Experimental Study on Quality Control of Moderate-Strength Commercial Concrete

2012 ◽  
Vol 174-177 ◽  
pp. 460-463
Author(s):  
Jing Sun ◽  
Jing Shun Yuan ◽  
Xiao Hong Cong ◽  
Hong Bo Liu

For the quality control of commercial concrete, it is important to choose correct raw- material and mixture ratio. C40 and C50 concrete were prepared in dry and cold climate environment, using local raw materials and a large amount of fly ash. Specific researches were made about different kinds and dosage of superplasticizers on the slump of concrete, slump loss and the intensity of the impact. The results show that naphthalene series superplasticizer JK-2 and 30% of fly ash can ensure that slump of the mixture concrete reach more than 180mm, slump loss is less than 30mm in an hour, strength of hardened paste will not be reduced, and concrete can be prepared with low costs.

Processes ◽  
2020 ◽  
Vol 8 (12) ◽  
pp. 1609
Author(s):  
Goreti Botelho ◽  
Ofélia Anjos ◽  
Letícia M. Estevinho ◽  
Ilda Caldeira

Spirits are alcoholic beverages commonly consumed in European countries. Their raw materials are diverse and include fruits, cereals, honey, sugar cane, or grape pomace. The main aim of this work is to present and discuss the source, quality control, and legal limits of methanol in spirits produced using fruit and honey spirits. The impact of the raw material, alcoholic fermentation, and the distillation process and aging process on the characteristics and quality of the final distilled beverage are discussed. In addition, a critical view of the legal aspects related to the volatile composition of these distillates, the origin and presence of methanol, and the techniques used for quantification are also described. The methanol levels found in the different types of spirits are those expected based on the specific raw materials of each and, almost in all studies, respect the legal limits.


Minerals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 835
Author(s):  
Martin Nguyen ◽  
Radomír Sokolář

This article examines the process for the synthesis of forsterite–spinel (2MgO·SiO2/MgO·Al2O3) refractory ceramics from fly ash and alumina as sources of aluminum oxide. Raw materials were milled, mixed in different ratios and sintered at 1500 °C for 2 h. Sintered samples were characterized by XRD, thermal analyses and SEM. Porosity, water absorption, bulk density, refractoriness, refractoriness under load and thermal shock resistance were also investigated. The impact of fly ash as a raw material was investigated in accordance with the resulting properties and microstructure of samples with fly ash and alumina as the raw materials. Due to the positive effect of flux oxides (iron oxides and alkalis) on sintering, the mullite contained in fly ash completely decomposed into silica and alumina, which, together with magnesium oxide, formed spinel. This led to improved microstructural and mechanical properties and thermal shock resistance. In particular, mixtures with 10 wt.% and 20 wt.% of fly ash had the most promising results compared to alumina mixtures. Both modulus of rupture and thermal shock resistance were improved, while the impact on refractory properties was minimal. The novelty of this research lies in the recycling of fly ash, a by-product from coal-burning power plants, into a raw material for the production of forsterite–spinel refractory ceramics.


2020 ◽  
Vol 10 (1) ◽  
pp. 49
Author(s):  
Suharto Suharto ◽  
Muhammad Amin ◽  
Muhammad Al Muttaqii ◽  
Syafriadi Syafriadi ◽  
Kiki Nurwanti

Experimental study on the use of basalt stone originated from Lampung has been conducted to evaluate its potential for a partial substitute of raw material in production of cement clinker. The basalt stone contains minerals of anorthite, augite, and albite phases that are required for clinker formation. In this study, the main raw materials were 80% limestone, 10% silica sand, 9% clay and 1% iron sand. The raw material in these experiments were mixtures 90% or 80% of the main raw material and 10% or 20% of basalt stone. The effect of adding coal to raw materials was also studied to see the possibility of an increase in clinkerization temperature inside the raw material mixture, and at the same time to see the effect of coal ash on clinker composition. Clinker obtained from heating of raw materials at a temperature of 1100oC had LSF of 94.1% and 95.1% (heating time of 1 and 3 hours). If heating is carried out at 1200oC, the clinker had LSF of 97.7% and 98.0% (heating time of 2 and 3 hours, respectively). Depending on the temperature and duration of heating, the clinker mostly had SM in the range of 2.18-2.40% , and AM in the range of 0,78-1.80%. Characterization using XRD showed that the clinker consisted of larnite and gehlenite phases, and dominated by CaO.Batu basalt Lampung telah diuji potensinya sebagai pengganti sebagian bahan baku utama pembuatan klinker semen. Batu basalt tersebut memiliki mineral-mineral dalam fase anorthite, augite, dan albite yang diperlukan pada pembentukan klinker. Pada penelitian ini, bahan baku utama adalah batu kapur 80%, pasir silika 10%, tanah liat 9% dan pasir besi 1%. Campuran bahan baku klinker adalah 90% atau 80% bahan baku utama dan 10% atau 20% batu basalt. Efek penambahan batubara ke dalam bahan baku klinker juga dipelajari untuk melihat kemungkinan kenaikan temperatur klinkerisasi di dalam campuran bahan baku, dan sekaligus untuk melihat efek abu batubara terhadap komposisi klinker. Klinker hasil pemanasan bahan baku pada temperatur 1100oC memiliki LSF 94,1% dan 95,1% (lama pemanasan 1 dan 3 jam). Jika pemanasan dilakukan pada 1200oC, klinker memilik LSF 97,7% dan 98,00% (lama pemanasan 2 dan 3 jam). Tergantung pada temperatur dan lama pemanasan, klinker hasil percobaan ini umumnya memiliki SM 2,18-2,40%, dan AM antara 0,78-1,80%. Karakterisasi dengan XRD menunjukkan bahwa klinker terdiri dari fase larnite dan gehlenite, dan didominasi CaO.


2020 ◽  
Vol 12 (24) ◽  
pp. 10454
Author(s):  
Katarína Teplická ◽  
Martin Straka

This article summarizes the arguments within the scientific discussion on the issue of using mining machines and their life cycle. The main goal of the article is to investigate the impact of a combination of mobile and stationary mining machines and their optimal distribution in the mining process to increase the efficiency of mining and processing of raw materials. The following methods of research were focused on the use of technical indicators for the valuation efficiency of the mining process: a simulation method was used for the distribution of mining machines, comparison analysis was used for the real and past state of mining machines, and a decision tree was used as managerial instrument for optimal alternatives of mining machines. The research empirically confirms and theoretically proves that optimal distribution of mining machines and machine parks is very important for mining companies. The benefit of this research for the mining company was the new location of the machines and the combination of stationary production lines and mobile equipment. The optimal layout of the machines reduced the number of conveyor belts and improved the transfer of limestone processing to mobile devices, saving time, which was reflected in transport costs. The results can be useful for other mining companies seeking to create an optimal machine park.


2013 ◽  
Vol 641-642 ◽  
pp. 574-577 ◽  
Author(s):  
Ying Tao Li ◽  
Ling Zhou ◽  
Mao Jiang ◽  
Yu Zhang ◽  
Jun Shao

In this paper, the mechanical property experiments of concrete based on the seawater and sea sand have been carried in different raw materials preparation and different conservation environments. The results show that the early strength and late strength of concrete based on seawater and sea sand are better than concrete based on freshwater and sand. There is no significant strength decreased for concrete based on seawater and sea sand under accelerated alternating wet and dry conditions. For concrete based on seawater and sea sand mixed with admixture, the downward trend of late strength is significantly delayed, the late strength of concrete based on the seawater and sea sand mixed with slag gets the most obvious growth trend, while the late strength of seawater and sea sand concrete mixed with fly ash gets the largest increment.


2020 ◽  
Vol 4 (2) ◽  
Author(s):  
Dwi Septiyana Sari ◽  
◽  
Susanti Sundari

Abstract This study discusses the use of fly ash waste from coal burning on the manufacture of PCC (Portland composite cement) at PT. XYZ Lampung. The purpose of this research is to look at the technical studies and the efficiency of raw materials in the use of fly ash in cement making, in this case PCC cement (Portland Composite Cement). The steps taken in analyzing the data in this study were viewed from a technical aspect by means of a physical test, namely the cement compressive strength test at the age of 3 days, 7 days, and 28 days using the Compression Testing Machine. This test was conducted to see the comparison of the compressive strength of PCC cement using limestone and fly ash as raw materials, then calculate the difference in raw material costs in the year before and after the replacement of limestone with fly ash. The results showed that cement with the addition of fly ash after 3 days, 7 days and 28 days had an increased compressive strength value, which increased 21.69%, 16.07% and 8.05% respectively of the compressive strength of cement using limestone. The use of fly ash as a substitute for limestone has an effect on the cost of raw materials, where the difference between the cost of raw materials in 2019 and the cost of raw materials in 2018 is Rp. 39,440,952,074.


Author(s):  
Б.Т. Базарова ◽  
Б.Қ. Копбулсынова ◽  
Ж.А. Аймешева ◽  
B. Bazarova ◽  
B. Kopbulsynova ◽  
...  

Батыс Қазақстан облысындағы кәсіпорындардың эволюциясы экономикалық дамудың жалпы циклдік сипатына байланысты да, әр түрлі сыртқы және ішкі факторлардың осы салаға әсер етуінен, сондай-ақ даму процесінде сөзсіз ауытқулар салдарынан ауытқуларға ұшырайды. Батыс Қазақстан облысының аймақтық агроөнеркәсіптік кешенін тұрақты дамытудың басымдықтары талдау арқылы анықталуы керек. Зерттеудің мақсаты - Батыс Қазақстан облысының агроөнеркәсіптік кешенінің тиімді және тұрақты дамуын зерттеу болып табылады. Бұл тақырыпты зерттеу кезінде статистикалық-экономикалық әдіс, талдау және синтез қолданылды. Ауылшаруашылық кешенінің жеке аймақ ретінде тұрақты дамуы да, жалпы елдің де дамуы ауылшаруашылық кешенінің тұрақты қалыптасуынсыз мүмкін емес, себебі оның түпкі өнімі қайта өңдеу өнеркәсібі болып табылады, ал оның мақсаты - талаптарына сай халықты сапалы өніммен қамтамасыз ету. Талдау көрсеткендей, ауылшаруашылық өндірісінің қазіргі жағдайы, қолайсыз факторлардың әсерінің күшеюімен сипатталады, ең алдымен табиғи факторлардың өндірісінде, жалпы өсімдік шаруашылығы өнімінің жылдық айырмашылықтарын тудырады, және өз кезегінде мал шаруашылығындағы ауытқуларға әкеледі, сонымен қатар оның әсері өңдеуші салаларда сезіледі, ал бұл өнеркәсіптің шикізаты болып табылады. Зертеу барысында 2015 жылдан бастап Батыс Қазақстан облысының аумағында ауыл шаруашылығы өнімдері өндірісінің күрт төмендегені анықталды, бұл жалпы, сондай-ақ өсімдік шаруашылығы мен мал шаруашылығы салалары бойынша да өндіріс тұрақтылығының төмендеуіне әкелді, және ол бүгінгі күнге дейін жалғасуда. Агроөнеркәсіптік кешеннің шикізат саласындағы өндіріс тұрақтылығының төмендеуі қайта өңдеу өнеркәсібі өнімдерін өндіруде ауытқулардың артуына әкеліп соқтырды, бұның нәтижесінде халыққа азық-түлік өнімдерін ұсынуда тұрақсыздық пайда болды. Батыс Қазақстан облысының АӨК-ін оның салаларының өнімділігі мен кірістілігін арттыруға бағытталған одан әрі дамыту өндірісті жаңғыртуды және қайта жарақтандыруды, оның инфрақұрылымын дамытуды және салалық кластерлерді қалыптастыруды талап етеді. Кілт сөздер: агроөнеркәсіп кешені, тербеліс, аграрлық сектор, өндіріс, халық саны, агротехника, экономика, талдау, өнімдер, өсімдік шаруашылығы. The evolution of enterprise in the West Kazakhstan region is subject to fluctuations due to both the general cyclical nature of economic development and the impact of various external and internal factors on this industry, as also fluctuations unavoidable in the evolution process. The priorities for sustainable evolution of the regional agro-industrial complex of the West Kazakhstan region should be identified through analysis. The goal of the research is to study the effective and sustainable development of the agro-industrial complex of the West Kazakhstan region. Through studies this topic, the statistical-economic method, analysis and synthesis were used. Sustainable development of the agro-industrial complex of both a particular region and the country as a whole is impossible without the stable functioning of its core - agriculture, the final product of which is used by the processing industry, whose goal is to provide the population with high-quality products in volumes that meet their requirements. Current state of agricultural production, as the analysis shows, is characterized by an increase in the influence of unfavorable factors on production, first of all natural ones, which cause annual differences in the production of gross crop production, which, in turn, convey fluctuations to the livestock industry and, as a result, affects the processing industries. it is the raw material of the industry. In the course of the study, it was found that, since 2015, in the territory of the West Kazakhstan region, there has been a sharp decline in agricultural production, which led to a decrease in the stability of production in general, and in the fields of crop and livestock production, which continues to the present. A decrease in the sustainability of production in the raw materials sector of the agro-industrial complex entailed an increase in fluctuations in the production of products of the processing industry, which ultimately resulted in the emergence of an instability in the supply of food to the population. Further development of the agro-industrial complex of the West Kazakhstan region, aimed at increasing the productivity and profitability of its industries, requires the modernization and re-equipment of production, the development of its infrastructure and the formation of industry clusters.


2009 ◽  
Vol 92 (4) ◽  
pp. 1016-1020 ◽  
Author(s):  
Sohan S Chitlange ◽  
Prajakta S Kulkarni ◽  
Dada Patil ◽  
Bhushan Patwardhan ◽  
Rabindra K Nanda

Abstract Because Ayurvedic herbal preparations contain a myriad of compounds in complex matrixes, it is difficult to establish quality control standards for raw materials and to standardize finished Ayurvedic drugs. A novel, accurate, and valid fingerprint method was developed using HPLC for quality control of a traditional Ayurvedic Arjuna churna formulation, which is used as a cardiotonic drug. Comprehensive comparison of chromatograms of standardized formulation of Arjuna churna and marketed formulations revealed eight characteristic peaks in chromatograms, which unambiguously confirmed the presence of authentic raw material used in the formulation on the basis of their retention time values and UV data. An HPLC fingerprint was also developed for total sapogenins present in Terminalia arjuna. The six common peaks observed in chromatograms of isolated sapogenins, standardized formulations, and marketed formulations can serve as a quality control tool for qualitative estimation of total saponin glycosides present in an Arjuna churna formulation.


2020 ◽  
Vol 8 ◽  
Author(s):  
Duygu Karabelli ◽  
Steffen Kiemel ◽  
Soumya Singh ◽  
Jan Koller ◽  
Simone Ehrenberger ◽  
...  

The growing number of Electric Vehicles poses a serious challenge at the end-of-life for battery manufacturers and recyclers. Manufacturers need access to strategic or critical materials for the production of a battery system. Recycling of end-of-life electric vehicle batteries may ensure a constant supply of critical materials, thereby closing the material cycle in the context of a circular economy. However, the resource-use per cell and thus its chemistry is constantly changing, due to supply disruption or sharply rising costs of certain raw materials along with higher performance expectations from electric vehicle-batteries. It is vital to further explore the nickel-rich cathodes, as they promise to overcome the resource and cost problems. With this study, we aim to analyze the expected development of dominant cell chemistries of Lithium-Ion Batteries until 2030, followed by an analysis of the raw materials availability. This is accomplished with the help of research studies and additional experts’ survey which defines the scenarios to estimate the battery chemistry evolution and the effect it has on a circular economy. In our results, we will discuss the annual demand for global e-mobility by 2030 and the impact of Nickel-Manganese-Cobalt based cathode chemistries on a sustainable economy. Estimations beyond 2030 are subject to high uncertainty due to the potential market penetration of innovative technologies that are currently under research (e.g. solid-state Lithium-Ion and/or sodium-based batteries).


2018 ◽  
Vol 276 ◽  
pp. 110-115
Author(s):  
Martin Ťažký ◽  
Martin Labaj ◽  
Rudolf Hela

The by-products of energy industry are nowadays often affected by new limits governing the production of harmful gases discharged into the air. These stricter and stricter criteria are often met by electricity producers by changing the combustion process in thermal power plants itself. Nowadays, the SNCR (selective non-catalytic reduction) application is quite common in the combustion process in order to help reduce the nitrogen oxide emission. This article deals with the primary measures of thermal power plants, which in particular consist of a modified treatment of raw materials (coal) entering the combustion process. These primary measures then often cause the formation of fly ash with unsuitable fineness for the use in concrete according to EN 450. The paper presents the comparison of the physico-mechanical parameters of several fly ashes with a different fineness values. The primary task is to assess the impact of non-suitable granulometry in terms of EN 450 on the other physico-mechanical parameters of fly ashes sampled within the same thermal power plant. Several fly ashes produced in the Czech Republic and surrounding countries were evaluated in this way.


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