scholarly journals Partial replacement of cement with rice husk ash in concrete production: an exploratory cost-benefit analysis for low-income communities

2021 ◽  
Vol 13 (3) ◽  
pp. 127-141
Author(s):  
Franco Muleya ◽  
Natasha Muwila ◽  
Chipozya Kosta Tembo ◽  
Alice Lungu

Abstract Cement is an important construction material in concrete production; however, it is expensive and unaffordable for many low-income and rural communities in developing countries. Rice husk is a by-product from the rice mill process, with an approximate ratio of 200 kg rice husk per one tonne of rice produced. This experimental study aimed to investigate the integrity of concrete produced in Zambia using rice husk ash (RHA) to partially replace cement. The primary goal was to carry out a cost–benefit analysis on the use of RHA in concrete. RHA was used to partially replace cement with ratios of 10 %, 20 % and 30 %. The 20 % cement replacement mix produced the optimum 18 MPa concrete strength results at a 0.5 water/binder ratio. This translated in cost reduction of concrete by 12.5 %, which is particularly significant for higher concrete volumes. The produced concrete is suitable for lightly loaded structures, such as foundation footings, surface beds and walkways to benefit low-income communities. The study further concluded that the RHA based concrete was more cost-efficient in structures that were close to areas of rice production due to reduced RHA transportation costs.

2021 ◽  
Vol 15 (1) ◽  
pp. 339-346
Author(s):  
Winfred Mutungi ◽  
Raphael N. Mutuku ◽  
Timothy Nyomboi

Background: Creep in concrete is a long-term deformation under sustained loading. It is influenced by many factors, including constituent materials, environmental conditions, among others. Whenever there is an alteration in the convectional concrete preparation process, the creep characteristics need to be realistically assessed. In the present construction, rice husk ash has been used for partial replacement of cement in concrete production. This is because its properties of both tensile and compressive strength in concrete have been tested and found comparable with plain concrete. However, durability characteristics such as creep, which take place in the long run, have not been realistically assessed. Therefore, it is important to study the creep of rice husk ash concrete, which will further help in the development of a creep prediction model for such concrete for use by design engineers. Objectives: Rice husk ash was used as supplementary cementitious material in concrete, and the creep behavior was studied with the aim of producing a creep prediction model for this concrete. Methods: The cement was replaced with 10% of rice husk ash in concrete with a design strength of 30MPA. Reinforced concrete beams were cast and loaded for flexural creep 35 days after casting. The loading level was 25% of the beam’s strength at the time of loading. The creep observation was done for 60 days. The rice husk used was obtained locally from Mwea irrigation scheme in Kenya. The experiments were carried out in our school laboratory at Jomo Kenyatta university of Agriculture and Technology. Results: The creep strain data of rice husk ash concrete beams was obtained with the highest value of 620 micro strain for 60 days. The results were used to develop a creep prediction model for this concrete. Conclusion: A creep prediction model for rice husk ash concrete has been developed, which can be adopted by engineers for class 30 of concrete containing rice husk ash at a 10% replacement level.


Author(s):  
Savita Chaudhary ◽  
Aditya Pratap Singh

The optimized RHA, by controlled burn or grinding, has been used as a pozzolanic material in cement and concrete. Using it provides several advantages, such as improved strength and durability properties, and environmental benefits related to the disposal of waste materials and to reduced carbon dioxide emissions. Up to now, little research has been done to investigate the use of RHA as supplementary material in cement and concrete production .The main objective of this work is to study the suitability of the rice husk ash as a pozzolanic material for cement replacement in concrete. However it is expected that the use of rice husk ash in concrete improve the strength properties of concrete. Also it is an attempt made to develop the concrete using rice husk ash as a source material for partial replacement of cement, which satisfies the


2011 ◽  
Vol 1 (1) ◽  
Author(s):  
Ramadhansyah Jaya ◽  
Badorul Bakar ◽  
Megat Johari ◽  
Mohd Ibrahim

AbstractThe compressive concrete strength and the gas permeability properties over varying fineness of the rice husk ash were experimentally investigated. The relationships among them were analyzed. In this study eight samples made from the rice husk ashes with a different grain size were used, i.e. coarse original rice husk ash 17.96 μm (RHA0), 10.93 μm (RHA1) 9.74 μm (RHA2), 9.52 μm (RHA3), 9.34 μm (RHA4), 8.70 μm (RHA5), 6.85 μm (RHA6) and 6.65 μm (RHA7). The ordinary Portland cement was partially replaced with the rice husk ash (15 wt%). The test results showed that the RHA3 produced the concrete with good strength and low porosity. Additionally the strength of the concrete was improved due to the partial replacement of RHA3 material in comparison with normal coarse rice husk ash RHA0. On the other hand the influence of OPC and RHA materials on the concrete permeability was affected by the grinding time and age (i.e., curing time). The permeability coefficient decreased with the increasing of curing time. The relationships between compressive strength and permeability coefficient are greatly affected by curing times and are sensitive to the grinding cementitious systems.


2017 ◽  
Vol 13 ◽  
pp. 6140-6150
Author(s):  
A.N. Swaminathen ◽  
S.Robert Ravi

 Concrete is the most extensively used construction material around the world and its properties have been undergoing changes through technological advancements. Varieties of concrete have been developed to enhance the different properties of concrete. An investigation in to the potential use of partial replacement of mineral admixture in high performance concrete (HPC) has carried out. The engineering properties of fresh and hardenedconcrete are obtained by conducting test on slump, vee-bee, compaction factor and compressive strength, flexural strength, spilt tensile strength and modulus of elasticity, in this project partial replacement of cement bymetakaolin and rice husk ash been used for varying replacement of 0+0%, 5+105, 7.5+10%,10+10%,5+12.5%, 10+12.5%, 5+15%, 7.5+15%,  and 10+15%for high strength, workability and also an eco-friendly by less emission of co2. It has been concluded that strength development of concrete blended with metakaolin and rice hush ash was enhanced. It was found that in 7.5% replacement of metakaolin and 12.5% replacement of rice husk ash appear to be the optimum replacement which exhibited more strength. This investigation has proved that the MK and RHA concrete can be used as structural concrete at suitable replacement percentage. 


Author(s):  
Doddipati Srinath ◽  
◽  
Gomasa Ramesh ◽  

Concrete is a commonly used construction material all over the globe. Environmentally conscious construction is essential in today’s society. By using the proper materials, we may achieve long-term construction. RHA is often used as a cementitious product replacement, and in such cases, we may mix RHA with hydrated lime. Many research has been conducted on RHA, and they all indicate that it outperforms other kinds of concrete. The importance of rice husk ash in construction and its applications are the subject of this essay. Many studies have been undertaken to identify appropriate replacements for cement in concrete mixes to reduce our over-reliance on cement as a component in concrete production owing to its contribution to CO2 emissions. This article examined the research on the usage of fly ash and rice husk ash as partial concrete replacements and the chemical composition of these materials, and their impact on concrete compressive strength. The mix was created using a logical approach in which solid components were set, and water and superplasticizer content were modified to get the best viscosity and flowability. Rice husk ash (RHA) is a rice milling byproduct. Its usage as a soil stabilizer provides an environmentally friendly alternative to ultimate disposal. Because RHA is not self-cementitious, a hydraulic binder, such as lime, must be added to create cement types to strengthen the soil. In sandy soils, studies on stabilization using RHA and lime mixtures were carried out. RHA of rice husk incineration in ordinary ovens with no temperature control and laboratory burning at regulated temperatures were utilized. In soil mixes with varying RHA and lime concentrations, cementitious compounds were found to develop. Soils treated with RHA and lime underwent unconfined compression strength testing. All RHA and lime concentrations and periods tested showed strength gains, and all materials created were changed rather than stabilized. The use of RHA to improve sandy soils offers environmental, social, and economic advantages as an alternative to ultimate disposal.


PLoS ONE ◽  
2021 ◽  
Vol 16 (6) ◽  
pp. e0251869
Author(s):  
Frederika Rambu Ngana ◽  
A. A. I. N. Eka Karyawati

The rate of maternal deaths in remote areas in eastern Indonesia–where geographic conditions are difficult and the standard of infrastructure is poor–is high. Long travel times needed to reach emergency obstetric care (EMOC) is one cause of maternal death. District governments in eastern Indonesia need effective planning to improve access to EMOC. The aim of this study was to develop a scenario modelling tool to be used in planning to improve access to EMOC in eastern Indonesia. The scenario model was developed using the geographic information system tool in NetLogo. This model has two inputs: the location of the EMOC facility (PONED) and the travel cost of moving across geographical features in the rainy and dry seasons. We added a cost-benefit analysis to the model: cost is the budget for building the infrastructure; benefit is the number of people who can travel to the EMOC in less than 1 hour if the planned infrastructure is built. We introduced the tool to representative midwives from all districts of Nusa Tenggara Timur province and to staff of Kupang district planning agency. We found that the tool can model accessibility to EMOC based on weather conditions; compare alternative infrastructure planning scenarios based on cost-benefit analysis; enable users to identify and mark poor infrastructure; and model travel across the ocean. Lay people can easily use the tool through interactive scenario modelling: midwives can use it for evidence to support planning proposals to improve access to EMOC in their district; district planning agencies can use it to choose the best plan to improve access to EMOC. Scenario modelling has potential for use in evidence-based planning to improve access to EMOC in low-income and lower-middle-income countries with poor infrastructure, difficult geography conditions, limited budgets and lack of trained personnel.


2018 ◽  
Vol 7 (3.35) ◽  
pp. 68
Author(s):  
Tolmatti Vamshi Krishna ◽  
M. Ashwin Kumar ◽  
Kunchala Anjaneyulu

Bagasse ash (BA), the residue obtained after the burning of sugarcane bagasse as a fuel, has pozzolanic properties with potential use as a supplementary binding material (SCM). Use of Bagasse ash (BA) as a mineral admixture needs to be established, especially in India, where sugarcane cultivation is widespread, to reduce land required for its disposal and cement consumption in construction industry. Hence, to encourage commercial use ofBA with minimum processing, an evaluation of the physical, chemical and  morphological characteristics of a locally available BA and its effect, as SCM on properties of structural concrete was taken up.This research work describes the feasibility of using the Fly Ash (FA) Rice Husk Ash (RHA) and Sugarcane Bagasse Ash(SCBA) waste in concrete production as a partial replacement of cement. This present work deals with the effect on strength and mechanical properties of concrete using Triple blending of cement concrete using FA, RHA and SCBA instead of cement. The cement has been replaced by rice husk ash, accordingly in the range with 0%, 10%, 20% and 30% by weight. Concrete mixture of M20 and M25 and M30, were produced, tested and compared in terms of compressive strengths with the Conventional concrete. These tests were carried out to evaluate the mechanical properties for the test results of7, 14, 28, 56 and 90 days for Compressive strengths and Tensile & Flexural Strengths at 28 days. The durability aspect of the samples for Acid attack, Alkaline attack and Sulphate attack was also tested. The result indicates that the FA, RHA and SCBA improve the Compressive Strength and durability of concrete.  


2017 ◽  
Vol 751 ◽  
pp. 544-549
Author(s):  
Winai Ouypornprasert ◽  
Narong Traitruengtatsana ◽  
Kong Kamollertvara

The objective of this technical paper was to propose the use of optimum partial replacement of cement by pozzolan of high-silica content i.e. nanosilica, silica fume and rice husk ash. Firstly cement hydration, pozzolanic reactions of pozzolan and stoichiometry were reviewed. Then the optimum fractional replacement of cement by pozzolan based on the complete consumption of calcium hydroxide and the strength activity index (SAI) were formulated and proposed. After that the results of a series of tests of cement mortars were shown to verify the proposed concepts. The applicability for the mass concrete production was demonstrated by prediction of mean values of nonnormal distributions from the corresponding specifications.


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