes and Concretes

The aim of this study was to determine the effects of partial fly ash substitution in to a series of alkali-activated concrete based on a high-MgO blast furnace slag BFS. Mixes were activated with ...

Detoxification of municipal solid waste incinerator (MSWI) fly ash by single-mode microwave (MW) irradiation: Addition of urea on the degradation of Dioxin and mechanism.

The detoxification of municipal solid waste incinerator (MSWI) fly ash dioxins urgently requires an effective treatment technology. In this study, we adopted a single-mode microwave (MW)-based pyrolysis to treat MSWI fly ash under N2 atmosphere and further elucidated the main influencing factors, including the chemical inhibitor, for dioxin control. The results show that (1) the detoxification process was optimized with a mass ratio of fly ash to SiC of 1:9, 23.1% (wt%) urea addition and pyrolysis temperature of ˜ 480 °C; (2) the total polychlorinated dibenzo-p-dioxins and dibenzofurans (PCDD/Fs) destruction efficiency and the bioassay-derived 2,3,7,8-TCDD toxic equivalent (Bio-TEQ) removal efficiency reached 98.5% and 97.9%, respectively, accompanied with ˜ 1.3% of the total amount of dioxin being submitted to exhaust gas; (3) the MW-based pyrolysis of urea (133˜300 °C) was favourable for the generation of hot spots as well as the PCDD/F rapid destruction in fly ash. In addition, the leaching toxicity of heavy metals was also partially reduced after MW pyrolysis reactions. To the best of our knowledge, this is the first report adopting a MW-based pyrolysis to eliminate dioxin in MSWI fly ash with the addition of urea, which is a promising alternative to current methods.

Investigation and Comparison of the Enrichment Potential of Turkey (Şenkaya, Erzurum) Coals with Knelson Concentrator

The quality of coals from, Erzurum varies widely. Two coal samples from this area were compared. The first has a composition of 19% ash, 5700 kcal, and 3% sulfur while the other has 49.20% ash, 3000 kcal, and 1.6% sulfur composition. It is understood that the first coal sample is a high-quality coal. Although the ash content of the second coal sample is determined to be high and the calorie value is low, the low sulfur content is advantageous for the environment. This study aimed at increasing the quality of coal samples by carrying out experiments for reducing the ratio of ash and sulfur with Knelson’s enrichment processes. Chemical analysis, sieve analysis experiments, %ash, %moisture, and %calorie values of each fraction are determined from two different C1 and C2 coal samples taken from the Balkaya village belonging to Şenkaya, Erzurum. Then, %ash, %yield, and %sulfur analyzes were carried out on the coal samples using the Knelson gravity separator enrichment method, and the results were evaluated for coal samples.

Loss of ash trees in riparian forests from emerald ash borer infestations has implications for aquatic invertebrate leaf-litter consumers

Rapid loss of ash (Fraxinus spp.) trees in riparian forests from an invasive insect, the emerald ash borer (EAB; Agrilus planipennis Fairmaire, 1888), could pose risk of altering organic matter inputs to water bodies that underpin many aquatic ecosystem processes. We measured the composition of riparian forests and their leaf-litter contributions to headwater streams and determined the relative palatability of ash leaves and leaves of three other common riparian trees to aquatic invertebrate leaf-litter consumers (the stonefly (Pteronarcys sp.) and the cranefly (Tipula sp.)) in laboratory microcosms and whole invertebrate communities in forest streams. Ash trees contributed, on average, 24% to riparian tree density and 20% to total litterfall. Among the four common streamside trees accounting for 65% of total litterfall, ash was the first or second most preferred food source for consumers. Leaf packs without ash decomposed at slower rates than packs containing 25%–100% ash leaves. Preferential feeding on ash leaves infers a high-quality food source selected by consumers, and this concurred with comparatively high N content and low C–N ratio of ash leaves. Aquatic invertebrate communities on leaf packs in streams differed among leaf mixtures with or without ash, although community dissimilarity was low. The loss of ash in riparian forests represents an EAB-induced reduction in a high-quality resource subsidy to organic matter consumers in streams. We discuss how this has implications for risk predictions and management response strategies.

Concrete sulfate corrosion coupled with hydraulic pressure

A type of sealed steel box was designed to simulate sulfate attack and hydraulic pressure on concrete. Cup-shaped concrete specimens with water/cement (w/c) ratios of 0.4, 0.5, and 0.6 were fabricated. During the 270 days corrosion time, corrosion behavior on concrete surfaces was observed every 30 days. The extent of damage on concrete was calculated on the basis of the results of periodic ultrasonic testing. After the completion of experiments, X-ray fluorescence analysis was conducted on the element contents at different depth locations of partial specimens. Experimental results showed that hydraulic pressure accelerated the sulfate attack on concrete, and high pressure yielded serious damage. In comparison with zero pressure, the accelerating coefficients of 0.1, 0.2, and 0.3 MPa hydraulic pressures were 1.48, 1.75, and 2.35, respectively. Hydraulic sulfate corrosion can bring additional sulfate ions into concrete and cause chemical and physical sulfate corrosions on concrete simultaneously, thereby resulting in serious damage on concrete. The reduction of w/c ratio and incorporation of fly ash are beneficial for concrete to resist hydraulic sulfate attack.

Comparative Study on Impact of Rice Husk Ash and Fly Ash in Concrete Mix Design for Different Grades of Concrete

This study is about the addition of furnace incinerated Rice Husk Ash into concrete with fly ash. The primary objective of this research work is to investigate the mechanical properties like compressive strength and to reduce the overall cost of construction. RHA and fly ash was used to replace cement partially at different rates, fly ash is used at the rate of 0%, 5% and 10% and RHA at the rate of 5% and 10%. The physical properties of RHA were determined by particle size analyzer. Pozzolanic reactivity of RHA is dependent on silica form. The silica form in RHA is determined by incineration process. To decide it is in crystalline form optimum cement replacement ratio of RHA and fly ash found at 5%+5%. In this investigation firstly two lower grades concrete M-15 and M-20 were prepared and the best result was found with M--15 grade of concrete, then experiment were done with higher grades i.e. M-30 and M-35 grades and there is slight increase in compressive strength in higher grades. CASE-I, for M-15 Grade of concrete during the experiment it has been noticed that the maximum 28 day compressive strength of nominal cube obtained was 21.1 N/mm², for a mix with RHA and fly ash of 5%+5%, 26.7 N/mm² compressive strength is found, and hence an increase in strength over normal concrete is 26.54% when we added RHA. CASE-II, For M-20 Grade of concrete, during the experiment it has been noticed that the maximum 28 day compressive strength of nominal cube obtained was 27.2 N/mm², for a mix with RHA and fly ash of 5%+5%, 34.5N/mm² compressive strength is found, and hence an increase in strength over normal concrete is 26.83% when we added RHA. In case of higher grades in CASE-III, there is 11.33% increase in compressive strength of M-30 grade concrete and in CASE-IV, there is 12.49% increase in compressive strength of M-35 grade concrete. It has been found during experiments that as the percentage of RHA increases the compressive strength increases initially, on further increase in its percentage compressive strength will be reduced.

Method for comprehensive mix design of fly ash geopolymer mortars

This paper presents the development of a new mix design method for fly ash geopolymer mortars activated using combined sodium silicate and sodium hydroxide solutions. For a specified value of compressive strength, specified value of workability, and known chemical properties of the sodium silicate solution to be used in a mixture, the proposed method generates mixture design parameters consisting of activator to fly ash ratio, sodium silicate to sodium hydroxide ratio, and molarity of sodium hydroxide. It was found that the actual compressive strengths and actual workability values obtained from tests were satisfactorily comparable to the designed values. The proposed method concept can be applied to generate relevant mix design charts for various types of geopolymer binders.

Performance Evaluation of Fly Ash-based Geopolymer Concrete Incorporating Nano Slag

<p>This study investigates the effectiveness of fly ash-based geopolymer concrete was conducted to be used as an alternative material to replace the normal concrete. The concrete mixture was prepared by mixing fly ash, fine aggregate, nano-slag, and SP in Na2SiO3/NaOH solution. The mixture was divided into three different groups, with constant water to fly ash ratio of 0.1, and different alkaline content: 0.4, 0.45, and 0.5 of fly ash rather than two curing techniques (moist and autoclave). Several hardeness properties of concrete like compressive strength, density; and splitting tensile strength were examined after 28 d. The microstructural development of geopolymer concrete was monitored using X-Ray Diffractometer. Based on the results of this investigation, it is recommended to cure the geopolymer concrete by autoclaving rather than the traditional moist technique, especially at lower alkaline dosage. However, the partial addition of nano slag by weight of FA had a positive effect on both curing techniques.</p>

Sustainable methodology for production of potassic fertilizer from agro-residues: Case study using empty cotton boll

Potassic fertilizer was synthesized from cotton boll ash retrieved after solar gasification at 1100 °C. The ash was leached through batch-wise multistage countercurrent leaching, while the parameters were optimized using Response Surface Methodology. A face-centered central composite design was employed to scrutinize the effects of four independent variables- number of leaching stages, solvent to ash ratio, leaching time and particle size while the investigated response variable was K+ leaching efficiency, defined as the ratio of extracted K+ to total available water-leachable K+ in the ash. The validated model achieved a desirability of 0.92 and identified the optimal operating leaching conditions with a predicted K+ leaching efficiency of 98.8%. For synthesis of potassic fertilizer, routes of fractional crystallization and selective precipitation (using tartaric acid) were studied; the former recovers 97% of potassium as K2SO4 and KCl whereas the latter recovers 94% as KNO3.

An experimental study on the mix design optimization of fly ash-based geopolymers

Geopolymers are materials suitable for utilization in the construction industry due to their superior properties, such as high strength and good durability. The properties of geopolymers can be configured due to mix design and synthesis conditions. In this study, the mix designs providing the highest compressive strength were investigated. For this purpose the sodium hydroxide/sodium silicate ratios and alkali activator/fly ash ratios were differentiated in the geopolymer synthesis. Fly ash was used as raw material. Geopolymer samples were cured at 80?C for 16 h and aged for 7 and 28 days in laboratory. The highest compressive strength was obtained as 27.36 MPa with alkali activator/fly ash ratio of 0.4 and sodium hydroxide/sodium silicate ratio of 1.0. The degree of reaction values were determined for all the geopolymer samples. Fourier Transform infrared spectroscopy (FTIR) was used for determining the chemical bonds in the structure. The spectrum of the samples revealed that more aluminosilicate gel formed for the sample providing the highest compressive strength.

Physical and Microstructure Properties of Geopolymer Nanocomposite Reinforced with Carbon Nanotubes

The effect of carbon nanotubes on the physical and microstructure properties of fly ash geopolymer has been investigated in this paper. Fly ash was mixed to carbon nanotubes and sing sodium hydroxide (NaOH) at different concentrations of 10 M 15 M and 20 M, respectively. The ratio of sodium hydroxide to sodium silicate (NaOH : Na2SiO3) of (1: 2) and the ratios of fly ash to carbon nanotubes were 1%, 2%, 3%, 4%, and 5% by weight. Then, tested for physical properties such as compressive strength, bulk density, and porosity and all physical properties were improved by increasing the carbon nanotubes contents, and showed superior physical properties over a pure geopolymer matrix. The phase composition and microstructure of geopolymer nano-composites are also investigated using X-ray diffraction (XRD), energy dispersive X-ray spectroscopy (EDS) and scanning electron microscope (SEM) techniques. Results show that the physical properties of geopolymer nano-composites are improved due to addition of carbon nanotubes at curing time of 28 days with concentration of 15 M of sodium hydroxide solution. The optimum 1wt% carbon nanotubes addition exhibited the highest compressive strengths, bulk density and lowers the porosity. The microstructural analysis results indicate that the carbon nanotubes behaves not only as a filler to improve the microstructure, but also as an activator to facilitate the geopolymeric reaction.

Evaluation on the Fluidity and Strength of Recycled Aggregate Concrete with High Quality Fly Ash as Industrial Byproduct

This study aims to improve the mechanical function of recycled aggregate concrete that applied high-quality fly ash, which presents relatively stable quality by maintaining loss ignition below 1% by eliminating combustible carbon and obtained following results. As a result of the test according to the changes in high-quality fly ash ratio, as the ratio of high-quality fly ash increased, the liquidity enhanced. From the results of strength development of recycled aggregate concrete, compressive strength increased with increasing age and, when high quality fly ash is added, the Pozzolan reaction indicates a high strength increase even after 91 days of age. On the other hand, the reason why compressive strength is reduced due to replacement of recycled aggregates is that the properties of the recycled aggregate itself are lower than those of the natural aggregate, and it is judged that destruction occurs first at the surface prior to destruction of aggregates or mortar. Compressive strength according to the replacement rate of high quality fly ash tends to increase almost linearly. If high quality fly ash is used in recycled aggregate concrete, it is deemed that up to 28 days, the filling effect by the addition of high quality fly ash and the strength enhancement by the Pozzolan reaction is also exerted in 91 days.

Assessment of groundwater contamination risk due to fly ash leaching using column study

Fly ash contains various elements such as copper (Cu), cadmium (Cd), cobalt (Co), chromium (Cr), iron (Fe), manganese (Mn), sodium (Na), nickel (Ni), lead (Pb), zinc (Zn) potassium (K), and calcium (Ca) that may contaminate the surrounding environment due to leaching. In the present study, Open Column Percolation Test (OCPT) was used to understand the leaching behaviour of various elements from fly ash. The columns were filled with fly ash and underlying soil layer(s) of different particle size. The initial concentrations of different toxic elements for all combinations of column varied from BDL to 0.04 mg/L for Cu, BDL to 0.01 mg/L for Cd, BDL to 0.33 mg/L for Co, BDL to 0.01 mg/L for Cr, BDL to 1.10 mg/L for Fe, 0.32 to 2.23 mg/L for Mn, 0.06 to 0.71 mg/L for Ni, BDL to 0.17 mg/L for Pb, and 1.76 to 13.1 mg/L for Zn. Similarly, initial concentrations of ions ranged from 0.08 to 105.0 mg/L for Na, 2.0 to 87.80 mg/L for K, and 3.90 to 345.0 mg/L for Ca. The concentrations of most of the elements decreased with decreasing particle size and with increasing depth of the underlying soil layers. The study proposed an approach to find a suitable combination of different soil layers below fly ash with proper ratio of fly ash and soil layers to protect the leaching of elements from fly ash. This study will help to design suitable soil liners for safe disposal or utilization of fly ash.

Bearing Behavior of the Fly Ash Deposits on Expressway

The reinforcement treatment for embankment using the fly ash deposits as the filling material for roadbed was clarified in this paper. Studies have shown that fly ash can be used as the filling material for embankment, but the subgrade bearing capacity from the original fly ash deposits cannot meet the requirements for operating. Fly ash has a good condition to run the dynamic consolidation for meeting the requirements of embankment compaction. The modulus of resilience and the California bearing ratio (CBR) of fly ash is close to that of general filling material for embankment. Fly ash also has the engineering properties of high void ratio and low cohesion. The maximum level of compaction of the fly ash deposits can be 93% and the bear capacity can be about twice over before after the treatment.

Improvement of HZSM-5 catalytic performance by rice husk ash addition for methanol to hydrocarbons process

Abstract The catalytic conversion of methanol to hydrocarbons (MTH) of gasoline has been studied over the modification of HZSM-5 zeolite catalysts, which were prepared by different ratios of rice husk ash (RHA) addition. The catalysts were characterized by BET, XRD, XRF, NH3-TPD, FT-IR and SEM techniques. The dehydration of methanol over prepared catalysts was carried out in a fixed-bed reactor at 300 oC with a constant flow rate of methanol under 1 atm of N2. The liquid hydrocarbons product was analyzed by GC-MS. The analysis showed that the major product provided by RHA-HZSM-5 catalysts was aromatic hydrocarbon-rich. According to the experimental results, the methanol conversion to hydrocarbons has been found to be a function of RHA ratio. The aromatic product selectivity was increased but that of the acidity of catalyst was decreased with the increase of RHA ratio. The study indicated that the hydrocarbon product distribution of the catalysts treated by RHA significantly depended on the acidity of catalyst.