Effect of particle size, porous structure and content of rice husk ash on the hydration process and compressive strength evolution of concrete

Denture base is the part of a denture that rests on the foundation tissues and to which teeth areAttached. Denture base may be complete or partial used for the alteration of missing natural teeth.The most popular material utilized for the fabrication of dentures base is the poly (methylmethacrylate) (PMMA) because is distinguished by many characteristic. The remarkable clarity ofa methyl methacrylate resin, its relatively high strength and hardness, its color stability under allconditions of dental use, its insolubility in the mouth fluids, all of these properties combine toprovide an excellent material for the prosthetics denture (S. S Carmen, 2010 and R. K. Alla 2013).This survey illustrate the effect of particle size of powders and weight fraction of natural Bambooand Rice Husk powders on PMMA, with the selected size particles of (25?m and 75?m) andweight fraction (2, 4, 6 and 8wt. %), on compression strength and hardness, and these experiencewere accomplished at a temperature of laboratory. The results showed improved in the hardnessand compression with concentration rate of Rice Husk and Bamboo powders in compositesamples. Also, the highest values of compressive strength and hardness were (300MPa.) and (86)respectively for (PMMA-8%RH) and particle size (25 ?m).

Download Full-text

Effect of Particle Size of Residual Rice-Husk Ash in Consumption of Ca(OH)2

Journal of Materials in Civil Engineering ◽

10.1061/(asce)mt.1943-5533.0001136 ◽

2015 ◽

Vol 27 (6) ◽

pp. 04014178 ◽

Cited By ~ 9

Author(s):

J. H. S. Rêgo ◽

A. A. Nepomuceno ◽

E. P. Figueiredo ◽

N. P. Hasparyk ◽

L. D. Borges

Keyword(s):

Particle Size ◽

Rice Husk ◽

Rice Husk Ash ◽

Effect Of Particle Size

Download Full-text

Desulfurization and Denitrification Performance of Modified Rice Husk Ash-Carbide Slag Absorbent

Materials ◽

10.3390/ma14010068 ◽

2020 ◽

Vol 14 (1) ◽

pp. 68

Author(s):

Yali Wang ◽

Xiaoning Han ◽

Meina Chen ◽

Suping Cui ◽

Xiaoyu Ma ◽

...

Keyword(s):

Functional Groups ◽

Rice Husk ◽

Rice Husk Ash ◽

Research Direction ◽

Cement Industry ◽

Hydration Process ◽

Air Pollution Control ◽

Large Area ◽

Carbide Slag ◽

High Investment

In the cement industry, SO2 and NOx are generally removed separately. There are many problems, such as large area, high investment cost, secondary pollution and so on. Desulfurization and denitrification technology have become a frontier research direction in the field of air pollution control. In this paper, rice husk ash and carbide slag were compounded and modified to prepare modified rice husk ash-carbide slag composite absorbent, and its desulfurization and denitrification performance and mechanism were studied. The results showed that the NO conversion and SO2 conversion of the modified rice husk ash-carbide slag composite absorbent increased by 44% and 2%, respectively, at 700 °C. Fibrous calcium silicate and calcium silicoaluminate hydrates were formed during the hydration process, which made the specific surface area of the absorbent larger and provided more reactive sites. The hydration process increases the content of oxygen-containing functional groups, decreases the hydroxyl/ether C–O functional groups, and increases the content of carboxyl–COO functional groups are conducive to the denitrification reaction.

Download Full-text

Preliminary Study on the Utilization of RHA as a Performance Enhancer for Rubber Mortar

Materials ◽

10.3390/ma14123216 ◽

2021 ◽

Vol 14 (12) ◽

pp. 3216

Author(s):

Jin Li ◽

Peiyuan Chen ◽

Haibing Cai ◽

Ying Xu ◽

Chunchao Li

Keyword(s):

Compressive Strength ◽

Mechanical Strength ◽

Rice Husk ◽

Rice Husk Ash ◽

Capillary Absorption ◽

Optimal Dosage ◽

Positive Effects ◽

Waste Rubber ◽

Chloride Resistance ◽

Preliminary Study

In this study, rice husk ash (RHA) was explored as a strength enhancer for mortars containing waste rubber. The effects of RHA on the flow, mechanical strength, chloride resistance, and capillary absorption of rubber mortar were investigated by substituting up to 20% cement with RHA. The experimental results showed that the incorporation of rubber into mortar could be safely achieved by adding RHA as a cement substitute by up to 20% without compromising the compressive strength of mortar. Moreover, the RHA also exerted positive effects on the enhancement of the chloride resistance as well as the capillary absorption of rubber mortars, for which 15% RHA was found to be the optimal dosage.

Download Full-text

Physical Properties of Cement Mortar Containing Waste Ash

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.804.129 ◽

2015 ◽

Vol 804 ◽

pp. 129-132

Author(s):

Sumrerng Rukzon ◽

Prinya Chindaprasirt

Keyword(s):

Compressive Strength ◽

Fly Ash ◽

Rice Husk ◽

Rice Husk Ash ◽

Cement Mortar ◽

Ash Content ◽

Water Requirement ◽

Test Results ◽

Pozzolanic Material ◽

Materials Used

This research studies the potential for using waste ash from industrial and agricultural by-products as a pozzolanic material. Classified fly ash (FA) and ground rice husk ash (RA) were the materials used. Water requirement, compressive strength and porosity of cement mortar were investigated. Test results indicated that FA and RA (waste ash) have a high potential to be used as a good pozzolanic material. The water requirement of mortar mix decreases with the increases in fly ash content. For ground rice husk ash (RA), the water requirement of mortar mix increases with the increases in rice husk ash content. In addition, the reduction in porosity was associated with the increase in compressive strength.

Download Full-text

Strength and Durability Performance of Alkali-Activated Rice Husk Ash Geopolymer Mortar

The Scientific World JOURNAL ◽

10.1155/2014/209584 ◽

2014 ◽

Vol 2014 ◽

pp. 1-10 ◽

Cited By ~ 20

Author(s):

Yun Yong Kim ◽

Byung-Jae Lee ◽

Velu Saraswathy ◽

Seung-Jun Kwon

Keyword(s):

Compressive Strength ◽

Rice Husk ◽

Rice Husk Ash ◽

Polymerization Reaction ◽

Strength Development ◽

Geopolymer Concrete ◽

Portland Cement Concrete ◽

Mix Proportion ◽

Strength And Durability ◽

Alkali Activated

This paper describes the experimental investigation carried out to develop the geopolymer concrete based on alkali-activated rice husk ash (RHA) by sodium hydroxide with sodium silicate. Effect on method of curing and concentration of NaOH on compressive strength as well as the optimum mix proportion of geopolymer mortar was investigated. It is possible to achieve compressive strengths of 31 N/mm2and 45 N/mm2, respectively for the 10 M alkali-activated geopolymer mortar after 7 and 28 days of casting when cured for 24 hours at 60°C. Results indicated that the increase in curing period and concentration of alkali activator increased the compressive strength. Durability studies were carried out in acid and sulfate media such as H2SO4, HCl, Na2SO4, and MgSO4environments and found that geopolymer concrete showed very less weight loss when compared to steam-cured mortar specimens. In addition, fluorescent optical microscopy and X-ray diffraction (XRD) studies have shown the formation of new peaks and enhanced the polymerization reaction which is responsible for strength development and hence RHA has great potential as a substitute for ordinary Portland cement concrete.

Download Full-text

Mechanical Properties of High Strength Concrete Containing Nano SiO2 Made from Rice Husk Ash in Southern Vietnam

Crystals ◽

10.3390/cryst11080932 ◽

2021 ◽

Vol 11 (8) ◽

pp. 932

Author(s):

Huu-Bang Tran ◽

Van-Bach Le ◽

Vu To-Anh Phan

Keyword(s):

Compressive Strength ◽

Rice Husk ◽

High Strength Concrete ◽

Rice Husk Ash ◽

Chloride Ion ◽

High Strength ◽

Ion Permeability ◽

Strength Concrete ◽

Nano Sio2 ◽

Southern Vietnam

This paper presents the experimental results of the production of Nano-SiO2 (NS) from rice husk ash (RHA) and the engineering properties of High Strength Concrete (HSC) containing various NS contents. Firstly, the mesoporous silica nanoparticles were effectively modulated from RHA using NaOH solution, and subsequently precipitated with HCl solution until the pH value reached 3. The optimum synthesis for the manufacture of SiO2 nanoparticles in the weight ratio of RHA/NaOH was 1:2.4, and the product was calcined at 550 °C for 2 h. The EDX, XRD, SEM, TEM, FT-IR, and BET techniques were used to characterize the NS products. Results revealed that the characteristics of the obtained NS were satisfactory for civil engineering materials. Secondly, the HSC was manufactured with the aforementioned NS contents. NS particles were added to HSC at various replacements of 0, 0.5, 1.0, 1.5, 2.0, and 2.5% by the mass of the binder. The water-to-binder ratio was remained at 0.3 for all mixes. The specimens were cured for 3, 7, 28, 25 days under 25 ± 2 °C and a relative humidity of 95% before testing compressive and flexural strengths. Chloride ion permeability was investigated at 28 and 56 days. Results indicated that the addition of NS dramatically enhanced compressive strength, flexural strength, chloride ion resistance, and reduced chloride ion permeability compared to control concrete. The optimal NS content was found at 1.5%, which yielded the highest strength and lowest chloride ion permeability. Next, the development of flexural and compressive strengths with an age curing of 3–28 days can be analytically described by a logarithmic equation with R2 ≥ 0.74. The ACI code was used, and the compressive strength at t-day was determined based on 28 days with R2 ≥ 0.95. The study is expected to solve the redundancy of waste RHA in southern Vietnam by making RHA a helpful additive when producing high-strength concrete and contributing meaningfully to a sustainable environment.

Download Full-text