Repository of the Institute for Material Testing (RIMS)
Not a member yet
1132 research outputs found
Sort by
Application of coal combustion byproducts in self-compacting concrete: influence on flowability
Get PDFCompared to traditional concrete, self-compacting concrete (SCC) demonstrates greater flowability, which is achieved by including an extra high percentage of ultra-fine particles. As a result, the required high paste content is obtained while the cement content is strictly limited. The coal combustion byproduct (fly ash) is one of the most efficient SCC fillers because it extends the lifecycle of SCC by improving its microstructural properties, strength, and durability. In this study, the amounts of fly ash in SCC compositions varied. The changes in physical and mechanical characteristics of fresh SCC samples related to variations in the water/binder ratio were monitored
Effective removal of the heavy metal ion Cd2+ from the structure of cementitious materials with mineral additives
Get PDFNatural zeolite and bentonite were used as mineral addi-tions to create cement-based building materials that are safe for the environment. This research focuses on the adsorptive qualities of these two clay raw materials, i.e., their propen-sity to immobilize heavy metal ions like Cd2+. The acquired results were examined using kinetic models of pseudo-first and pseudo-second order. The isotherms of Langmuir and Freundlich were examined. Zeolite and bentonite had differ-ent adsorption affinities for Cd2+ cations. Seven cement binders with various mineral additions (fly ash, zeolite, bentonite) underwent a leaching test. The adsorption and hydration mechanisms that immobilized heavy metals within cementitious composites caused leachates obtained on cement samples with the addition of fly ash and clay (either zeolite or bentonite) to contain lower concentrations of Cd2+ ions than leachates obtained on cement samples with fly ash alone
Određivanje koeficijenta prolaza toplote i otpornosti prema požaru zida izrađenog od giter-blokova
Get PDFUnazad par godina, sve više pažnje se posvećuje poboljša-nju energetske efikasnosti zgrada. Iz tog razloga se posebna pažnja obraća na dokazivanje što boljih performansi proiz-voda koji se ugrađuju u objekte. U radu je urađena numerička i eksperimentalna analiza za dobijanje koeficijenta prolaženja toplote. Analiziran je giter-blok ispunjen kamenom vunom. Eksperimentalna analiza za dobijanje koeficijenta prolaženja toplote je urađena u skladu sa standardom SRPS U. J5.060, dok je numerička analiza izvršena primenom softvera THERM, čiji se proračun bazira na standardu ISO 15099. U radu je prikazana uporedna analiza rezultata dobijenih eksperimentalnim i numeričkim putem. Eksperimentalnim putem je dobijena vrednost za otpornost prema požaru za zid izrađen od šupljih giter-blokova. Zid je ispitan u skladu sa standardom SRPS EN 1364-1
Geotehničko inženjerstvo instituta za ispitivanje materijala IMS
Get PDFRazvojem građevinskog konstrukterstva, projektovanja i izgradnje objekata pod rukovodstvom vrhunskih stručnjaka Instituta IMS, u vreme postojanja Jugoslavije, razvijala se i svest o potrebi uvođenja geotehničkog inženjerstva u okviru instituta. S obzirom da su se, u fazi projektovanja, pojavlji-vali problemi na koje je trebalo dati odgovore po pitanju fundiranja objekata, to se vremenom javljala i potreba za uvođenjem geotehničkog inženjerstva kao posebnog centra u okviru Instituta IMS. U tom smislu, paralelno sa razvojem i implementacijom geotehničkog inženjerstva, stvarana su i nova iskustva u ovoj multidisciplinarnoj kompleksnoj oblasti koja povezuje građevinarstvo i geologiju. Hronološki posma-trano geotehničko inženjerstvo u Institutu IMS može se pode-liti na tri vremenska perioda: prošlost 1948-2000.god. kao period razvoja, implementacije i projektovanja građevin-skih i geotehničkih konstrukcija, sadašnjost 2000-2023. god, period uvođenja multidisciplinarnih savremenih metoda ispi-tivanja tla i geotehničkih konstrukcija uzimajući u obzir soft-versko-hardverski inženjering, i budućnost od 2023. god. kao period značajnije primene informatičkih tehnologija i siste-ma u rešavanju geotehničkih problema
Dispersive Soils: Properties, Identification, Classification and Stabilization
Get PDFThe application of dispersive soil can result in various types of damage, and even the collapse of embanked build-ings if it is not identified. Dispersive soils cannot be uniquely identified by visual identification in the field, or by usual standard methods used for soil identification in the geo-mechanical laboratory. The paper presents the results of laboratory geomechanical tests aimed at identifying and classifying erodible dispersive fine-grained soil. The tests were carried out using the crumb test, the double hydrometer test (SCS), and the pinhole test on samples: sandy clay embankment dams of ‘Rovni’, loess from different locations (Zemun, Novi Beograd, Titel, Kelebija, Srbobran, Slanka-men, Ruma, Mali Iđoš) and kaolinite sandy clay deposits Grabež - Aranđelovac. The possibility of improving disper-sive soil by adding fly ash was also analyzed. Pinhole tests on dispersive soil samples with the addition of 10, 30 and 50 % ash showed that there was a decrease in dispersivity of natural soil for one to two dispersion classes
Application of Artificial Neural Networks in Performance Prediction of Cement Mortars with Various Mineral Additives
Get PDFThe machine learning technique for prediction and optimization of building material performances became an essential feature in the contemporary civil engineering. The Artificial Neural Network (ANN) prognosis of mortar behavior was conducted in this study. The model appraised the design and characteristics of seventeen either building or high-temperature mortars. Seven different cement types were employed. Seventeen mineral additives of primary and secondary origin were embedded in the mortar mixtures. Cluster Analysis and Principal Component Analysis designated groups of similar mortars assigning them a specific purpose based on monitored characteristics. ANN foresaw the quality of designed mortars. The impact of implemented raw materials on the mortar quality was assessed and evaluated. ANN outputs highlighted the high suitability level of anticipation, i.e., 0.999 during the training period, which is regarded appropriate enough to correctly predict the observed outputs in a wide range of processing parameters. Due to the high predictive accuracy, ANN can replace or be used in combination with standard destructive tests thereby saving the construction industry time, resources, and capital. Good performances of altered cement mortars are positive sign for widening of economical mineral additives application in building materials and making progress towards achieved carbon neutrality by reducing its emission
Ocenjivanje i verfikacija stalnosti performansi betona u skladu sa zahtevima Pravilnika za beton
No full textTechnical features of Pb-Zn slag that allow its valorization and application
No full textAccording to earlier physical-chemical and mineralogical analysis, slag from "Topionica"- Veles (Northern Macedonia) represents a potentially important raw resource. It is an inhomogeneous raw material with considerable nonferrous metal content, particularly Pb, Zn, Cu, and Ag (considered as a precious metal). This technogenic resource's mineralogical analysis revealed a very complex composition: amorphous phase, lead alloys, zinc alloys, wüstite (FeO), sphalerite, galena, cerussite, elemental silver, elemental copper, elemental iron, magnetite, spinel, rutile, hematite, troilite (FeS). The most abundant phase is an amorphous phase (glassy matrix) composed of spinel, silicate, and mixed (spinel-silicate). The sample has substantially less wüstite, that appears as skeletal inclusions in the glassy matrix. SEM investigation revealed the presence of Fe-Mn-Zn spinels in the Pb-Zn slag, as well as Pb and Zn alloys. These alloys are primarily composed of Cu. The grains of these phases are up to 100μm appearing as inclusions (usually as complex inclusions with a glassy matrix of elemental iron and wüstite). Grains bigger than 100μm in length are typically free or have simple inclusions. The biggest grains in the aforementioned stages have diameters of up to 300μm. The mineralogical study revealed that the Pb-Zn slag is a very complex raw material. It is required to investigate it in detail and establish the methods in which it can be done in order to value it and eventually apply it. Every stage of the preparation process has to be accompanied by numerous analyzes that will indicate the relevance of the preparation process and ways of concentrating useful components into commercial products
The properties of heavyweight self-compacting concrete on water penetration under pressure
No full textFly ash is a highly efficient mineral additive whose role is reflected in improvements of microstructure packing, strength and durability of non-shaped composite building materials such as self-compacting concrete (SCC). A comparative study of performances of SCC with fly ash and standard SCC with limestone filler was conducted.Additional experimental self-compacting concretes with different types of fine aggregates, fillers, and special additives for increasing freeze-thaw resistance were prepared and optimized. The correlation between percentage of barite sand and additives, and properties of SCC, were
investigated and discussed. Main topic of these article is testing the resistance of concrete to penetration of water under pressure
Analysis of the possibility of application of gabion walls for landslide rehabilitation - Case study of a landslide on the road Stolice - Krupanj at km 0+578.6 - 0+605.90
No full textU ovom radu, analiza stabilnosti, pre i posle primene tehničkih rešenja, je vršena na klizištu koje se nalazi na relaciji Stolice – Krupanj, u zapadnom delu Republike Srbije. Klizište je zahvatilo i deo saobraćajnice tako da je kretanje saobraćaja bilo otežano. Analizirano je više rešenja potpornog zida od gabionskih korpi i nivelacionog rešenja padine koja je zahvaćena klizištem. Odabir optimalnog rešenja zasnovan je na ispunjenosti dva kriterijuma: stabilnost konstrukcije i stabilnost celokupne padine. Stabilnost pre primene tehničkih mera i generalna stabilnost padine sa primenjenim merama ispitivana je metodom Janbu-a, a lokalna stabilnost metodom Bishop-a. Provera stabilnosti zida izvršena je u pogledu preturanja i horizontalnog pomeranja. Ove analize izvršene su primenom softvera GEO5 (Geotechnical software). Analitičkim putem izvršena je i analiza nosivosti zemljišta ispod potpornih zidova metodom Brinc Hansen-a. Dva rešenja ispunila su zadate kriterijume, rešenja I sa faktorm sigurnosti Fs = 1,81 i rešenje II Fs = 1,75. Analiza nosivosti zemljišta pokazala je da temeljeno tlo može bezbedno da primi opterećenje od konstrukcije u slučaju oba rešenja. Za optimalno rešenje sanacije klizišta odabrano je rešenje II.In this paper, the stability analysis before and after the application of technical solutions was performed on a landslide located on the Stolicе-Krupanj route, in the western part of the Republic of Serbia. The landslide also affected part of the road, so the movement of traffic was difficult. Several solutions of the gabion retaining wall and the leveling of the slope affected by the landslide were analyzed. The selection of the optimal solution is based on the fulfillment of two criteria: the stability of the structure and the stability of the entire slope. The stability before the application of technical measures and the general stability of the slope with the applied measures were examined using the Yanbu method, and the local stability using the Bishop method. The stability of the wall was checked in terms of overturning and horizontal movement. These analyzes were performed using GEO5 software (Geotechnical software). Analytical analysis of the load-bearing capacity of the soil under the retaining walls was carried out using the Brinc Hansen method. Two solutions met the set criteria, solution I with a safety factor Fs = 1.81 and solution II Fs = 1.75. The analysis of the bearing capacity of the soil showed that the foundation soil can safely receive the load from the structure in the case of both solutions. Solution II was selected for the optimal solution for landslide rehabilitation