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Vēsturisko mūrjavu ilgmūžības nodrošināšana Latvijas senatnes būvēs
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/MSAC-2018-0008
Inta Kiriloviča, Margarita Karpe, Inta Vītiņa, Silvija Igaune-Blumberga
{"title":"Vēsturisko mūrjavu ilgmūžības nodrošināšana Latvijas senatnes būvēs","authors":"Inta Kiriloviča, Margarita Karpe, Inta Vītiņa, Silvija Igaune-Blumberga","doi":"10.7250/MSAC-2018-0008","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0008","url":null,"abstract":"Pētījumi par Latvijas kultūrvēsturisko ēku akmens materiālu koroziju kopš 1984. g. tiek veikti Rīgas Tehniskās universitātes Silikātu materiālu institūta Akmens materiālu konservācijas un restaurācijas centrā. Šie pētījumi sniedz bagātīgu materiālu krājumu un pieredzi saistībā ar senatnes būvju ilgmūžības nodrošināšanu. Katra objekta restaurācijas tehnoloģijas izstrādes pamatā ir jābūt rūpīgai izpētei. Līdzšinējā pieredze ir devusi vērtīgas atziņas par mūsdienās pieejamo javu saistvielu (portlandcementa, kaļķu u. c.) izmantošanas nosacījumiem restaurācijas procesos.Ensuring the Permanence of Historical Mortars within Buildings of LatviaSince 1984 research on corrosion of  cultural heritage buildings of Latvia has been conducted in the Centre of Restoration and Conservation of Stone Materials, Institute of Silicate Materials, Riga Technical University. This research provides a wide collection of materials and experience in ensuring the permanence of historical buildings. Accurate investigations must be a fundamental part of the restoration technology of each object. The acquired experience has given valuable knowledge about the aspects of use of different binders (Portland cement, lime etc.) in restoration processes.Keywords – lime, corrosion, mortar, restoration, Roman cement, binder, salts","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"37 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89081977","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Ievads
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/msac-2018-0000
G. Mežinskis
{"title":"Ievads","authors":"G. Mežinskis","doi":"10.7250/msac-2018-0000","DOIUrl":"https://doi.org/10.7250/msac-2018-0000","url":null,"abstract":"Pagājušā gada 1. oktobrī apritēja 70 gadi, kopš dibināta Rīgas Tehniskās universitātes (RTU) Silikātu  tehnoloģijas katedra. Katedras 50 gadu jubilejas reizē RTU izdevniecība publicēja monogrāfiju (brošūru), kurā tika sniegts pārskats par Silikātu materiālu institūtā (SMI) paveikto mācību un zinātniskā darbā no 2002. līdz 2007. gadam.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"22 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90508641","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Augsti poraina oksīdu keramika
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/MSAC-2018-0004
Visvaldis Švinka, Ruta Švinka
{"title":"Augsti poraina oksīdu keramika","authors":"Visvaldis Švinka, Ruta Švinka","doi":"10.7250/MSAC-2018-0004","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0004","url":null,"abstract":"Silikātu materiālu institūtā kopš 2004. g. tiek veikti pētījumi par augsttemperatūras augsti porainu oksīdu keramiku, kas iegūta ar koncentrētas oksīdu pulveru suspensijas liešanas paņēmienu. Poru veidošanās notiek ķīmiskas reakcijas ceļā starp metāliska alumīnija pulveri un ūdeni bāziskā vidē, kur suspensijas pH ir 9,5–10,8. Tādā veidā netiek emitēts CO2, kas parasti notiek, iegūstot keramikas materiālus ar paaugstinātu porainību.Laikā kopš 2007. g. sintezēti materiāli un veikti pētījumi vairākās augsttemperatūras oksīdu sistēmās: cirkonija oksīdu saturošā (promocijas darbs, G. Buļa, Cirkonija oksīdu saturoša augsttemperatūras putu keramika, 2008. g.), korunda- mullīta sistēmā (promocijas darbs, L. Mahņicka-Goremikina, Sintēzes apstākļu un leģējošu piedevu ietekme uz porainas augsttemperatūras oksīdu keramikas īpašībām un struktūru, 2015. g.), alumīnija oksīda sistēmā ar dažādām piedevām (promocijas darbs, I. Zaķe-Tiļuga. Mullītu veidojošu piedevu ietekme uz porainas alumīnija oksīda keramikas īpašībām, 2015. g.; nepabeigts promocijas darbs A. Butlers, Karstumizturīga filtrējoša keramika; maģistra darbs, J. Bobrovika, Augsti poraina siltumizolējoša kordierīta keramika). Pētītie materiāli paredzēti, lai izmantotu tos kā siltumizolējošus materiālus dažādām augsttemperatūras siltuma ierīcēm un arī karstumizturīgiem filtriem.Highly Porous Oxide CeramicsInvestigations of highly porous high temperature ceramic produced by slip casting from concentrated suspensions of raw materials were carried out in the Institute of Silicate Materials since 2004. Pores form due to chemical reaction of metallic aluminium powder with water in basic medium with pH 9.5–10.8. Using this method emission of carbon oxide that usually accompanies fabrication of porous ceramics is avoided. The following investigations in high temperature oxide systems have been carried out since 2007:zirconia containing materials – promotion work by Gerda Bula “Zircon oxide containing high temperature foam ceramic”, 2008;corundum–mullite materials – promotion work by Ludmila Mahnicka- Goremikina “Influence of synthesis conditions and additives on the structure and properties of porous high temperature ceramics”, 2015;alumina materials with various additives – promotion work by Ieva Zake-Tiluga “The effect of mullite-forming additives on the properties of porous alumina ceramics”, 2015;titania containing corundum–mullite materials;cordierite ceramic materials.The goals of these investigations were to obtain of high temperature insulating materials and ceramic filters for filtration of hot and aggressive liquids. Properties of ceramics, such as dependence of thermal conductivity on the temperature and thermal shock durability, were determined.Keywords: aluminium oxide, zirconium oxide, titanium oxide, kaolin, talcum, cordierite, nanopowders, thermal insulation, thermal shock resistance.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"58 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81170980","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Pašattīroši audumi: kas tie ir un kāpēc tādi nepieciešami?
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/msac-2018-0011
Raivis Eglītis, G. Mežinskis, Ieva Buiķe
{"title":"Pašattīroši audumi: kas tie ir un kāpēc tādi nepieciešami?","authors":"Raivis Eglītis, G. Mežinskis, Ieva Buiķe","doi":"10.7250/msac-2018-0011","DOIUrl":"https://doi.org/10.7250/msac-2018-0011","url":null,"abstract":"Pašattīroši audumi ir tekstilmateriāli, kuriem piemīt  spēja  ārēju vides faktoru iedarbībā atbrīvot savu virsmu no dažādiem piesārņojumiem. Šādi audumi ļauj samazināt ūdens un enerģijas patēriņu, kas saistīts ar drēbju mazgāšanu, samazināt infekciju risku, pateicoties to biocīdām īpašībām, kā arī pasargā cilvēkus no UV starojuma. Papildus tam šādus audumus arī būtu grūtāk saslapināt; tas mūsdienu mitrajā klimatā samazinātu diskomfortu no salijušām drēbēm. Šādus efektus pašattīroši audumi iegūtu ar tādiem mehānismiem kā fotokatalīze un superhidrofobitāte. Lai audumi iegūtu augstāk minētās īpašības, piemērotākie ir ZnO un TiO2 nanodaļiņu veidotie pārklājumi. Savukārt pārklājumu ieguvei jāizmanto sola-gēla metode, kas sniedz iespēju izveidot homogēnus pārklājumus pie temperatūrām, kuras iztur organiskas dabas materiāli. Kopš 2011. gada ar šādu audumu izstrādi ir nodarbojies Rīgas Tehniskās universitātes Dizaina tehnoloģiju institūts. Kopš 2016. gada ar šādiem pārklājumiem nodarbojas arī Rīgas Tehniskās universitātes Silikātu materiālu institūtā. Izmantojot savas gadu desmitu laikā iegūtās zināšanas sola-gēla tehnoloģijā un nanostrukturētu pārklājumu ieguvē, sekmīgi uzsākti pētījumi rūpnieciski izmantojamu tehnoloģiju izstrādei kokvilnas audumiem.Self-Cleaning Fabrics: What Are They and How Are They Used?Self-cleaning fabrics are textile materials, which under the influence of various external environmental factors have the ability to rid their surface from various contaminants. Such fabrics make it possible to reduce water and energy consumption associated with washing clothes, to reduce the risk of infections due to their biocidal properties, and to protect people from UV radiation. In addition, such fabrics would also be more difficult to wet. This would reduce the possibility of wet clothes in damp climates. Such effects by self-cleaning fabrics could be achieved through mechanisms of photocatalysis and superhydrophobicity. To develop textiles with above mentioned properties, the most suitable approach is the deposition of coatings formed by ZnO and TiO2 nanoparticles. In turn, the sol-gel method should be used to obtain coatings. This would make it possible to create homogeneous coatings at temperatures that organic materials can withstand. Institute of Design Technologies, Riga Technical University, has been working on the development of such fabrics since 2011. The research in the field of such coatings at the Institute of Silicate Materials, Riga Technical University, has been performed since 2016. Thanks to decades long research in sol-gel technology and nanostructured coatings, the development of commercially available technologies for cotton fabrics has been successfully launched at the Institute of Silicate Materials.Keywords: self-cleaning fabrics, sol-gel method, TiO2, ZnO","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"118 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"77165094","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Minerālo izejvielu pielietošanas un stikla šķiedras defektu izpēte
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/msac-2018-0007
Janīna Sētiņa, G. Mežinskis, V. Akišins, Laila Pētersone, Inna Juhņeviča, Līga Grase
{"title":"Minerālo izejvielu pielietošanas un stikla šķiedras defektu izpēte","authors":"Janīna Sētiņa, G. Mežinskis, V. Akišins, Laila Pētersone, Inna Juhņeviča, Līga Grase","doi":"10.7250/msac-2018-0007","DOIUrl":"https://doi.org/10.7250/msac-2018-0007","url":null,"abstract":"Pētītas iespējas izmantot jaunas izejvielas stikla šķiedras ražošanā, īpašu uzmanību pievēršot Latvijas minerālām izejvielām – devona (Bāles atradne) un juras perioda (Skudras atradne un Pīlādžu atradne) kvarca smiltīm. Apstrādājot ūdenī Skudras atradnes kvarca smiltis, krāsojošo oksīdu daudzums samazināts līdz 0,066 %. Iegūto stiklu īpašību pārbaude parādīja attīrīto Skudru atradnes kvarca smilšu izmantošanas perspektīvu E-tipa stikla šķiedras ražošanā. Veikta arī citu šihtas izejvielu izpēte: kolemanīta, kianīta, kaļķakmens.Pielietojot augstas izšķiršanas spējas skenējošo elektronu mikroskopu, diagnosticēti stikla šķiedras defektu rašanās iemesli un izzināta to novēršanas iespēja.Study of Mineral Raw Materials and Defects in Glass FibresLatvian Devonian period sand from deposit Bāle and Jurassic period sand from deposit Skudra were studied, treated and compared with sand from existing Lithuanian supplier. Investigations of Latvian quartz sand showed that sand is characterized by surface impurities, which are easy to separate combining milling and water purification. These investigations and experimental glass melts using different types of sand confirmed that it is possible to use Latvian refined sand in glass industry.Other glass raw materials – colemanite, kyanite, kaolin, limestone – also have been examined.Glass fibre breakage points were studied using SEM, FTIR and X-Ray diffractions methods. Main reasons of glass fibre breakage are non-homogeneous glass and crystalline or gaseous inclusions coming from corrosion of refractory material. This article is result of the cooperation between Institute of Silicate Materials of Riga Technical University and JSC Valmieras stikla šķiedra.Keywords – glass, glass fibre, raw materials for glass, refined sand, glass defects","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"31 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"73347989","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Latvijas minerālās izejvielas eko-keramikas izstrādei
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/MSAC-2018-0003
G. Sedmale, Māris Rundāns, Mārtiņš Randers, Ingunda Šperberga, Andris Cimmers
{"title":"Latvijas minerālās izejvielas eko-keramikas izstrādei","authors":"G. Sedmale, Māris Rundāns, Mārtiņš Randers, Ingunda Šperberga, Andris Cimmers","doi":"10.7250/MSAC-2018-0003","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0003","url":null,"abstract":"Darbā dots ieskats par iespējām izmantot Latvijas minerālās izejvielas kā bāzi vai  piedevu  keramikas  materiālu  (eko-materiālu)  izstrādei ar dažādu pielietošanas aspektu, to skaitā parādīt iespēju šo materiālu ieguves tehnoloģisko procesu optimizēšanai virzībā uz to apdedzināšanas temperatūras samazināšanu, līdz ar to reducējot kaitīgu gāzveida izmešu nonākšanu vidē. Parādīti darbu rezultāti laika periodā no 2007. g. līdz 2017. g. Tiek apskatīti un analizēti sekojoši pētījumi:neapstrādāta māla pielietošana atkritumu deponēšanas vietu noblīvēšanai;daļēji dehidratizēta māla pielietošana Cr3+, Cr6+, Zn2+ un Cu+ jonu sorbcijai, kas veidojas galvanisko procesu notekūdeņos; poru saturošas augsttemperatūras keramikas izstrāde no jauktiem izejvielu maisījumiem, kas nodrošina pietiekamu gāzveida fāzes izveidošanos keramikas apdedzināšanas procesā, veidojot poras, lai pielietotu par filtrēšanas/attīrīšanas materiālu;illīta māla piedevu izmantošana, lai pazeminātu augsttemperatūras blīvas keramikas saķepināšanas/apdedzināšanas temperatūru, iegūstot ilgspējīgu mehāniski un termiski izturīgu produktu; kā arī tehnoloģiskie procesi, kas nodrošina porainas, siltumu izolējošas keramikas materiāla ieguvi pie pazeminātām temperatūrām (ģeopolimēru metode).Mineral Raw Materials of Latvia for Development of Eco-CeramicsThe paper gives an insight into the possibilities to use Latvian mineral raw materials as a base or additives for the development of ceramic materials (eco- materials) with different application aspects, including showing the possibility of optimizing the technological processes of these materials towards the reduction of their firing temperature, thereby reducing the release of harmful gaseous effluents into the environment.The results of the works that are reported in the period were obtained from  2007 to 2017. The following studies are reviewed and analyzed: the use of untreated clay for the sealing of waste deposits; the use of partly dehydrated clay for sorption of Cr3+,6+, Zn2+ and Cu2+, which have formed in galvanic processes; the development of porous high temperature ceramics from mixes  of mineral raw materials and synthetic additives that provide a sufficient gas phase  formation in the firing process and consecutively to form pores in obtained ceramic material; the use of illite clay additives to reduce the temperature of sintering of high temperature dense mechanical and thermally durable ceramics, as well as technological processes that ensure the production of porous, heat-insulating ceramic materials at reduced temperatures (geopolymer method).","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81523541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Sola-gēla pārklājums uz emaljēta leģētā tērauda
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/msac-2018-0010
Ilona Pavlovska, G. Mežinskis, L. Bīdermanis
{"title":"Sola-gēla pārklājums uz emaljēta leģētā tērauda","authors":"Ilona Pavlovska, G. Mežinskis, L. Bīdermanis","doi":"10.7250/msac-2018-0010","DOIUrl":"https://doi.org/10.7250/msac-2018-0010","url":null,"abstract":"Darbā aprakstītas jauna materiāla un tehnoloģijas izstrādes stadijas saules enerģijas kolektoriem. Augstas jaudas saules enerģijas kolektora (AJSEK) cauruļveida materiālam jāspēj ilgstoši izturēt augstas temperatūras, neizmainot savu mikrostruktūru un nezaudējot savus sākotnējos siltumtehniskos raksturlielumus. RTU Silikātu materiālu institūta zinātnieki sadarbībā  ar LU Cietvielu fizikas institūta speciālistu izstrādājuši tehnoloģiju, kas ļauj iegūt AJSEK saules enerģiju uztverošu materiālu un spēj izturēt 600 °C temperatūru vismaz 250 dienas. Šī materiāla pamatā ir nerūsējošā tērauda cauruļveida iz- strādājums, kuram uzklāts stiklkristālisks emaljas pārklājums. Ilgstošu augsttemperatūras izturību nodrošina ne vien emaljas pārklājuma fritei pievienotās specifiskās piedevas, bet arī emaljai uzklātais sola-gēla nanodaļiņu pārklājums.Sol-gel coating on enamelled alloy steelThe stages of development of a new material and a technology for solar  collectors are described. Pipes for parabolic-trough solar collectors (PTSC) must be able to withstand high temperatures for a long time without changing their microstructure and losing their original thermal characteristics. The scientists from the Institute of Silicate Materials (Riga Technical University) together with a specialist from the Institute of Solid State Physics (University of Latvia) have developed a technology that allows the production of PTSC solar-absorbing materials capable of withstanding 600 °C temperatures for at least 250 days. This material is based on glass-crystalline enamel coating on tubular stainless steel pipes. The high-temperature resistance was ensured not only by specific additives added to the frit of enamel coating, but also by a nanosized sol-gel coating over the enamel.Keywords – enamel coatings for steel, sol-gel coatings, thermal properties, chemical properties, microhardness","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"46 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"84297200","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Minerālo saistvielu pētījumi Silikātu materiālu institūtā
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/MSAC-2018-0006
Janīna Sētiņa, Inna Juhņeviča, Jānis Baroniņš, Liene Gulbe
{"title":"Minerālo saistvielu pētījumi Silikātu materiālu institūtā","authors":"Janīna Sētiņa, Inna Juhņeviča, Jānis Baroniņš, Liene Gulbe","doi":"10.7250/MSAC-2018-0006","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0006","url":null,"abstract":"Parādīti pēdējās desmitgades pētījumi minerālo saistvielu jomā. Pētīta dažādu aktīvo ķīmisko piedevu ietekme uz betona struktūru, mehāniskajām un fizikālajām īpašībām. Novērtēta iegūto betonu korozijas izturība pret sulfātu sāļu šķīdumiem. Pētīta dažādu rūpniecisko blakus produktu – pelnu – kā pucolānu piedevas ietekme uz betona īpašībām.Investigation of Mineral Binders in the Institute of Silicate MaterialsThe influence of natural and artificial pozzolanic and micro-filler additives on the cement paste hydration process, structure, properties was studied. Different additives and chemical compositions were used: micro- and nano-silica, amorphous silicon dioxide synthesized by sol-gel method, glass powder, highly disperse sand, different types of ash. The pozzolanic activity of additives mainly depends on quantity and specific surface area, i. e., the dispersity of active SiO2 and Al2O3. Depending on the pozzolanic activity chemical additives can be used as concrete aggregates or as active additives.The influence of superplasticizer Semflow MC (SP) on microstructure and properties of concrete was investigated. The compressive strength of concrete with SP increased to 154 MPa, corresponding to HPC. The capillary absorption of water and solutions containing sulphate ions into HPC depends on amount of SP. The depth of penetration of solution in the samples decreases consistently by increasing the amount of SP. The formation of crystalline phase during maturation was analysed, and it was found that by increasing testing time the amount of portlandite decreased and calcium hydrosilicate formed. The concrete samples with low W/C ratio, pozzolanic additives and SP up to 2.5 % according mechanical and chemical properties conform to the characteristics of HPC. The investigated concrete has high chemical resistance to solutions containing sulphate ions.Keywords – binders, concrete, pozzolanic additives, ash, concrete corrosion","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"39 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76945173","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Silikātu materiālu institūts laika periodā no 2008. līdz 2018. gadam
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/msac-2018-0001
G. Mežinskis, Andris Cimmers, Inna Juhņeviča
{"title":"Silikātu materiālu institūts laika periodā no 2008. līdz 2018. gadam","authors":"G. Mežinskis, Andris Cimmers, Inna Juhņeviča","doi":"10.7250/msac-2018-0001","DOIUrl":"https://doi.org/10.7250/msac-2018-0001","url":null,"abstract":"Šajā rakstā, izmantojot Latvijas uzņēmumu datu bāzi, apzināti Latvijas Republikas uzņēmumi, kuru tehnoloģisko procesu pamatā ir silikātu, augsttemperatūras materiālu un neorganisko nanomateriālu tehnoloģijas. Apkopotas un analizētas būtiskākās izmaiņas pēdējās desmitgades laikā Rīgas Tehniskās universitātes Materiālzinātnes un lietišķās ķīmijas fakultātes Silikātu, augsttemperatūras un neorganisko nanomateriālu tehnoloģijas (SANNT) katedrā un Silikātu materiālu institūtā (SMI). Sniegtas ziņas par SANNT katedrā sagatavotajiem bakalauru, maģistru darbiem un aizstāvēto promocijas darbu skaitu. Apskatītas pētnieciskā darba finansējuma un zinātnisko pētījumu tematikas izmaiņas laika periodā no 2008. līdz 2018. gadam. Definēti SMI stratēģiskie mērķi mācību un zinātniskajā darbībā nākamajiem 5 gadiem.Institute of Silicate Materials between 2008 and 2018In this article, information about Latvian companies whose technologies are based on silicate, high temperature materials and inorganic nanomaterials was gathered from a data base of commercial companies Lursoft. The most significant changes that occurred at the Department of Silicate, High Temperature and Inorganic Nanomaterials (SHTIN) and Institute of Silicate Materials (ISM) of the Faculty of Materials Science and Applied Chemistry, Riga Technical University are summarized and analysed. Information about the number of bachelor’s, master’s degree theses, and doctoral theses defended at the department of SHTIN is provided. The changes in the research funding and scientific research topics during the period from 2008 to 2018 are considered. The strategic objectives of the ISM for teaching and research work for the next 5 years are defined.Keywords – Riga Technical University, Institute of Silicate Materials, research, teaching","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"32 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"89729045","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
Mūrējumu korozija apkārtējās vides ietekmē
Materials Science and Applied Chemistry Pub Date : 2018-11-01 DOI: 10.7250/MSAC-2018-0009
Margarita Karpe, Inta Kiriloviča, Inta Vītiņa, Laimons Timma
{"title":"Mūrējumu korozija apkārtējās vides ietekmē","authors":"Margarita Karpe, Inta Kiriloviča, Inta Vītiņa, Laimons Timma","doi":"10.7250/MSAC-2018-0009","DOIUrl":"https://doi.org/10.7250/MSAC-2018-0009","url":null,"abstract":"Būvniecībā kopš seniem laikiem izmanto neorganiskās saistvielas. Materiāli kultūrvēsturiskajos un mākslas pieminekļos pastāvīgi tiek pakļauti struktūras sairšanas procesiem, kurus paātrina arvien pieaugošais vides piesārņojums. Autotransporta dūmgāzes gaisā izdala NxOy, SO2, CO un CO2, kas saistās ar gaisa mitrumu un veido skābos lietus. Tie kopā ar putekļiem un sodrējiem nonāk uz mūrējumu virsmas, veidojot blīvu slāni. Rezultātā sākas ķīmiski korozijas procesi, veidojoties ūdenī šķīstošiem sāļiem (visbiežāk – nātrija, kālija, kalcija un magnija sulfāti). Atmosfēras mitruma svārstību un žūšanas procesu rezultātā šie sāļi kristalizējas un izraisa mūrējuma sairšanu, ko veicina bioloģiskā un fizikālā korozija.Pirmie pētījumi par mūrējumu un dabīgo akmens materiālu  koroziju  Latvijā  sākti 1984. g. RTU Silikātu tehnoloģijas katedrā. 1995. g. RTU Silikātu materiālu institūtā tika nodibināts Akmens materiālu konservācijas un restaurācijas centrs (AMKRC). Tā darbības pamatā ir kultūrvēsturisko pieminekļu zinātniskā analīze – korodējošo materiālu sastāva, struktūras, fizikālo un mehānisko īpašību izpēte.In restoration of the masonry, it is important to maintain its original composition and appearance by matching historical materials with appropriate material which is consistent both visually and in accordance with physical and chemical properties. Materials of historic-cultural and artistic monuments are constantly exposed to disintegration processes which are accelerated by ever- increasing environmental pollution (NxOy, SO2, CO and CO2). This environmental pollution reacts with moisture from air and causes acid rain. As a result, water- soluble salts (most commonly sodium, potassium and magnesium sulphates, and gypsum) are formed, causing the chemical corrosion of the masonry, which can cause its disintegration.The earliest research on corrosion of  masonry and  of  natural stone  materials  in Latvia was conducted in 1984 at the Department of Silicate Technologies, Riga Technical University. In 1995 the Center for Conservation and Restoration of Stone Materials was established at the Institute of Silicate Materials, Riga Technical University. Research by the Center includes scientific analyses of cultural-historical monuments – the study of the composition, structure, physical, and mechanical properties of corroding materials.","PeriodicalId":18239,"journal":{"name":"Materials Science and Applied Chemistry","volume":"6 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2018-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"79667730","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
引用次数: 0
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