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Chemical Research in Chinese Universities 2021年第3期37卷 757-762页

作者： CHEN Zhixiao QIAN Miaomiao LIU Chang XUE Beichen YULiyun ZHU Yanchao WANG Xiaofeng State Key Laboratory of Inorganic Synthesis&Preparative Chemistry College of ChemistryJilin UniversityChangchun130012P.R.China Jilin Province Product Quality Supervision Test Institute Changchun130103P.R.China

rice husk ash(RHA),obtained by pyrolysis of rice husks,can be used as a potential reinforcing filler for rubber *** this work,ball milling in ethanol(ethanol-assisted milling)was used to hydroxylate the surface of RHA,promoting the graft modification of bis-(γ-triethoxysilylpropyl)-tetrasulfide(Si69).The obtained modified RHA(RHA-EM-Si69)was filled into the natural rubber/butadiene rubber(NR/BR)composites,and the filler-rubber interactions were *** consequence,RHA-EM-Si69 filled NR/BR composites showed overall improvement in the mechanical properties compared with RHA filled NR/BR *** tear strength increased from 13.37 kN/m to 34.71 kN/m,and the tensile strength increased from 1.84 MPa to 7.75 *** black(N774)was also used for comparison under the same *** method provides a potential for promoting the value of RHA in rubber industry.

关键词： Ethanol-assisted milling rice husk ash Rubber reinforcement

Concrete with Highly Active rice husk ash

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Journal of Wuhan University of Technology(Materials Science) 2004年第3期19卷 74-77页

作者：冯庆革 Hachinohe Institute of Technology(Japan)

The overall aim was to investigate the effect of highly active rice husk ash (RHA) produced by an industrial furnace on some properties of concrete. The strength, pore volume and pore distribution of concrete and the Ca(OH)-2 content in concrete were investigated by JIS A 1108 (Method of test for compressive strength of concrete), a mercury instrument porosimeter, and the thermogravimetric analysis, respectively. The results show that,with RHA replacement of cement,the compressive strength of concrete is increased evidently;the average pore radius of concrete is greatly decreased, especially the portion of the pores greater than 20nm in radius is decreased while the amount of smaller pores is increased, and the more the RHA replacement, the less the amount of Ca(OH)-2 in concrete. The latter two results are the main reasons for the strength enhancement of concrete.

关键词： rice husk ash pore structure pozzolanic activity concrete

Experimental evaluation of rice husk ash for applications in geopolymer mortars

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Journal of Bioresources and Bioproducts 2021年第2期6卷 160-167页

作者： G.Ogwang P.W.Olupot H.Kasedde E.Menya H.Storz Y.Kiros Department of Mechanical Engineering College of EngineeringDesignArt and TechnologyMakerere UniversityP.O.Box 7062Kampala-Uganda Department of Biosystems Engineering Gulu UniversityP.O.Box 166GuluUganda Thuenen Institute of Agricultural Technology Bundesallee 4738116 BraunschweigGermany Department of Chemical Engineering KTH Royal Institute of TechnologySE 10044 StockholmSweden

rice husks obtained from upland and lowland rice varieties were characterized for composition and content of *** of the rice husk varieties was fired at temperatures of 600,800 and 900℃ for a soaking period of 3 *** resultant rice husk ash was analyzed for oxide composition and crystallinity using X-ray fluorescence and diffraction techniques,*** generated amorphous ash with the highest silica content,together with metakaolin,aggregate,water,and an alkaline activator was employed to formulate geo-polymer mortar prisms according to the standard EN *** showed that the content of ash in the varieties ranged from 18.3%to 28.6%dry *** of this,89 wt%-96 wt%was silica,with amorphous and crystalline forms of silica obtained at 600℃ and 900℃,respectively,regardless of the rice ***,at 800℃,the silica in the generated ash exhibited both amorphous and crystalline *** amorphous ash generated at 600℃ was used in formulation of geopolymer *** and flexural strength of the formulated mortar after 7 days of curing was 1.5 and 1.3 MPa,*** results reveal the firing protocol to form pozzolanic ash,with potential applications in mortar production.

关键词： rice husk ash Metakaolin Activator Geopolymer mortar Characterization

Study the Hydration and the Microstructure of Cement Blended with rice husk ash in Comparison with Silica Fume

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武汉理工大学学报 2010年第17期32卷 252-255,260页

作者： NGUYEN V T YE G VAN B K BUI D D Faculty of Civil Engineering and Geosciences Delft University of TechnologyP.O. Box 50482600 GADelftThe Netherlands Department of Building Materials Hanoi University of Civil EngineeringHanoi 700803Vietnam

rice husk ask (RHA) is not a ultra-fine material as silica fume (SF),but possesses a very high specific surface area because of its porous structure. With the similar chemical composition of RHA and SF,the activity of RHA,therefore,is different from that of SF. The objective of this work is to study the hydration and the microstructure of Portland cement blended with RHA in comparison with SF. The test results show that SF refined the pore structure of cement paste better than RHA. However,the effect of RHA on cement hydration is more pronouned than that of SF for the mixture with low water to binder ratio.

关键词： hydration isothermal calorimetry mercury intrusion porosimetry (MIP) microstructure rice husk ash silica fume

Hydration process of rice husk ash cement paste and its corrosion resistance of embedded steel bar

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Journal of Central South University 2020年第11期27卷 3464-3476页

作者： WANG Hui ZHANG Ai-lian ZHANG Lin-chun WANG Qian HAN Yan LIU Jun-zhe GAO Xiao-jian SHI Fei-ting LIN Xue-yan FENG Li-yu School of Civil and Environmental Engineering Ningbo UniversityNingbo 315000China School of Civil Engineering Sichuan College of Architectural TechnologyDeyang 618000China School of Construction Engineering Qingdao Agricultural UniversityQingdao 266000China School of Civil Engineering Harbin Institute of TechnologyHarbin 150090China Civil Engineering Department Yancheng Institute of TechnologyYancheng 224051China

Thermogravimetric analysis and electrical resistivity were used to determine the hydration process of cement paste with rice husk ash(RHA)(0−15%)and water-cement ratio of 0.4 in this work.X-ray diffraction(XRD)method and scanning electron microscopy(SEM)were used to survey crystal composition and microstructures of specimens cured for 3 h,1 d,7 d and 28 ***,electrical parameters(electrical resistance and AC impedance spectroscopy)of steel bars reinforced cement paste were investigated to study the effect of RHA on the corrosion *** showed that RHA could affect the cement hydration by hydration promotion and pozzolanic *** evaluation function for electrical resistivity and curing ages fitted well with linear increasing *** addition of RHA higher than 5%demonstrated a decreasing role in the electrical resistivity of cement paste at earlier curing ages(3−7 d).Meanwhile,when at later curing ages(7−28 d)the result was the ***,RHA demonstrated positive effects on corrosion resistance of steel bars in cement paste.

关键词： rice husk ash thermogravimetric analysis electrical parameters X-ray diffraction corrosion resistance

Study on Preparation of rice husk ash with High Specific Surface Area and Its Chemical Reactivity

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Chinese Journal of Chemical Engineering 2004年第5期12卷 711-715页

作者：冯庆革林清宇童张法杉田修一 Department of Environmental and Civil Engineering Hachinohe Institute of Technology 88-1 Myo Hachinohe031-8501 JapanSchool of Chemistry and Chemical Engineering Guangxi University Nanning 530004 China School of Chemistry and Chemical Engineering Guangxi University Nanning 530004 China Department of Environmental and Civil Engineering Hachinohe Institute of Technology 88-1 Myo Hachinohe 031-8501 Japan

Preparation of rice husk ash with high specific surface area and chemical reactivity of the product are reported in this paper. The amorphous rice husk ash with high specific surface area of 311 m2·g-1 was produced by heating acid treated rice husk at 700℃ for 4 h. The isotherms of rice husk ash are similar in shape to type Ⅱof Brunaner's classification with mesopores being predominant. The rice husk ash has a high chemical reactivity,especially that pretreated with acid. This chemical reactivity depends on ashing temperature and pretreatment conditions. There is an exponential relation between the specific surface area of rice husk ash and the change in the conductivity of saturated Ca(OH)2 solution with rice husk ash, from which the specific surface area can be known according to the conductivity change.

关键词： rice husk ash pretreatment specific surface area chemical reactivity

The Influence of rice husk ash on Mechanical Properties of the Mortar and Concrete: A Critical Review

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Open Journal of Civil Engineering 2024年第1期14卷 65-81页

作者： Md Jahangir Alam Mithun Biswas Mohammad Biplab Mia Shahin Alam Md Mosabber Hossain College of Civil and Transportation Engineering Hohai University Nanjing China School of Civil Engineering Chang’an University Xi’an China

Increasing the population and infrastructure in both emerging and developed countries requires a considerable amount of cement, which significantly affects the environment. The primary materials of concrete (‘cement’) production emit a large quantity of CO2 into the environment. Also, the cost of conventional building materials like cement gives motivation to find geopolymer waste materials for concrete. To reduce harmful effects on the environment and cost of traditional concrete substance, alternative waste materials like rice husk ash (RHA), ground granulated blast-furnace (GGBS), fly ash (FA), and metakaolin (MK) can be used due to their pozzolanic behavior. RHA waste material with a high silica concentration obtained from burning rice husks can possibly be used as a supplementary cementitious material (SCM) in the manufacturing of concrete, and its strong pozzolanic properties can contribute to the strength and impermeability of concrete. This review paper highlights a summary of the positive effect of using RHA as a partial substitute for cement in building construction, as well as its optimal inclusion of enhanced mechanical properties like compressive strength, flexural strength, and split tensile strength of mortar and concrete.

关键词： Cement rice husk ash RHA Properties Mechanical Properties Carbon Di-oxide Emission and Greenhouse Gas

Economy of RHA （rice husk ash） in Concrete for Low-Cost Housing Delivery in Nigeria

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Journal of Civil Engineering and Architecture 2013年第11期7卷 1464-1470页

作者： Olonade Kolawole Adisa Department of Civil Engineering Obafemi Awolowo University lle-lfe 220005 Nigeria

Delivery of housing units in adequate quantity and quality has been the pursuits of individuals and successive governments in Nigeria. Still, the gap between demand and supply is becoming wider on daily basis due to exorbitant cost of building materials that is beyond the reach of average Nigerians. Concrete being the most acceptable construction material is expensive due to high cost of cement. Efforts made to reduce the cost of cement were to no avail, thus there is need to look elsewhere. Past researches showed that substituting cement with 15% of RHA （rice husk ash） in concrete improves the performance of concrete and reduces global warming as a result of emissions from cement production. This paper looks into the effect of using RHA as partial substitute of cement on the cost of a low-cost housing unit. Results showed that cement based construction materials are responsible for 82.58% of the total cost in which cement is responsible for 42%. When 15% RHA was used to substitute cement over N90,000 was saved, amounting to about 7% of the total cost of the building. In addition, depletion of natural resources was reduced.

关键词： Housing delivery pozzolan rice husk ash global warming low-cost housing.

Experimental Investigation on the Thermal Properties of Gypsum Plaster-rice husk ash Composite

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Open Journal of Composite Materials 2022年第4期12卷 131-138页

作者： Nuhu Caleb Amulah Abubakar Mohammed El-Jummah Abba Alhaji Hammajam Usman Ibrahim Department of Mechanical Engineering Faculty of Engineering University of Maiduguri Maiduguri Nigeria Department of Mechanical Engineering Faculty of Engineering Nigerian Army University Biu Nigeria Department of Mechanical Engineering Faculty of Engineering Ramat Polytechnic Maiduguri Nigeria

This experimental investigation aims at evaluating the thermal properties of rice husk ash (RHA)—filled gypsum plaster composite for potential applications, as insulating materials. The thermal conductivities of composites of gypsum plaster reinforced with RHA at 0%, 10%, 20%, 30%, and 40% volume fractions were determined experimentally using Lee’s disc method. The experimental results show that integrating RHA reduces the thermal conductivity of gypsum plaster and improves its insulation capacity. The results obtained from the experiments were compared with the Rule of Mixture Model, Maxwell Model, and Russell Model. It was observed that the thermal conductivities obtained from experiments and the theoretical models decreased with an increase in the volume fraction of RHA. The errors associated with the models with respect to experimental results are on the average of 28.7% for Mixture Rule, 31.6% for Russel Model, and 18.8% for the Maxwell Model. An agricultural waste like RHA can be beneficially used for the preparation of composites and, due to improved insulation capability, these composites can be used for applications such as insulation boards and sheathing, hardboard, ceilings of roofs, decorations, etc.

关键词： rice husk ash Thermal Conductivity Gypsum Plaster Lee’s Disc Method Agricultural Waste

Effect of Partial Replacement of Ordinary Portland Cement (OPC) with Ghanaian rice husk ash (RHA) on the Compressive Strength of Concrete

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Open Journal of Civil Engineering 2020年第4期10卷 353-363页

作者： Derrick Nii-Laryea Botchway Russell Owusu Afrifa Charles Yeboah Henaku Civil Engineering Department Takoradi Technical University Takoradi Ghana Civil Engineering Department Kwame Nkrumah University of Science & Technology Kumasi Ghana

The cost of cement has made concrete production expensive such that the housing deficit in developing countries is on the rise despite all the efforts by governments and other stakeholders to produce affordable housing units for the populace. ashes of agricultural products such as rice husk, known as mineral admixtures may have pozzolanic characteristics which would be more beneficial to the housing industry in terms of strength gain and economy than being pollutants to the environment. rice husk ash (RHA), because of its finely divided form and very high silica content and amorphousness, proved to be useful for strength gain of rice husk ash Concrete (RHAC). rice husk ash was manufactured by uncontrolled burning, ground, sieved and replaced with cement at 0%, 5%, 10%, 15%, 20% and 25% in mass for the mixes C20, C25, C30 and C35 where their compressive strengths were verified at 3, 7, 14, 21, 28, 56, 90 and 180 days. The X-ray diffraction pattern list indicated amorphous as well as diffused peak of about 8000 counts of SiO2 representing crystalline structures identified as cristobalite. A physical examination of the RHA showed very fine appearance, grey color and specific gravity of 2.06. The chemical analysis also revealed the existence of oxide content to be 55.8% representing 0.78% of Fe2O3, 54% of SiO2 and 1.06% of Al2O3 representing 20.23% lower than the minimum value of 70% required for pozzolans. Gen

关键词： rice husk ash Agricultural Waste Mineral Admixture Pozzolanic Activity Compressive Strength