Rice Husk Ash Content Research Articles

Recycling rice husk ash as a filler on biodegradable cassava starch-based foams.

Starch-based foams can be used in packaging development to replace nonbiodegradable petrochemical plastics. However, starch-based materials possess poor mechanical properties and low water resistance. These properties can be improved by adding plasticizers and fillers to the bulk composition. In the present work, the effect of rice husk ash content on physical, morphological, and mechanical properties of cassava starch-based foams produced by thermal expansion was investigated. The composites were formed by mixing cassava starch, rice husk ash (content varying from 0 to 60%), water, and glycerol. The obtained dough was placed in a metallic mold and then expanded in a thermohydraulic press machine. The addition of 20-50% of ash content improved thermal stability, density, and biodegradation of starch-based foams and decreased water absorption capacity. Filled starch-based foams also exhibited smallerpores in internal structure. Compared to foams without ash filler, the addition of 20-40% ash increased the flexural tensile strength and the addition of more than 50% dropped the mechanical resistance. Hence, based on the results obtained, rice husk ash can be a great filler in biodegradable starch-based foams.

Corrigendum to “Optimum rice husk ash content and bacterial concentration in self-compacting concrete” [Constr. Build. Mater., 222 (2019) 796–813

Corrigendum to “Optimum rice husk ash content and bacterial concentration in self-compacting concrete” [Constr. Build. Mater., 222 (2019) 796–813

Performance evaluation of lime–cement–copper slag–rice husk ash composite as a pavement construction material

ABSTRACT This work focuses on the development of new composite materials using industrial wastes such as copper slag (CS) and rice husk ash (RHA), treated with lime (L), and cement (C). For the mixing, the content of CS, RHA, L and C are varied in a range from 51%-100%, 20%-100%, 4%-14% and 4%-10%, respectively. To study the performance of the composite materials, various tests, such as the California bearing ratio (CBR), permeability, and durability tests, were carried out. To study the microstructure characteristics of the developed composite materials, FE-SEM analysis tests were performed. The results indicated that the CBR value decreases with the increase in the binder contents (L and/or C) and RHA contents for both unsoaked and soaked conditions for all the mixes (M3–M14). Out of all the mixes (M3–M14), the highest CBR is obtained for the mix M11, having both L and C. For the unsoaked condition, this value is 21.13% and for the soaked condition, this value is 38.66%, 57.99%, and 65.90% for curing periods of 4, 7, and 28 days, respectively. The CoP of composite materials decreased with an increase in the contents of binding materials (L and/or C) and RHA with the period of curing (7, 14, and 28 days) for all 12 mixes (M3–M14). Out of all the 12 mixes (M3–M14), the highest value of CoP is obtained for mix M3 and the lowest values of CoP are obtained for mix M14, which are 3.22 × 10−4 and 6.58 × 10−5 cm/s, respectively, at 28 days of curing period. According to IRC standards, the results of the durability tests are adequate.

Pengaruh Penggunaan Limbah Abu Sekam Padi dan Viscocrete 1003 Terhadap Kuat Tekan dan Kuat Lentur Beton

The purpose of this study was to determine the effect of the use of waste rice husk ash and viscocrete 1003 on the compressive strength and flexural strength of concrete with variations in the mixture of rice husk ash waste 0%, 25%, 30% and viscocrete 1003 0.6%. The results showed that the chemical content of rice husk ash that had been burned was high SiO2 (Silicon Dioxide), which was 75.5 ─ 87.9 % by weight, while the chemical content of unburned rice husk ash was SiO2 (Silicon Dioxide). Which is high that is equal to 86.9 ─ 94.7% by weight. The compressive strength test value of each variation of the specimen which is converted into 28 days of age is for variation 0% the average compressive strength value is 21.590 MPa, for variation 25% with an average compressive strength value of 15.635 MPa and 30% variation with the average compressive strength value is 11.486 MPa. So it can be concluded that the average compressive strength value from the 0% variation to the 25% variation has decreased by 0.05955%, while from the 25% variation to the 30% variation it has decreased by 0.0415%. The flexural strength test value in terms of the maximum average moment on the slab for each variation of the test object converted into 28 days of age is for 0% variation of 146.820 kN.m, for 25% variation of 165.760 Kn.m and variation of 30% of 170.490 Kn.m. So it can be concluded that the average flexural strength value from the 0% variation to the 25% variation has increased by 3.13%, while from the 25% variation to the 30% variation it has increased by 3.36%.

Optimum utilization of recycled aggregate and rice husk ash stabilized base material

• The unconfined compressive strength and splitting strength of the mixture increased with adding recycled aggregate. • The flexural tensile strength decreased with the increase of RHA content. • After adding recycled aggregate, the dry shrinkage of the mixture was improved. • It is suggested that the content of RHA should not be higher than 40%. With the development of the economy and society, a huge amount of construction and biomass waste are produced every year. Improper disposal of waste will cause pollution to air, soil and groundwater. The sustainable recycling of construction and biomass waste has important benefits for environmental protection. In this paper, the influence of different rice husk ash (RHA) content on the road performance of cement stabilized base material with recycled aggregate was studied in terms of strength, frost resistance and shrinkage. The proportion of RHA replacing cement is 0%, 20%, 40%, 60%, 80% of cement quality, and construction waste recycled aggregate was used to replace 40% of natural aggregate. The main conclusions are as follows: the unconfined compressive strength and splitting strength with recycled aggregate decrease with the increase of RHA content, the compression resilience modulus and flexural tensile strength of the mixture increased obviously, but the frost resistance deteriorated. The dry shrinkage coefficient and temperature shrinkage coefficient of the mixture containing recycled aggregate increased linearly with the increase of RHA content. For the mixture mixed with recycled aggregate, it is recommended that the RHA content should not exceed 40%.

Mechanical and microstructural properties of high-performance concrete made with rice husk ash internally cured with superabsorbent polymers

An experimental study was carried out to determine the properties of rice husk ash (RHA) and its effect on high-performance concrete's (HPC) mechanical and microstructural properties. RHA content was placed at 0–30% at 5% step intervals and a constant water-binder ratio (W/B) of 0.3. A slump flow test was carried out to measure the workability property of the fresh HPC. In contrast, the influence of RHA contents on compressive, splitting tensile, flexural strengths and microstructural properties were examined for the hardened HPC specimens. The X-ray fluorescence (XRF), scanning electron microscopy-energy dispersive x-ray (SEM-EDX), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy-Attenuate total reflectance (FTIR-ATR), Thermogravimetry analysis (TGA), Brunauer, Emmett and Teller (BET) specific surface area and laser diffraction particle size distribution (PSD) were used to access the feasibility of RHA in HPC. XRD and SEM/EDX techniques were conducted to investigate the hydration products and microstructure in hardened HPCs. The post-test examination showed increased compressive, splitting tensile and flexural strengths of HPC samples for a 10% RHA content mix, recording the highest compressive strength in all curing ages. As the curing ages increase, the microstructure of the samples with RHA becomes denser than the control due to the refinement of the microstructure by the RHA incorporated. The XRD and SEM/EDX confirmed the lower calcium hydroxides from pozzolanic reactivity and later formation of C–S–H. The results suggest that RHA can be used as a cement replacement for up to 10% in HPC to produce sustainable concrete.

Synthesis of Zeolite as a Textile Dye Waste Adsorbent from Rice Husk Ash Using Microwave Heating Method

The zeolite was synthesized from rice husk ash with high silica content using the microwave heating method. In the pre-treatment step, the silica content of rice husk ash was extracted by HCl at various concentrations. Zeolite was synthesized by the reaction of rice husk ash, the aqueous solution of NaOH and Al2O3 in the flask reactor, and was treated by microwave heating at various power from 100-200 W. The crystalline phase and the characteristic structure of the product were analyzed by XRD and SEM analysis. Moreover, the surface area of the product was analyzed by BET analysis. The result shows that with 2 M HCl as an acid treatment in the pre-treatment step, the high surface area of the zeolite was obtained, i.e., 266.7 m2/g. The adsorption efficiency of the product was analyzed using methylene blue, methyl orange, and methyl red as the textile dye waste. The result shows that the adsorption efficiency of the product on the methylene blue, methyl orange, and methyl red was 94.2%, 93.89%, and 94.7%, respectively.

Mechanical, water resistance and environmental benefits of magnesium oxychloride cement incorporating rice husk ash

Magnesium oxychloride cement (MOC) has received extensive attention as an eco-friendly cement, but its poor water resistance limits its engineering applications. In this study, MOC mixture (MOCM) was modified with 10–50 % rice husk ash (RHA) (wt% of MgO), and the development of their fresh properties, mechanical strength and microstructure was investigated. The results show that the incorporation of RHA to MOCM increases the setting time of the mixture and reduces its flowability. Due to the fine particle size and high reactivity of RHA, the incorporation of an appropriate amount of RHA to MOCM improves the matrix compactness, thereby enhancing the compressive strength of the samples. Although the microstructure of MOCM deteriorates and the strength decreases after immersion in water, the strength retention coefficient of MOCM with 50 % RHA increases by 24.57 % compared with that of plain MOCM. The incorporation of RHA not only reduces the relative content of magnesium oxide in MOCM, but also generates Mg-Cl-Si-H gel, which is beneficial to improve the water resistance of MOCM. Meanwhile, with the increase of RHA content, the carbon emission of MOCM also decreases. Compared with other modification methods, RHA-modified MOCM performs better in terms of water resistance, environmental benefits and strength enhancement.

Rice Husk Ash as Pore Former and Reinforcement on the Porosity, Microstructure, and Tensile Strength of Aluminum MMC Fabricated via the Powder Metallurgy Method

The handling of rice husk ash (RHA) has been raising environmental concerns, which led to the consideration of incorporating RHA in aluminum metal matrix composite fabrication. Due to the high silicon dioxide content of RHA, it can assist in enhancing both the properties and functionality of pure aluminum. In this research, the fabrication of aluminum metal matrix composite was carried out by utilizing different compositions of RHA, including weight fractions of 10 wt.%, 15 wt.%, and 20 wt.% via a powder metallurgy approach. The element powders, including aluminum and RHA, and magnesium stearate as a binder, were mixed, compacted, and sintered to attain a composite sample in the form of a pellet. The pellet was then characterized using field emission scanning electron microscopy (FESEM-EDX) to identify the pore structure and size for each RHA composition. The samples were also mechanically tested via Archimedes’ Principle and Brazilian Testing to identify their density, porosity, and tensile strength, respectively. The total porosity of RHA-15 wt.% was found to be the highest at 19.19%, yet with the highest tensile strength at 5.19 MPa due to its low open porosity at 4.65%. In contrast, the total porosity of RHA-20 wt.% was found to be slightly lower at 15.38%, with the highest open porosity at 6.95%, which reduced its tensile strength to 5.10 MPa, therefore indicating that reducing open porosity through controlling the composition of reinforcement tends to enhance the mechanical strength of aluminum metal matrix composites.

"Soil Stabilization Using Rice Husk Ash and Coir Fibre "

Soil stabilization is major problem for construction and experimental purposes. Now a days used practical work greatly explains the suitable characters of the locally available Rice Husk Ash (RHA) to be used in the local construction industry in a way to minimize the amount of waste Released in environment causing issues to nature to the environment causing environmental pollution. The soil stabilization methods used in present are very costly because of costly available stabilizing materials like, cement, lime, etc. The cost of stabilization may be minimized by replacing a good proportion of stabilizing agent using RHA. It will minimize the environmental hazards also. Soil sample taken for the study is clay with high plasticity (CH) that requires stabilization. The soil is stabilized using additives rice husk ash and a small amount of coir fibre. Various results are made that shows changes in Maximum dry density (MDD), Optimum moisture content (OMC). California bearing ratio (CBR) and Unconfined compressive stress (UCS). The results obtained in the present study show that the increase in RHA content increases the OMC but decreases the MDD. Also, the CBR value and UCS of soil are considerably improved with the RHA content. From the observation of maximum improvement in strength, 10% RHA content with 6% coir fibre is recommended as optimum amount for practical purposes.

Effect of Using Rice Husk Ash as Partial Replacement of Cement on Properties of Fresh and Hardened Concrete

Abstract Rice husk disposal has become a great challenge for Pakistan being one of the largest rice producer across the globe. Rice Husk Ash (RHA) contains sufficient pozzolanic properties which opens up opportunities for its usage as cementitious material as partial replacement of Ordinary Portland Cement (OPC). In this research RHA was added as cement replacement in different percentages by weight of cement i.e. 0%, 6%, 12%, 18% and 24% at constant mix ratio of 1:2:4 and water-cement ratio of 0.6 that is M15 grade concrete with a target strength of 15-20 MPa. The properties of concrete like workability, compressive strength, tensile strength, flexure strength, and water permeability were investigated by casting standard concrete samples in the form of cubes, cylinders and beams in addition to cost comparison study The outcomes show that workability of fresh concrete increases with an increase in RHA content and almost all concrete properties studied in this research gave more favorable results at 6% replacement level compared with the control mix.

Performance evaluation of green mortars developed from a ternary eco-cement of industrial solid wastes

The performance of green mortars (GMs) incorporating an eco-cement made from various proportions of rice husk ash (RHA), ground granulated blast-furnace slag (GGBFS) and circulating fluidised bed combustion fly ash (CFA) was evaluated. Different RHA contents (15 wt%, 30 wt% and 45 wt%) were used to replace GGBFS (by weight) and these mixtures were activated by 15 wt%, 20 wt% and 25 wt% CFA by the total weight of GGBFS and RHA. The engineering properties of the mortars were examined by compressive strength, splitting tensile strength, water absorption, porosity and dynamic Young's modulus tests. Sulfate resistance tests and scanning electron microscopy (SEM) were conducted to evaluate the durability and microstructure of the GMs. The test results demonstrated that the content of RHA and CFA strongly impacted the properties of the GMs. The mortars with 20 wt% CFA and <30 wt% RHA showed the best performance at later ages. CFA decreased the sulfate resistance of the GMs, while RHA increased sulfate resistance and significantly reduced thermal conductivity. SEM images of the samples showed amorphous gels and the ettringite crystal-like phase, leading to a dense microstructure of the mortars.

Compressive strength prediction of rice husk ash using multiphysics genetic expression programming

Rice husk ash (RHA) is obtained by burning rice husks. An advanced programming technique known as genetic expression programming (GEP) is used in this research for developing an empirical multiphysics model for predicting the compressive strength of RHA incorporated concrete. A vast database comprising of 250 data points is obtained from the extensive and consistent literature review. Different parameters such as age, RHA content, cement content, water content, amount of superplasticizer and aggregate content are used as inputs. A closed-form equation solution was obtained to predict the compressive strength of RHA based on input parameters. The performance of GEP is evaluated by comparing it with regression models. Statistical parameter R2 is used to assess the results predicted by GEP and regression models. Statistical and parametric analysis is also carried out to determine the influence of inputs on the outcome. The GEP model performed better in all terms as compared to other models.

Rice husk ash and fly ash geopolymer hollow block based on NaOH activated

This research aimed to utilize rice husk ash (RHA) to produce rice husk ash and fly ash (FA) geopolymer hollow block based on NaOH activated. RHA was ground for 15, 30, 60, and 90 min. The RHA to FA ratios of 10:90, 20:80, 30:70, 40:60, and 50:50 by weight and 14 molar sodium hydroxide were used. The compressive strengths of geopolymer paste were tested at 7, 28, and 60 days. The compressive strengths and percentages of water absorption of the geopolymer blocks were tested at 7 and 28 days. The microstructure of block was also characterized using SEM and mapping techniques. The results showed that the increase in RHA content increased the compressive strength of the geopolymer. The RHA contained amorphous silica and increase the SiO2/Al2O3 ratio and strength. The compressive strength of geopolymer increased with the increase in RHA fineness. The mix with 50% RHA content, i.e. 50FA50RH-15 M mix with 28-days compressive strength of 8.5 MPa was chosen to produce rice husk ash and fly ash geopolymer hollow block. The microstructure of rice husk ash and fly ash geopolymer hollow block showed the presence of the geopolymerization reaction products with small amount of unreacted RHA and FA particles. The carbon footprint of rice husk ash and fly ash geopolymer hollow block was around two-third of that of the Portland cement system. The result confirms that the rice husk ash and fly ash geopolymer hollow block could be used with compressive strength and water absorption complied with standard.

CONSOLIDATION CHARACTERISTICS OF LATERITIC SOIL TREATED WITH RICE HUSK ASH

Lateritic soil was treated with 0, 4, 8, 12 and 16% rice husk ash (RHA) by dry weight of soil to determine its consolidation properties. Test carried out include; particle size distribution, specific gravity, compaction test with varying compactive efforts (British Standard Light (BSL), West African Standard (WAS) as well as British Standard Heavy (BSH)) and consolidation test. Samples for consolidation test were compacted and then cured for 7, 28 and 56 days; then subjected to one dimensional consolidation testing to observe the influence of curing period and compactive effort on its consolidation characteristics. Index tests showed improved geotechnical properties. The maximum dry density (MDD) for BSL compaction decreased with a rise in RHA content from 1.72 to 1.42 Mg/m3 while optimum moisture content (OMC) increased from 16.5 to 27.3% with rise in RHA doses from 0 up to 16%. Similar trend was observed for WAS and BSH energies. The Pre-consolidation pressure rise with increment in RHA content and also with increase in both compactive efforts and curing period with few exceptions. At 12% RHA content, the Pre-consolidation pressure increased from 65 to 66.5kN/m2 at 7 days and 56 days respectively. Increase in RHA content caused a decrease in Compression Index (Cc) and Swelling Index (Cs). Compression Index also decreased with increase in both compactive efforts and curing period. There was no observed trend in the Swell Index with curing period. As the compactive efforts increased, the swell index decreased. The RHA reduced the Coefficient of Volume Compressibility (Mv) and the Coefficient of Consolidation (Cc). Curing period and compactive effort have no effect on Mv and Cc. Based on the results obtained, curing period of atleast 28 days using up to 12% RHA compacted at energy level of BSH improved the properties of the treated soil and can be use for geotechnical engineering applications like embankment or rural roads.

Strength Characteristics of Rice Husk and Corn Cob Ash Blended Cement Concrete

The study investigates the mechanical properties of concrete incorporating Rice husk Ash (RHA) and Concorb Ash (CCA) as cementitious binders. Concrete cubes was prepared from a standardized prescribed mix of 1:2:4. The cement component in the reference mix was replaced with combined % weight of rice husk ash and corncob ash. The physical and chemical composition of RHA and CCA were examined as well as the workability and compressive strength properties of varying percentage of RHA and CCA blended cement concrete. Water–cement ratios of 0.6, was adopted for the reference and blended mixes. A total of 75 concrete cubes of different percentages by weight of combination of RHA and CCA to Portland cement in the order of 0%, 10%, 20%, 30%, and 40% were cast. The strength measurements of concrete were performed at the ages of 7, 14, 21, 28 and 56 days. The results revealed that compressive strength increased with increase in curing age but decreased as the RHA and CCA contents increased. The compressive strength of concrete cubes with the combination of RHA and CCA was lower at early stages but improves significantly up to 56 days. The highest compressive strength was 22.94N/mm2 and 26.27N/mm2 at 56 days for 0% and 10% combination of RHA and CCA respectivelyBased on the test results the study concluded that 10% RHA and CCA content is adequate as supplementary cementitious material for blended concrete.

Stabilization of tropical soil using calcium carbide residue and rice husk ash

Many alternative stabilizers have been used in improving soil properties for road applications. However, they were mostly used to complement/partially replace cement or lime. This study seeks to use zero - cement/lime binders in the evaluation of engineering characteristics of soil stabilized with the best binary Calcium Carbide Residue (CCR) and Rice Husk Ash (RHA) treatment possible. The oxide compositions of the soil, CCR, and RHA were determined. The natural soil was subjected to index property tests), compaction, Soaked California Bearing Ratio (SCBR), Unconfined Compressive Strength(UCS), and erodibility. To achieve optimal CCR: RHA ratio, compaction and CBR were used. Atterberg limits, compaction, SCBR, Unconfined Compressive Strength, and erodibility were used to evaluate the engineering performance of the soil stabilized at 2, 4, 6, 8, 10% of the optimum CCR: RHA mix. The RHA is a class N pozzolan while the CCR's CaO of 61% indicates how cementitious the residue is. The soil sample is non-lateritic. CCR: RHA combined ratio of 40:60% offered the best strength and compaction performances. Further, the addition of the optimum CCR: RHA at 2, 4, 6, 8, 10% improved the soil's Plasticity Index (PI). Only 8% addition had a Maximum Dry Density (MDD) of 1770 kg/m3 meeting the AASHTO standard. The addition of CCR: RHA improved the soil's strength properties in terms of UCS and CBR. However, the CBR values generally do not meet the FMWH and AASHTO recommendations for subgrade. Erodibility behaviour showed that increasing CCR and RHA content improves soil durability. CCR and RHA have undoubtedly increased soil strength, but not to the desired level. Therefore, further research should be conducted to determine their compatibility with other stabilizers.

Application of Alternative Filler in Asphalt Mixture: An Overview from Indonesia Perspective

A good quality and proper quantity of filler material is one of the significant factors in producing asphalt mixture. Many studies have been highlighted waste material as an alternative filler to improve asphalt mixture performance. Hence, this paper reviewed the performance of asphalt mixture using rice husk ash (RHA) as filler in terms of the Marshall properties. It shows that 6% RHA by weight of total aggregate was commonly used and depicted better in Marshall properties than the others. This study also found that the RHA can be used to replace up to 100% of the conventional filler. Even though, higher RHA content could significantly reduce the stability yet it still within the acceptable range and could be applied at medium traffic load road. In return, the higher the RHA content the more waste material can be utilized for road construction. Thus, minimized the usage natural source materials.

Effects of controlled burn rice husk ash on geotechnical properties of the soil

Pozzolanic reactions of RHA entirely depends on controlled burning condition. The current study illustrates the effects of controlled burn rice husk ash (RHA) on the geotechnical properties of A-2-4 type soil. The compactibility, bearing capacity, compressive strength, and shear strength were investigated as the important geotechnical properties on soil with 0%, 5%, 10%, and 15% of RHA admixtures. Considering the 7-day moist curing, standard Proctor compaction tests, California Bearing Ratio (CBR) tests, Unconfined Compressive Strength (UCS) tests, Consolidated-Drained (CD) Triaxial Compression tests, and Scanning Electron Microscopy (SEM) tests were conducted on soil-RHA combinations. The test results showed that the optimum moisture content increased, but MDD reduced with the increment of RHA content. Soil with 5% RHA showed the increase of CBR (39.5%), UCS (6.0%), modulus of deformation (56.3%), cohesion (11.8%), and angle of internal friction (6.3%) compared to control specimen which indicated that the application of burnt RHA at a controlled temperature significantly enhanced the geotechnical properties of soil. SEM image on soil with 5% RHA also observed the best microstructural development.

Mitigation of autogenous shrinkage of high-strength concrete using rice husk ashes with distinct pore structures

The effect of particle size (50% passing size (D50) of 20 μm, 14 μm and 7 μm) and content (8%, 10% and 12% by mass) of rice husk ash (RHA) on the autogenous shrinkage evolution of high-strength concrete was investigated. RHA samples were selected based on differences in their pore structures, which were investigated by means of nitrogen adsorption isotherms, scanning electron microscopy and absorbency tests. Cement–pozzolan hydration development was studied using isothermal calorimetry. The concretes were subjected to mercury intrusion porosimetry and compressive strength tests. Considering a statistical 22 factorial analysis with a central point, the results showed that D50 and the interaction between D50 and RHA content influenced the autogenous shrinkage at 28 and 100 days. The water absorbed internally by the preserved RHA pore structure (D50 ≈ 20 μm) in the high cement replacement (12% RHA) mixes reduced the final autogenous shrinkage of concrete without a decrease in compressive strength. In addition, the RHA with a more preserved pore structure accelerated the hydration kinetics by heterogeneous nucleation. However, this behaviour did not influence the early autogenous shrinkage results.