Addition Of Rice Husk Ash Research Articles

Study on Physio-Mechanical Properties of Rice Husk Ash Polyester Resin Composite

The rice husk ash/polyester resin composites were prepared by compression molding method and their physical and mechanical properties were studied by universal testing machine. The hardness of the composites were tested by Leeb rebound hardness tester and Vickers hardness tester .The bulk density of the rice husk ash/polyester resin composite decreased with the addition of the rice husk ash, and the water absorption also found to be increased with increase in soaking time. Flexure strength of the composite was decreased randomly with an increase in rice husk ash content. The elastic modulus for the flexure strength increased up to the percentage 0-10% but decreased on 15% and 20% of the rice husk ash/polyester composite. The compressive strength of the composites was decreased randomly with the addition of rice husk ash content, and the elastic modulus for compressive test was increased firstly on the addition of rice husk ash, but it was decreased after 5%. The Hardness of the prepared composite was found to be decreased with an increase of the addition of rice husk ash content due to elastic deformation.

Study on Physio-Mechanical Properties of Rice Husk Ash Polyester Resin Composite

The rice husk ash/polyester resin composites were prepared by compression molding method and their physical and mechanical properties were studied by universal testing machine. The hardness of the composites were tested by Leeb rebound hardness tester and Vickers hardness tester .The bulk density of the rice husk ash/polyester resin composite decreased with the addition of the rice husk ash, and the water absorption also found to be increased with increase in soaking time. Flexure strength of the composite was decreased randomly with an increase in rice husk ash content. The elastic modulus for the flexure strength increased up to the percentage 0-10% but decreased on 15% and 20% of the rice husk ash/polyester composite. The compressive strength of the composites was decreased randomly with the addition of rice husk ash content, and the elastic modulus for compressive test was increased firstly on the addition of rice husk ash, but it was decreased after 5%. The Hardness of the prepared composite was found to be decreased with an increase of the addition of rice husk ash content due to elastic deformation.

폴리프로필렌 섬유 보강 RHA콘크리트의 공학적 특성

Concrete, as a construction material, needs suitable reinforcement for tensile region due to weak tensile strength. Many researches on cement reduction have been attempted for emissions during cement clinker production. In this paper engineering properties of concrete enhanced with polypropylene fiber (PPF) and rice husk ash (RHA) are evaluated. Fiber volume ratios of 0.125~0.375 and RHA replacement ratio of 0~20% are considered for concrete mixture. Lots of test including compressive, split, flexural and the related crack width, impact energy, and pull out test are performed and the results are evaluated considering the fiber ratios, fiber length and RHA replacement. Fiber and RHA ratios have dominant effects on tensile and compressive characteristics respectively, and the concrete with 0.125% of PPF and 10% of RHA shows the most effective enhancement for engineering properties. Appropriate addition of RHA and PPF are very effective both for engineering property enhancement and clean technology.

Evaluation of the mechanical properties and durability of cement mortars containing nanosilica and rice husk ash under chloride ion penetration

In this study, the influence of nanosilica hydrosols and rice husk ash (RHA) on the compressive strength, chloride permeability, electrical resistivity and capillary absorption of single and binary blended mortars was investigated. Results showed that the incorporation of nanosilica improved mortar performance, while RHA did not have a significant influence and mainly attributed to lower strength and durability at early ages. It was found that the addition of RHA in mixes containing nanosilica, dramatically decreased compressive strength at ages of 3 and 7days. However, binary mixtures displayed the best results for strength development and durability at ages of 28 and 90days.

INFLUENCE OF ADDITION OF RICE HUSK ASH ON PORCELAIN COMPOSITION

Rice husk ash (RHA) has long been known to possess high silica content. The abundance of rice husk as agricultural waste makes it the most promising to be used as a supplementary cementations and ceramic material. In this study RHA was used as an additive material on porcelain body. The rice husk was subjected to the chemical pretreatment with 2M HCL, 25 0 C before calcinations to increase silica content of the husk ash. The pressed pellets were sintered at the temperature of 1200 0 C and soaked for 2 hours. It was found that progressive addition of RHA in a porcelain body resulted in early vitrification of the mixture. The compressive strength was the highest at 40wt% addition of RHA. Porosity was the least at 40wt%. It can therefore be concluded that 40wt% addition of RHA into the porcelain body is the best composition. Keywords: RHA, Porcelain, Compressive Strength, Bulk Density, Porosity

A Study on High Performance Fine-Grained Concrete Containing Rice Husk Ash

Rice husk ash (RHA) is classified as a highly reactive pozzolan. It has a very high silica content similar to that of silica fume (SF). Using less-expensive and locally available RHA as a mineral admixture in concrete brings ample benefits to the costs, the technical properties of concrete as well as to the environment. An experimental study of the effect of RHA blending on workability, strength and durability of high performance fine-grained concrete (HPFGC) is presented. The results show that the addition of RHA to HPFGC improved significantly compressive strength, splitting tensile strength and chloride penetration resistance. Interestingly, the ratio of compressive strength to splitting tensile strength of HPFGC was lower than that of ordinary concrete, especially for the concrete made with 20 % RHA. Compressive strength and splitting tensile strength of HPFGC containing RHA was similar and slightly higher, respectively, than for HPFGC containing SF. Chloride penetration resistance of HPFGC containing 10–15 % RHA was comparable with that of HPFGC containing 10 % SF.

Mechanical properties of roller compacted concrete containing rice husk ash with original and recycled asphalt pavement material

This study focused on the effects of rice husk ash (RHA) on the mechanical properties of roller compacted concrete (RCC) designed with original and reclaimed asphalt pavement (RAP) materials. The RCC mixes were produced by partial substitution of cement with RHA at varying amounts of 3% and 5%. Four aggregate combinations including the mix with original aggregate, coarse RAP+fine original aggregate, coarse original aggregate+fine RAP and total RAP were considered. The main experimental design consisted of the compressive strength and three points bending tests. Bending test was used to measure the modulus of rupture, material’s energy absorbency and analyse the fatigue response of RCC mixes. All tests were performed after 7, 28 and 120days curing except the fatigue test that performed on 120days specimens. Adding RHA resulted in higher optimum moisture content (OMC) and lower maximum dry density. Furthermore, adding RAP with different dimensions reduced the OMC and maximum dry density. The material’s flexibility improved upon replacing 3% cement by RHA. However, the energy absorbency reduced by increasing the RHA content to 5%. The fatigue life of RCC mixes containing RAP material was lower than the conventional one. Furthermore, replacing the coarse aggregate by RAP led to higher fatigue life than the fine aggregate. There was a strong relationship (R2>0.90) between the energy absorbency and fatigue response of RCC mixes. At higher stress ratios of 0.72, the mix with higher energy absorbency behaved better under repeated loadings. Besides, a reverse relationship was found between the fatigue life and material porosity. Adding 3% RHA reduced the porosity especially after 120days curing and improved the fatigue resistance. However, the addition of RHA to 5% resulted in higher porosities and lower fatigue lives.

Strength and microstructure analysis of concrete containing rice husk ash under seawater attack by wetting and drying cycles

Concrete containing rice husk ash (RHA), subjected to seawater under wetting and drying cycles, was studied through an investigation of the compressive strength and microstructure of various types of blended cement paste. Five levels of cement replacement (0%, 10%, 20%, 30% and 40% by weight) were studied. The total cementitious content used was 420 kg/m3. A water/binder ratio of 0·49 was used to produce concrete with a target strength of 40 MPa at age 28 days. The performance of blended cement concrete was evaluated based on compressive strength and chloride ion permeability. Microstructural changes in the specimens were determined by differential thermal analysis, X-ray diffraction and scanning electron microscopy. The addition of RHA was found to decrease calcium hydroxide formation by hydration and, consequently, gypsum and ettringite were reduced during seawater attack. RHA at 40% cement replacement improved resistance to seawater attack and effectively decreased ettringite and gypsum formations.

Effects of Rice Husk Ash and Bagasse Ash on Phosphorus Adsorption and Desorption in an Alkaline Soil under Wheat–Rice System

Rice husk ash (RHA) and bagasse ash (BA) are available in large quantities in South Asian countries growing rice and sugarcane. Land application of RHA and BA is likely to influence chemistry of soil phosphorus (P) and thereby P adsorption and desorption. Laboratory studies were carried out to investigate the short-term and long-term effects of RHA and BA application on P adsorption and desorption in an alkaline soil under a wheat–rice system. Addition of RHA or BA (10 Mg ha−1) resulted in a significant decrease in P adsorption compared to the control. The decrease in P adsorption was lower when RHA and BA were applied to either rice or wheat as compared with when applied to both the crops. The BA was more effective in reducing P adsorption than RHA because of its greater P concentration. Fresh addition of RHA and BA at 1% (dry-weight basis) showed a small effect on P adsorption as compared to their long-term application. The Frendulich isotherm equation gave better fit with the experimental data than the Langmuir equation and is reliable to describe the P quantity/intensity relationships of this soil as affected by the additions of RHA and BA. The P-adsorption capacities (revealed from the Langmuir isotherms) of the unamended control, RHA, and BA (applied to both wheat and rice) were 256, 313, and 385 mg kg−1, respectively; the corresponding bonding energies for the three treatments are 0.0085, 0.0041, and 0.0026 L kg−1, respectively. Desorption of P was minimum in the control plots and maximum with BA followed by RHA, especially when applied to both the crops.

The Effect of the Si/Al Ratio on the Properties of Water Treatment Residue (WTR)-Based Geopolymers

This research aimed to develop a cementing material from synthetic geopolymers using water treatment residue (WTR) from a water treatment plant in Bangkaen as an aluminosilicate starting material, with the addition of rice husk ash (BHA) from a paddy factory in Thailand as a source of crystalline silica, to achieve Si/Al ratios of 2.00, 3.00, 4.00 and 5.00. The geopolymers were prepared by NaOH activation of the five compositions of WTR and BHA mixtures, followed by curing at ambient temperature (29±2°C). The compressive strengths of the geopolymers were determined after 3, 7, 28 and 60 days. The samples cured for 28 days were examined by XRD, FTIR and SEM. The Si/ Alratio of 2.00 was found to produce the greatest strength at all curing times. After 7 days, all samples were 30% stronger than the 3 day-samples. XRD revealed the presence of sodium aluminium silicate hydrate, while an FTIR vibration band related to the geopolymer product shifted to 1000 cm-1. SEM revealed a homogeneous non-crytalline and dense microstructure in the sample with the highest Si/Al ratio of 5.00, suggesting that a transformation to sodium silicate had occurred in this sample.

PEMANFAATAN ABU SEKAM PADI SEBAGAI SUBSTITUSI SEBAGIAN SEMEN PADA MORTAR SEMEN PASIR

ABSTRACT Tilization of waste from the combustion of rice husk ash bricks optimally, can solve the problem of environmental pollution. It also can save the construction costs due to reducing in the use of cement. The addition of fine grains that pass the sieve on the size of 0.075 mm can improve the workability of mortar, minimum the voids and finally waterproof ability improve strength. This studi is to determine the performance of rice husk ash on the physical and mechanical properties of mortar. Workability includes the water absorption,ability compressive strength, tensile strength, adhesion of the mortar and optimal percentage value addition of rice husk ash. The research method used in this research was a run by analising a series of samples experiments. The test piece was made with five kinds of mixtures, they were : 1 cement : 5 sand as a comparison and: 1 cement : 5 sand with rice husk ash substitution of cement by 10%, 15%, 20% and 25%, the water factor (cement + rha) between 0.92 to 1.05 and the value spread between 80% - 90% for each test specimen made 25 pieces. Every type of mixture was tested was : the spread, water absorption, compressive strength, tensile strength and bonding strength. The results showed that the addition proportionaly substitution rha composed with addition of water, and inversely composed to the density, the compressive strength, tensile strength, due to a chemical reaction of sio 2 and cao, rice ash husk only serves as a filler since the reaction was take place after 4 days old of sample. Compressive strength of mortar ranged from 10.25 mpa -13.00 mpa, including the type s mortar, for the substitution asp 0%, 10% and 15% asp, and type n for substitution asp 20% and 25% (sni-03-6882 -2002). Bonding strength of mortar was 0.09 mpa (0.9 kg/cm2) at 25% has substitution of asp, while others were not measurable because the specimen were bricks broken, before the bonding between the bricks was loose. Keywords: mortar, rice husk ash, physical and mechanical properties

Radon resistant potential of concrete manufactured using Ordinary Portland Cement blended with rice husk ash

The emission of radon from building materials and soil depends upon the radium content, porosity, moisture content and radon diffusion length of materials. Several techniques have been used to reduce the radon emission from the soil using different flooring materials. But the effectiveness of radon shielding depends upon the diffusion of radon through these materials. The present study proposes a method for producing a radon resistant material for decreasing radon diffusion through it. The method involves rice husk ash (RHA) in addition to cement for the preparation of concrete used for flooring and walls. The radon diffusion, exhalation and mechanical property of concrete prepared by rice husk ash blended cement were studied. The addition of RHA caused the reduction in radon diffusion coefficient, exhalation rates, porosity and enhanced the compressive strength of concrete. The bulk radon diffusion coefficient of cementitious concrete was reduced upto 69% by addition of rice husk ash as compare to that of control concrete.

Experimental Investigations of Performance Characteristics of Rice Husk Ash–Blended Concrete

AbstractThe cement industry is the major contributor of CO2 emission, which could be curtailed by the use of supplementary cementitious materials. Rice husk ash (RHA), one of the supplementary cementitious materials, exhibits high pozzolanic characteristics when properly produced under controlled conditions. In this paper, four concrete mixtures were considered to identify the effect of RHA (produced under controlled conditions) on performance characteristics of the concrete. RHA was added as partial replacement of ordinary portland cement from 10 to 30%. The properties investigated include compressive strength, chloride permeability, water absorption, and sorptivity of RHA-blended concrete. Based on the results, it was found that RHA addition up to 20% in partial replacement of ordinary portland cement lead to increased compressive strength of concrete compared with that of reference mixtures. However, the durability of RHA concrete was on the higher side for all doses compared with the reference mixture...

Mixture Proportioning Of Self Compacting Concrete (SCC) Containing Fly Ash, Rice Husk Ash and Blast Furnace Slag

Self-compacting concrete is a new generation of high-performance concrete with the aim of building durable concrete structures without any skilled laborers for concrete placement. This paper displays mixture proportion of self-compacting concrete and briefly discusses the effects of addition of rice husk ash (RHA), fly ash (FA) and ground granulated blast furnace slag (GGBS) to fresh properties, compressive strength and durability performance of self- compacting concrete.

Polyurethane foams based on modified tung oil and reinforced with rice husk ash I: Synthesis and physical chemical characterization

A chemically modified tung oil was used as the main polyol component in the formulation of viscoelastic (low resilience) polyurethane foams. Rice Husk Ash (RHA), a residue from the rice process industry, was chosen to be incorporated as rigid filler in these materials because of its high silica content. Water was used as blowing agent in order to increase the green nature of the reinforced foams. Physico-chemical and thermal properties of the neat and reinforced foams were measured and analyzed. RHA addition leads to noticeable changes in several properties, mainly thermal conductivity, density and foam morphology, even at the low filler content used in this work. Although the thermal stability was almost unaffected by ash content, a stabilizing effect of the inorganic filler was identified, since the residual char was higher than predicted from theoretical calculations.

Land application of rice husk ash, bagasse ash and coal fly ash: Effects on crop productivity and nutrient uptake in rice–wheat system on an alkaline loamy sand

Large quantities of rice husk ash (RHA), bagasse ash (BA) and coal fly ash (FA) are available in many Asian countries as waste materials, which create a serious disposal problem. Recycling of these ashes on agricultural land can help to improve physical and chemical fertility of soil. The present field experiment was conducted for three and half years to explore the possibilities to utilize these waste materials as soil amendments to improve productivity of rice–wheat system (RWS). The treatments consisted of application of RHA and BA at 10Mgha−1 to either wheat or to rice or to both wheat and rice and 20Mgha−1 to rice alone. The rates used for FA were 15 and 30Mgha−1. Addition of RHA and BA significantly increased the grain yield of wheat and rice but FA caused small increases in crop yields. Direct application of RHA and BA to wheat was significantly superior than their application to rice in the RWS. Direct application of RHA and BA to wheat resulted in 25 and 24% increase in mean grain yield of wheat and 10 and 11% increase in subsequent rice crop, respectively. However, direct application to rice resulted in 8 and 11% yield increase in rice and 10 and 14% increase in subsequent wheat for RHA and BA, respectively. Application of RHA and BA at 20Mgha−1 to rice resulted in lower RWS productivity than that applied at 10Mgha−1 to wheat. There was no significant effect of these ashes on heavy metal contents in grain and straw of the 7th crop of wheat. Application of three types of ashes generally resulted in positive P balance in RWS, however, K balance remained negative. These results suggest that RHA and BA can be recycled successfully in rice–wheat system to improve its productivity with no adverse effect on soil health.

Manufacture and performance of cold bonded lightweight aggregate using alkaline activators for high performance concrete

Cold bonded lightweight aggregate (LWA) was produced by adding 12–50% ground granulated blast furnace slag (GGBS) and/or rice husk ash (RHA) to fly ash (FA) by the pelletization process without cement additives. Alkaline activator solution (as a combination of sodium silicate and sodium hydroxide) was the wetting agent acting as coagulant. The selected LWA was used as coarse aggregate for producing high performance concrete. The addition of GGBS and RHA in both binary and ternary blends improved crushing strength of LWA. The crushing strength of the binary and ternary blends was in the range of 6.0–15.7MPa, while that of the only use of FA was 5.7MPa. The unit weight of LWA ranged from 769 to 1060kg/m3. Fresh high performance lightweight concrete (HPLWC) with unit weight in the range of 1836–2056kg/m3 showed excellent flow-ability without bleeding or segregation. The 28-day compressive strength of HPLWC in the 14.8–38.1MPa range was obtained. The electrical resistivity and ultrasonic pulse velocity results showed that the physical conditions of HPLWC with the binary use of FA and GGBS and the only use of FA was better than that of the others.

Characteristics of Masonry Blocks Manufactured with Rice Husk Ash (RHA) and Lime

Rice husk is one of major agro-waste material in Sri Lanka. Rice Husk Ash (RHA) is produced by burning Rice husk as fuel in brick kiln. Rice husk ash produced by burning at high temperature contains pozzolanic constituents. In Sri Lanka, cement is extensively used to manufacture masonry blocks, although the cost of cement is high. Because of having highly pozzolanic constituents in RHA, it can be used as a building material, instead of cement, to produce cement sand masonry blocks. It was frequently reported that compressive strength of RHA based blocks increases with increasing the RHA content up to 5% and further addition of RHA causes to decrease in compressive strength. In this study, an attempt is made to increase the utilization of RHA by adding Ca2+ to the mixture. Solid masonry blocks, having the size of 360 mm x 100 mm x 170 mm, were cast with the mix proportion of 1:6 Cement - Sand. Blocks were manufactured in two series. In the first series, RHA was used as addition with respect to weight of cement. In this series, four different RHA contents (i.e., 0%, 5%, 10%, and 15%) were used with constant lime content (10%). In the second series, RHA was used as partial replacement for cement with four different RHA contents (i.e., 5%, 10%, 15% and 20%) with constant lime content (10%).The blocks were tested for 7, 14 and 28 Day compressive strength. With the presence of lime (10%), the optimum 28 Day compressive strength was found at the level of 10 % RHA. When RHA was used as addition, the optimum 28 Day average compressive strength of block was found as 4.937 N/mm2. When RHA was used as partial replacement for cement, 28 Day average compressive strength of block was found as 3.467 N/mm2. Thermal performances of the RHA lime based blocks were also investigated. It was found that thermal conductivity of RHA lime based block was lower compared with that of the conventional block. The RHA lime based blocks showed better structural and thermal performances. Increased use of RHA will reduce the unit cost of masonry block while improving sustainability.

Compressive strength and durability properties of Rice Husk Ash concrete

The paper presents the experimental investigation conducted on Rice Husk Ash (RHA) concrete to evaluate the compressive strength and to study its durability properties. In the preparation of rice husk concrete, cement was replaced at various percentage levels such as 5%, 10%, 15% and 20%. Besides control concrete was also prepared for comparison purpose. Two grades of concrete, namely M30 and M60, were prepared. The strength of the concrete increased with the levels of percentage of replacement of 10% at which the increase in strength was 7.07% at 90 days compared to normal concrete. In the case of M60 grade concrete the compressive strength increases with the addition of super plasticizer. In general, Saturated Water Absorption (SWA) increased in the case of RHA Concrete up to 10% replacement level, but the same diminished with addition of super plasticizer. The porosity of RHA Concrete decreased from 4.70% to 3.45% when the replacement level increased from 5% to 20%. There is a further decrease with the addition of super plasticizer. The chloride ion permeability value of RHA Concrete was very low between 100–1000 coulomles, as compared to normal concrete. It was observed from tests that RHA concrete was more resistant to HCl solution than that of control concrete. The percentage of resistance against alkaline attack of M30 grade RHA concrete varied from 25 to 67 and the corresponding value for M60 grade was from 35 to 70 for replacement levels varying from 5% to 20%. Addition of 20% RHA showed higher resistance against sulphate attack for both continuous soaking and cyclic conditions. On the whole addition of RHA as CRM improves the strength and durability properties of concrete to considerable extent.

Effect of nonpozzolanic and pozzolanic mineral admixtures on the hydration behavior of ordinary Portland cement

The effects of nonpozzolanic (marble dust) and pozzolanic (rice husk ash) mineral admixtures on the hydration behavior and mechanical properties of ordinary Portland cement (OPC) have been investigated. The blending of both marble dust (20–60%) and rice husk ash (10–30%) in OPC accelerate the setting as compared to control (OPC). Marble dust addition decreases the strength of OPC and the maximum strength of 54.5 MPa has been achieved on 28 days of curing with 20% of marble dust (CM20). Addition of rice husk ash increases the strength and maximum strength of 65.9 MPa has been observed with 20% of RHA (CR20) blended cement. The formation of various crystalline phases and their effects on hydration behavior of mineral admixtures blended cement were examined by X-ray diffraction (XRD). The changes in microstructure of the hydrated samples were also studied using scanning electron microscope (SEM).