scholarly journals Pengaruh Penambahan Biokar Sekam Padi Terhadap Penyerapan Gas CO2 (Carbon Dioxide) Dan Kuat Tekan Pada Plester Dinding

2019 ◽  
Vol 8 (1) ◽  
pp. 10-22
Author(s):  
Reza Arrafi Rasyid ◽  
Erdawati Erdawati ◽  
Darsef Darwis

Abstrak Pada penelitian ini dilakukan pengolahan limbah sekam padi menjadi biokar sebagai zat aditif dalam mortar yang berperan sebagai absorben gas CO2 di dalam mortar. Tujuan penelitian ini selain untuk memanfaatkan limbah sekam, tetapi juga untuk mengetahui pengaruh penambahan biokar sekam padi terhadap penyerapan gas CO2 dan kuat tekan pada plester dinding. Pada penelitian ini biokar yang digunakan adalah biokar yang dipirolisis pada suhu 500ºC selama 8 jam.  Penambahan biokar dilakukan dengan presentase 0; 10; 12,5 dan 15% dalam campuran mortar dengan komposisi Portland Cement (PC):Pasir (PS) sebesar 1:4 dan faktor air semen sebesar 0,6. Selanjutnya dilakukan pengujian kuat tekan mortar dilakukan setelah perawatan 7 dan 28 hari dan serapan gas CO2. Hasil dari pengukuran kuat tekan dan serpan gas CO2 menunjukan bahwa semakin banyak penambahan presentase biokar dalam campuran mortar akan  menurukan kekuatan plester dinding dan penyerapan gas CO2 pada plester. Kata kunci: Biokar, karbon dioksida, kuat tekan, mortar. Abstract Biochar utilization in various fields of life, where biocar is an additive in mortar that acts as CO2 absorbent in the mortar. This study aims to determine the effect of the addition of biochar rice husk form CO2 absorption and compressive strength on wall plaster. The biochar used was characterized by SEM-EDX and FTIR, while the standard plaster samples, 10% biocar+plaster, and 15% biocar+plaster used SAA. In this study biocar which had been pyrolyzed at 500 °C at a pressure of 10 psi, then added at 0; 10; 12.5 and 15% in mortar mix with the composition of Portland Cement (PC):Sand (PS) was 1:4 and Portland Cement (PC): water (W) of 0.6. Mortar compressive strength testing on 7 and 28 treatment days. From the results of the study, the optimal percentage of biocar addition was 10% with compressive strength of 18.5 MPa and CO2 absorption of 0.14 ppm. More biochar additions to the plaster reduce the strength and absorption of CO2 gasplaster. Keywords: Biochar, carbon dioxide, compressive strength, mortar

2021 ◽  
Author(s):  
Palash Badjatya ◽  
Abdullah Akca ◽  
Daniela Fraga Alvarez ◽  
Baoqi Chang ◽  
Siwei Ma ◽  
...  

This study describes and demonstrates a carbon-negative process for manufacturing cement from widely abundant seawater-derived magnesium (Mg) feedstocks. In contrast to conventional Portland cement, which starts with carbon-containing limestone as the source material, the proposed process uses membrane-free electrolyzers to facilitate the conversion of carbon-free magnesium ions (Mg2+) in seawater into magnesium hydroxide (Mg(OH)2) precursors for the production of Mg-based cement. After a low-temperature carbonation curing step converts Mg(OH)2 into magnesium carbonates through reaction with carbon dioxide (CO2), the resulting Mg-based binders can exhibit compressive strength comparable to that achieved by Portland cement after curing for only two days. Although the proposed “cement-from-seawater” process requires similar energy use per ton of cement as existing processes, its potential to achieve a carbon-negative footprint makes it highly attractive to decarbonize one of the most carbon intensive industries.


2018 ◽  
Vol 7 (4.5) ◽  
pp. 522
Author(s):  
R. Ramya Swetha ◽  
Dr. G.Venkata Ramana ◽  
K. Anusha Hadassa

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.  


2020 ◽  
Vol 2020 ◽  
pp. 1-10
Author(s):  
Joseph Mwiti Marangu ◽  
Cyprian Muturia M’thiruaine ◽  
Mark Bediako

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.


2016 ◽  
Vol 857 ◽  
pp. 311-313
Author(s):  
Ng Hooi Jun ◽  
Mohd Mustafa Al Bakri Abdullah ◽  
Kamarudin Hussin ◽  
Soo Jin Tan ◽  
Mohd Firdaus Omar ◽  
...  

Concrete is produced increasingly worldwide and accounting 10-20% emission of carbon dioxide. The potential long term opposing cost of environmental effects need to recognize. Residue of coal combustion ashes especially bottom ash will use to develop reuse application. This study focused on compressive strength of several composition of bottom ash as cement replacement in mortar. Curing of cement mortar techniques and duration also plays an important role and effects on the strength. The objective of this research is to examine the compressive strength of bottom ash in Portland cement under various compositions and fineness of bottom ash.


Day by day conservatory emissions is increases on earth. In manufacture of Portland cement(PC), obliquely we are escalating the carbon dioxide in atmosphere by the invention of PC.. Industrial by-products such as fly ash(FA), ground granulated blast furnace slag(GGBS), rice husk, bagasse, etc. are mainly used in manufacturing industry because these resources contain good bonding assets, amplified stability and decreased the porosity. evaluate to PC these assets are inexpensively good. Auxiliary by means of these manufacturing by products we are eventually lessening the carbon dioxide. PC with the manufacturing by products such as FA, bagasse , GGBS, Rice Husk Ash, Metakaolin etc., In these materials GGBS, FA, bagasse are commonly used for bursting substitution of PC. match up to PC GGBS, FA, rice husk be as well offer privileged compressive strength results when activate by alkali with similar curing’s. This concrete is known as Geo polymer concrete(GPC). To prepare the GPC we require alkali solutions(AS) like NaOH and Na2SiO3 . arrange the AS, by considering singular molarities of NaOH like 9M and 14M and singular concentrations of Na2SiO3 like 40%. get ready the AS of NaOH and Na2SiO3 discretely one hour before the mixing of GPC. dispose the cubes to find the mechanical properties such as compressive strength, and density of GPC. The specimens were tested after 28 days of special curing’s. To improve the properties of GPC, we are accumulation different fibers and go on it for 28 days of different curing conditions of GPC. finally we know the compressive strengths of different fibers and curing conditions of GPC


2021 ◽  
Author(s):  
Palash Badjatya ◽  
Abdullah Akca ◽  
Daniela Fraga Alvarez ◽  
Baoqi Chang ◽  
Siwei Ma ◽  
...  

This study describes and demonstrates a carbon-negative process for manufacturing cement from widely abundant seawater-derived magnesium (Mg) feedstocks. In contrast to conventional Portland cement, which starts with carbon-containing limestone as the source material, the proposed process uses membrane-free electrolyzers to facilitate the conversion of carbon-free magnesium ions (Mg2+) in seawater into magnesium hydroxide (Mg(OH)2) precursors for the production of Mg-based cement. After a low-temperature carbonation curing step converts Mg(OH)2 into magnesium carbonates through reaction with carbon dioxide (CO2), the resulting Mg-based binders can exhibit compressive strength comparable to that achieved by Portland cement after curing for only two days. Although the proposed “cement-from-seawater” process requires similar energy use per ton of cement as existing processes, its potential to achieve a carbon-negative footprint makes it highly attractive to decarbonize one of the most carbon intensive industries.


2021 ◽  
Vol 2070 (1) ◽  
pp. 012241
Author(s):  
Angitha K Viswanath ◽  
K B Anand

Abstract Climate change is one of the most important environmental problems that our planet Earth is facing. This is due to the increased emission of greenhouse gases such as carbon dioxide. Concrete, the most consumed material in the construction industry is reported to be responsible for about 8% of worldwide carbon dioxide emissions. The manufacturing of ordinary Portland cement is both resource and energy-intensive and is accountable for 1.35 billion tons of carbon dioxide emitted annually. Hence potential alternative to Portland cement widely recognized is the adoption of alkali-activated cement. Alkali-activated cement commonly utilizes industrial by-products such as fly ash, GGBS, etc. along with alkali activators such as sodium silicate and sodium hydroxide. The literature review indicates that the environmental impact due to the usage of Portland cement can be reduced by the adoption of alkali-activated cement. However, the manufacture of alkali activators is likely to contribute to the emission to the environment. In addition, the heat curing commonly adopted during the production of concrete to activate the alkalis might also have a bearing. Hence a comparative study using the lifecycle assessment (LCA) method is carried out to assess the impact due to the production of alkali-activated cement concrete using supplementary cementitious materials (SCM) fly ash and GGBS with varying proportions of alkali activators (sodium silicate and sodium hydroxide). Data is extracted from the published literature corresponding to two different compressive strength ranges of OPC concrete and alkali-activated cement concretes that have utilized four varying proportions of alkali activator ratios. It is then analyzed by the ‘cradle to gate’ approach using LCA software SimaPro. The impact assessment is done using the ReCiPe 2016 method. A comparison of results and their interpretation is done based on its compressive strength ranges, the alkali activator ratios, and the effect due to change in the SCMs utilized.


2021 ◽  
Vol 9 (2) ◽  
pp. 95-99
Author(s):  
ابوالقاسم يحي ابوصبيع ◽  
الطيب حسن اونسة

The compressive strength of concrete is the primary characteristic of concrete quality, as the high durability of concrete is one of the characteristics that gave concrete its position, and low durability is the most important problem facing concrete. This study aims to lay the foundations for forming a preliminary idea on knowing the compressive strength of future concrete other than destroying concrete and following up on it without doing destructive tests for it. In order to obtain results that simulate reality to a great degree. In this research, a laboratory study was conducted where a concrete mixture was made and after conducting experiments on the materials included in the mixture and preparing concrete cubes of ordinary Portland cement and sulfate-resistant cement and compressive strength testing on them in times of 28 days and 60 days and 90 days and 180 days and 365 days and subjected to conditions Treating (water and air) and performing chemical analyzes on it to determine the percentage of chlorides and sulfates in the concrete. From the results of the research, an engineering program was designed using Mat lab program to obtain future strength. And reached by the program to know the compressive strength of future concrete under the influence of the chlorides and sulfate content of concrete and the results were good.  


In this research work, the effect of rice husk ash on concrete produced with cellulose industrial residue was studied. A mix proportion of 1:1.8:3.7 with water cement ratio of 0.47 were used. The percentage replacement of Ordinary Portland Cement (OPC) with cellulose industrial residue and rice husk ash used were 0%, 5%, 10%, 20% 30% and 40%. Concrete cubes of 150mm x 150mm x 150mm of Ordinary Portland Cement/Cellulose Industrial Residue and Ordinary Portland Cement/Cellulose Industrial Residue/Rice Ash were cast and cured at 3,7,28,60 and 90 days respectively. At the end of each hydration period, the concrete cubes were crushed and their compressive strength were determined. The result of compressive strength of 5-40% replacement of cement with cellulose industrial residue ranges from 13.02-32.81 N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the compressive strength of 5-40% replacement of cement with Cellulose Industrial Residue and Rice Husk Ash ranges from 13.17-36.30N/mm2 as against 25.60-42.08N/mm2 for the control test. The result of the initial and final setting time of Ordinary Portland Cement/Cellulose Industrial Residue and Cement/Cellulose Industrial Residue/Rice Husk Ash for 5-40% replacement of cement ranges from 61-118mins, 58-110mins and 620 – 836mins, 598 – 799mins respectively as against 52mins and 590mins for the control test. The main conclusion of this study is that the incorporation rice husk ash into cellulose industrial residue increase the strength of concrete produced. The objective of this study is to assess the strength of concrete produced when two pozzolanic materials were used to replace cement in producing concrete.


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