scholarly journals Measurement of Pozzolanic Activity Index of Scoria, Pumice, and Rice Husk Ash as Potential Supplementary Cementitious Materials for Portland Cement

2017 ◽  
Vol 2017 ◽  
pp. 1-13 ◽  
Author(s):  
Hieronimi A. Mboya ◽  
Cecil K. King’ondu ◽  
Karoli N. Njau ◽  
Alex L. Mrema

This work investigated the properties of scoria and pumice as supplementary cementitious materials (SCMs) for Portland cement and compared to those of rice husk ash (RHA). X-ray fluorescence, X-ray diffraction, and pozzolanic activity index (PAI) tests confirmed the suitability of these two materials as potential SCMs. Scoria and RHA samples achieved over 75% PAI at 7 days whereas pumice did this after 28 days. Initial and final mean setting times observed for the composite cement blended with these materials were 166 and 285 min, respectively. These setting times are longer than that of ordinary Portland cement but shorter compared to that of common Portland pozzolana cement. The ultimate mean compressive strengths achieved at 28 days of curing were 42.5, 44.8, and 43.0 MPa for scoria, pumice, and RHA, respectively, signifying that these materials are good SCMs. Higher fineness yielded higher ultimate mean strength. For instance, a scoria sample with a fineness of 575 m2/kg achieved the strength of 52.2 MPa after 28 days.

2017 ◽  
Vol 866 ◽  
pp. 187-190
Author(s):  
Thossapon Jaihlong ◽  
Nittaya Jaitanong ◽  
Suparut Narksitipan

In present research, the cement-rice husk ash composites were prepared and characterized. The samples were added fiber optic and rice husk ash was used as replacement cementitious materials at 10, 20, 30 and 40 wt% of portland cement. The samples were demolded after 24 h casting and cured in saturated lime water for 3 days. After these periods, the samples were wrapped with plastics films for 7 and 28 days. Then, samples were dried in air for 24 h. The chemical compositin of portland cement and rice husk ash were characterized by using x-ray fluorence spectrometry (XRF). Additionally, dried samples were analysized phase compositions and crystalline structure by using x-ray diffraction (XRD) technique. The chemical element compositions and microstructure were detected by scanning electron microscopy (SEM), respectively. Moreover, The effect of rice husk ash in these cement composites were investigated in this research.


2012 ◽  
Vol 32 (5) ◽  
pp. 810-821 ◽  
Author(s):  
Débora C. G. de Oliveira ◽  
Michelle S. Rodrigues ◽  
Sérgio F. dos Santos ◽  
Holmer Savastano Junior

The deep bedding is a swine alternative production, especially in the finishing phase, whose byproduct can be recycled, reducing the environmental impact. The objectives of this study were to characterize the ash coming from the controlled burning of the swine deep bedding (SDBA) based on rice husk, and to evaluate their performance in composites as a partial substitute for Portland cement (PC). To measure the differences between SDBA and rice husk ash (RHA) as a reference, we have characterized: particle size distribution, real specific density, x-ray diffraction, electrical conductivity, scanning electron microscopy, chemical analysis and loss on ignition. Samples were prepared for two experimental series: control, and another one with the partial replacement of 30% of SDBA in relation to the mass of the Portland cement. According to the results obtained for physical and mechanical characterization, the composites with SDBA can be used as a constructive element in the rural construction.


Author(s):  
Khalil Ur Rehman ◽  
Afaq Ahmad ◽  
Fawad Ahmad ◽  
Ezaz Ali Khan ◽  
Muhammad Armaghan Siffat

This research study is aimed to evaluate the effects of different calcination temperatures on the properties of rice husk ash such as the chemical and microstructural properties. Rice husk ash is not utilized properly; it is not dumped with proper handling which is also causing environmental issues. Currently researchers are working on supplementary cementitious materials in concrete, in light of which, this research study is aimed to evaluate the effects of burning on Rics Husk Ash (RHA) structure and its pozzolanic reactivity for utilizing it in concrete. The rice husk is burnt at temperatures of 600-800°C for a duration of 8, 16 and 24 hours and for evaluating different chemical and structural properties through tests of X-ray Diffraction (XRD), X-Ray fluorescence (XRF) and Fourier Transform Infrared Spectroscopy (FTIR). It is concluded that burning of rice husk at 600-800°C for duration of 24 hours gives us more reactive and amorphous material and can be used as a cement substitute for sustainable concrete production.


2021 ◽  
Vol 11 (1) ◽  
pp. 23-32
Author(s):  
N. Mesboua ◽  
K. Benyounes ◽  
S. Kennouche ◽  
Y. Ammar ◽  
A. Benmounah ◽  
...  

Abstract The construction industry consumes a large quantity of cement, which therefore leads to a high CO2 emission due to the cement manufacture. The partial replacement of cement by supplementary cementations materials (SCMs) is considered as the most promising alternative to reduce the environmental impact of this industry. This investigation aims to evaluate the performance of calcinated clay (calcined bentonite at 850 °C) used as partial replacement of cement in cement-based mortar. The evaluated performances include the physico-chemical and mechanical properties, as well as microstructural characteristics.. Various characterization tests, including laser granulometry, X-ray diffraction (XRD), and X-ray fluorescence spectrometry (XRF) have been investigated. In addition, the hardened properties of different mortar mixtures were also investigated. Mortar mixtures incorporating different calcinated clay percentages corresponding to 8, 10, 12, and 14%, by mass of total binder content, were proportioned. Termogravimetric analysis (TGA) and its derivative (DTG), Differential scanning calorimetry (DSC), and microstructural (Scanning electron microscopy (SEM)) analysis were carried out on samples of mortar mixtures. Furthermore, the 28-d hardened properties were assessed to assess the pozzolanic activity of the investigated mixtures. Strength activity index (SAI), DSC, and TGA analyzes are presented. The obtained results showed that all the mixtures exhibited adequate pozzolanic activity conforming to the ASTM C618 specifications.


2022 ◽  
Author(s):  
Sunita Kumari ◽  
Dhirendra Singhal ◽  
Rinku Walia ◽  
Ajay Rathee

Abstract The present project proposes to utilize rice husk and maize cob husk ash in the cement to mitigate the adverse impact of cement on environment and to enhance the disposal of waste in a sustainable manner. Ternary concrete / MR concrete was prepared by using rise husk and maize cob ash with cement. For the present project, five concrete mixes MR-0 (Control mix), MR-1 (Rice husk ash 10% and MR-2.5%), MR-2 (Rice husk ash 10% and MR-5%), MR-3 (Rice husk ash 10% and MR-2.5%), MR-4 (Rice husk ash 10% and MR-2.5%) were prepared. M35 concrete mix was designed as per IS 10262:2009 for low slump values 0-25mm. The purpose is to find the optimum replacement level of cement in M35 grade ternary concrete for I – Shaped paver blocks.In order to study the effects of these additions, micro-structural and structural properties test of concretes have been conducted. The crystalline properties of control mix and modified concrete are analyzed by Fourier Transform Infrared Spectroscope (FTIR), Scanning Electron Microscopy (SEM), and X-Ray Diffraction (XRD). The results indicated that 10% Rice husk ash and 5% maize cob ash replaced with cement produce a desirable quality of ternary concrete mix having good compressive strength. The results of SEM analysis indicated that the morphology of both concrete were different, showing porous structure at 7 days age and become unsymmetrical with the addition of ashes. After 28 day age, the control mix contained more quantity of ettringite and became denser than ternary concrete. XRD analysis revealed the presence of portlandite in large quantity in controlled mix concrete while MR concrete had the partially hydrated particle of alite.


2016 ◽  
Vol 869 ◽  
pp. 209-214 ◽  
Author(s):  
Iara Janaína Fernandes ◽  
Daiane Calheiro ◽  
Emanuele Caroline Araújo dos Santos ◽  
Roxane Oliveira ◽  
Tatiana Louise Avila de Campos Rocha ◽  
...  

The use of rice husk ash (RHA) as filler in polymeric materials has been studied in different polymers. Research reported that RHA may successfully replace silica. The silica production process using ore demands high energy input and produces considerable amounts of waste. Therefore, the replacement of silica by RHA may be economically and environmentally advantageous, reducing environmental impact and adding value to a waste material. In this context, this study characterizes and compares RHA of different sources (moving grate and fluidized bed reactor) with commercially available silicas to assess performance as filler in polymeric materials. Samples were characterized by X-ray fluorescence, loss on ignition, X-ray diffraction, grain size, specific surface area, specific weight, and scanning electron microscopy. The results show that RHA may be used as a filler in several polymeric materials.


2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Neeraj Jain

Investigations carried out to study the effect of Cr (VI) (1000–3000 mg/l) on solidification and hydration behavior of Ordinary Portland cement (OPC) and rice husk ash (RHA) blended (10%, 20%, and 30%) cement show that addition of RHA accelerates final setting as compared to control samples (OPC) and retardation in setting time has been observed on increase in rice husk ash concentration (10%–30%). Solidification studies show that the compressive strength of controls and rice husk ash blended samples increases with increase in the curing period and maximum strength was observed with 20% RHA blended samples. With the increase in Cr (VI) concentrations, the strength of OPC and RHA blended samples decreases as compared to controls (without chromium). The results of Toxicity Characteristics Leaching Procedure (TCLP) test, (pH≅3), show that the retention capacity of OPC and RHA blended samples was in the range of 92% to 99% and the leached Cr (VI) concentration was under the allowable limit (5 mg/l) of U.S. EPA. The chemistry of influence of Cr (VI) on hydration of cement was examined by X-ray diffraction which shows the formation of various crystalline phases during solidification in rice hush ash blended cement.


2012 ◽  
Vol 517 ◽  
pp. 430-436
Author(s):  
J.L. Akasaki ◽  
E.J. Silva ◽  
L.C. Sousa ◽  
J.L.P. Melges ◽  
M.M. Tashima ◽  
...  

Rice production in Brazil in 2010 was approximately 12,2 million tons, and to reach that amount several planting techniques were used with different strains of rice in different rice-growing areas. Since Rice Husk Ash (RHA) is the pozzolan of vegetable origin most studied by researchers working in the area of pozzolanic materials, the present paper evaluates the influence that the form of planting, the climate, the soil, the strain of rice and the origin/amount of nitrogen-based fertilizers used in rice cultivation has on the chemical composition and crystallographic properties of RHA. The results obtained in this paper, confirm the importance of carrying out routine chemical analysis and X-Ray diffraction to maintain the quality control of the CCAs produced, because in situations of large-scale production, husks of different origins may be used.


2018 ◽  
Vol 25 (4) ◽  
pp. 15-22
Author(s):  
Abbas Y. Awad ◽  
Mohammed N. Ibrahim ◽  
Mohamed K. Hussein

A336.0 aluminum alloy used to fabricate hybrid composites using rice husk ash (RHA) and MgO particles as reinforcement. The influence of the particles on the wear behavior of A336.0 aluminum alloy as a matrix that reinforced with MgO and RHA was investigated. Firstly, the rice husk burned at 700°C and then heat treated at 1100°C for 2 hrs. The ash characterized by X-ray florescence and X-ray diffraction. Less than 53 and 125 micron are the particle sizes of MgO and RHA respectively. The hybrid composites manufactured using stir casting method in two steps. A336.0 aluminum alloy reinforced with 4:0, 3:1, 2:2, 1:3 and 0:4 of RHA: MgO with 10 wt% total reinforcement phase. Optical microscope and X-ray diffraction were used to characterize the prepared hybrid composites. Dry sliding wear, hardness, apparent density, percentage of porosity and coefficient of friction were examined. Results indicated that porosity, apparent density and hardness enhanced with increasing MgO, while increasing wt% of RHA decreased the apparent density. Results indicated that with inceasing the applied load the wear rate of the composites was enhanced. Coefficient of friction varies inversely with applied load and wt% of RHA. Hardness increased with increasing RHA while the friction coefficient and the wear rate decreased. The minimum wear rates were at 10% RHA and Al-alloy-(RHA-MgO) [3:1] composites, while the minimum friction coefficients were at 10% RHA composites.


2021 ◽  
Vol 22 (4) ◽  
pp. 11-17
Author(s):  
Haider Abbas ◽  
Ammar S. Abbas

In recent years, it has been evident that searching for alternative methods with low-price and eco-friendly features that produce high-quality adsorbents is in high demand. In the present work, Rice husk from Iraqi rice named (Amber) had been used as the primary source to produce rice husk ash (RHA) for the removal of the antibiotic metronidazole (Flagyl) from water. After optimum drying of rice husk, rice husk ash (RHA) was obtained at 600 °C using an electric oven. RHA has been investigated for properties using X-ray diffraction (XRD), porosity, and surface area (SA). The experimental work adsorption data were optimized to evaluate Langmuir and Freundlich constants. The thermodynamic parameters likely a change in Gipp's energy (ΔG), enthalpy (ΔH), and entropy (ΔS). The impacts of increasing temperature on adsorption capacity were investigated, and the results indicate that the pseudo-second-order kinetics model could be presented the dynamic adsorption data that it has. The resultant values for the heat of adsorption and the free energy indicated that adsorption of Flagyl is preferred at low temperatures.


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