scholarly journals Workability and compressive strength development of self-consolidating concrete incorporating rice husk ash and foundry sand waste – A preliminary experimental study

2019 ◽  
Vol 228 ◽  
pp. 116813 ◽  
Author(s):  
Gritsada Sua-iam ◽  
Natt Makul ◽  
Shanshan Cheng ◽  
Prakasit Sokrai
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Strength Development ◽  
Foundry Sand ◽  
Self Consolidating Concrete ◽  
Compressive Strength Development

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

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
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.

Experimental study on concrete with rice husk ash under sulphuric ACID solutions

2018 ◽  
Vol 7 (4.5) ◽  
pp. 522
Author(s):  
R. Ramya Swetha ◽  
Dr. G.Venkata Ramana ◽  
K. Anusha Hadassa
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Portland Cement ◽  
Sulphuric Acid ◽  
Rice Husk ◽  
Industrial Waste ◽  
Ordinary Portland Cement ◽  
Rice Husk Ash ◽  
Acid Solutions ◽  
Iron And Calcium

This investigation shows the results on aggressive sulphuric acid on the concrete combined with rice husk ash (RH) when partially replaced for ordinary Portland cement. The husk ash, which mainly contains aluminum ion, silica, iron and calcium oxides, is an industrial waste and poses disposal problems. In this study, the effect of various concentrations (1%, 3%, 5%) of sulphuric acid (H2SO4) on Concrete replaced with various percentages (0%,5%,10%,15% and 20% by weight of cement) of RH is evaluated in-terms of residual compressive strength. The loss of compressive strengths of concrete immersed in various H2SO4 solutions for 7 days 28 days and 60 days indicates that at upto 10% replacement increase in strength was observed after which strengths were decreasing. This increase in strength is attributed to pozzolanic activity of RH.  

scholarly journals EXPERIMENTAL STUDY OF CONCRETE PERFORMANCE

2020 ◽  
Vol 2 (1) ◽  
pp. 48-61
Author(s):  
Sang Kee ◽  
Yuhee Park ◽  
Eun Choi
Keyword(s):  
Experimental Study ◽  
Compressive Strength ◽  
Rice Husk ◽  
Rice Husk Ash ◽  
Strength Test ◽  
The Other ◽  
Average Score ◽  
Two Samples ◽  
The Difference ◽  
B Test

This study was experimental in nature and conducted with the view to make comparison between two samples. The first sample consisted of concrete with rice husk ash mixed in it and the other sample was without such addition. The first test conducted to test the performance was simple measurements. The results show that for the sample without addition of rice husk ash, the density was 2355.97 and for included sample, the density was 2354.44 with insignificant differences (t-stat= 0.766, P>.05). For V-B test, the sample without addition of rice husk as was 8.34 and for include sample, it was 8.01. The differences for V-B for both samples were statistically insignificant (t-stat=1.431, P>.05). The slump test without for the sample without addition of rice husk was 12.75 and for included sample, it was 18.56. The difference was statistically significant (t-stat=2.455, P<.05). The compressive strength for excluded sample was 24.32 and for included sample was 20.01. The results were statistically insignificant (t-value= 1.13, P>.05). For flexural strength test, for excluded sample, the average score was 9.02 and for included sample, the average score was 9.19. The difference was statistically insignificant (t-stat=1.45, P>.05). Overall, the results lead to the conclusion that there are insignificant differences of addition of rice husk ash in concrete.

scholarly journals Physicochemical Properties of Hydrated Portland Cement Blended with Rice Husk Ash

2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joseph Mwiti Marangu ◽  
Cyprian Muturia M’thiruaine ◽  
Mark Bediako
Keyword(s):  
Compressive Strength ◽  
Portland Cement ◽  
Rice Husk ◽  
Elevated Temperatures ◽  
Rice Husk Ash ◽  
Blended Cement ◽  
Strength Development ◽  
Carbonation Depth ◽  
Blended Cements ◽  
Carbonation Resistance

In the presence of significant quantities of carbon dioxide (CO2) and elevated temperatures in the atmosphere due to climate change, cement-based materials are susceptible to carbonation. Blended cements are more prone to carbonation attack than Portland cement. There is a need to evaluate the carbonation resistance of blended cements in a carbonation-prone environment. This paper presents experimental findings obtained from an evaluation of carbonation resistance tests on Rice Husk Ash- (RHA-) blended cement. The blended cement was made by intergrinding of Portland Cement (PC) and RHA to make the test cement (PC-RHA). The RHA dosage in the PC-RHA was varied from 0 to 30% by mass of PC. Pozzolanicity, standard consistency, and setting time tests were conducted on PC-RHA. Mortar prisms measuring 160 mm × 40 mm x 40 mm were separately cast at a water/cement ratio ( w / c ) of 0.50 and 0.60 and cured in water for 2, 7, 14, 28, and 90 days. Compressive strength tests were conducted on the mortar prisms at each of the testing ages. The prepared mortars were also subjected to accelerated carbonation tests in two Relative Humidity (RH) curing regimes, one maintained at an RH greater than 90% and the other between 50–60%. Carbonation resistance of the mixtures was evaluated in terms of the changes in carbonation depth using a phenolphthalein test at the age of 7, 14, 28, and 56 days of curing in a continuous flow of CO2. Compressive strength measurements were also taken during each of the carbonation testing ages. For comparison, similar tests were conducted using commercial PC. The results showed that PC-RHA was pozzolanic while PC was nonpozzolanic. Higher water demand and longer setting times were observed in PC-RHA than in PC. Moreover, there was increased strength development in water-cured samples with increased curing duration. Carbonation results indicated that there was a marked increase in carbonation depth with increased dosage of RHA in PC-RHA binders, increased duration of exposure to CO2, and decreased RH (RH between 50–60%). PC-RHA binders exhibited lower carbonation resistance than PC. In conclusion, for mortars at any w / c ratio, carbonation resistance decreased with increase in RHA dosage and increased w / c ratio.

scholarly journals Effect of Rice Husk Ash on the Hydraulic Conductivity and Unconfined Compressive Strength of Compacted Bentonite Enhanced Waste Foundry Sand

2020 ◽  
Vol 5 (1) ◽  
pp. 85-96
Author(s):  
J. Ochepo
Keyword(s):  
Compressive Strength ◽  
Hydraulic Conductivity ◽  
Rice Husk ◽  
Unconfined Compressive Strength ◽  
Rice Husk Ash ◽  
Foundry Sand ◽  
Liner Material ◽  
British Standard ◽  
Compacted Bentonite ◽  
Waste Foundry Sand

A laboratory study of the hydraulic conductivity, (HC), and unconfined compressive strength, (UCS), of compacted bentonite enhanced waste foundry sand (BEWFS) treated with rice husk ash, (RHA) for possible use as liner material is presented. The bentonite enhanced waste foundry sand, BEWFS, was obtained by blending waste foundry sand (WFS) with 12% bentonite by weight of the WFS and mixing the resulting blend thoroughly to obtain a homogenous mix. RHA was added to the BEWFS in increment of 2, 4, 6, 8 and 10% respectively of the dry weight of the BEWFS. The entire blended material was thoroughly mix together to obtain sample with different content of RHA. Index tests, compaction, UCS and HC tests were carried out on the blended materials to determine the effect of RHA on the behaviour of the BEWFS. HC as well as UCS of the materials were study using three compactive efforts of British standard light, (BSLC), West African standard, (WASC) and British standard heavy, (BSHC) compactive efforts respectively. The results obtained show that addition of RHA to BEWFS affected the index properties of the material marginally where the liquid limit increased to 35 from 32 %, plastic limit reduced from 12 to 11% and plasticity index increased from 20 to 25% respectively. The HC of the material was found to increase slightly from 6.28 x 10-08 to 3.90 x 10-08, 2.64 x 10-09 to 2.07 x 10-08 and 8.55 x 10-11 to 1.83 x 10-10 m/s with addition of up to 10 % RHA content and compacted at BSLC, WASC and BSHC respectively. Similarly, the UCS was found to increase to peak values of 177.22, 288.48 and 454.26 kN/m2 at same RHA content and compactive efforts. The implication of this result is that the addition of RHA up to 10% to BEWFS slightly increase the HC but does not compromise it while the strength gain in term of UCS can be said to compensate for the slight lost in HC. It is recommended that BEWFS treated with between 8 to 10% RHA content and compacted at BSHC compactive effort can be applied as liner in engineered waste containment system.

scholarly journals Synergistic effect of RHA and FCW in alkali-aggregate reaction mitigation

2019 ◽  
Vol 19 (2) ◽  
pp. 7-20
Author(s):  
Patrícia Guillante ◽  
Aguida Gomes de Abreu ◽  
Marlova Piva Kulakowski ◽  
Maurício Mancio ◽  
Claudio de Souza Kazmierczak
Keyword(s):  
Compressive Strength ◽  
Synergistic Effect ◽  
Rice Husk Ash ◽  
Strength Development ◽  
Clay Brick ◽  
Small Loss ◽  
Pozzolanic Material ◽  
Alkali Aggregate Reaction ◽  
Different Types ◽  
Compressive Strength Development

Abstract Pozzolans rich in silica, such as Rice Husk Ash (RHA), contribute to compressive strength gain but at the same time might increase alkali-aggregate reaction (AAR) in mortar mixtures. Pozzolans that have aluminates, such as Fired Clay Brick Waste (FCW), can be efficient to mitigate AAR but tend to lead to a slower compressive strength development. The association of different types of pozzolans, however, may result in a synergistic effect, compensating individual deficiencies. This paper presents a study of mixtures containing RHA, FCW and these two materials combined, aiming to obtain benefits in the mechanical behavior and in the durability regarding AAR. A substitution rate of 20% Portland cement by pozzolanic material was used. Through accelerated AAR tests and compressive strength measurements, it was found that while RHA is considered harmful to AAR - even when using an innocuous aggregate - FCW presents benefits, also avoiding this deleterious effect when combined with RHA. The same occurs in the compressive strength development, where RHA compensates a small loss of compressive strength associated with the use of FWC alone.

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