Vpliv vrste agregata in mineralnega dodatka na reološke in mehanske lastnosti lahkovgradljivega betona : diplomska naloga

Lešnik, Alen (author), Bokan-Bosiljkov, Violeta (mentor), Prinčič, Tina (co-mentor)

Diplomsko delo je zajemalo preiskave svežega in strjenega lahkovgradljivega betona različnih sestav z enakim vodo-vezivnim razmerjem. Preiskovali smo štiri različne mešanice betonov, ki so se medsebojno razlikovale po vrsti agregata in/ali veziva. Vsi betoni so bili pripravljeni z uporabo kemijskega dodatka – superplastifikatorja nove generacije. V preiskave smo vključili dve vrsti drobljenega karbonatnega agregata, Portland cement ter mineralni dodatek, elektrofiltrski pepel, ki je nadomestil 20 % cementa v vezivu. V prvem delu preiskav smo vplive agregatov in mineralnega dodatka preverjali preko reoloških lastnosti svežih betonskih mešanic v časovnem intervalu ene ure po končanem mešanju. S posedom in razlezom smo preskušali konsistenco svežega betona, s porozimetrom pa vsebnost por v mešanici. Z reometrom smo določili napetost na meji tečenja in plastično viskoznost mešanic. Drugi del preiskav je bil namenjen določanju mehanskih lastnosti. Na strjenih vzorcih betona smo po 3-eh, 28-ih in 90-ih dneh določali njihove tlačne trdnosti, module elastičnosti in odpornost proti prodoru vode. Nazadnje smo, s pomočjo rezultatov preiskav, primerjali omenjene karakteristike ter ocenili vplive različnih vrst agregata in uporabljenega mineralnega dodatka na karakteristike svežega in strjenega b

• Language: Slovenian
• Keywords: gradbeništvo, diplomska dela, UNI, lahkovgradljiv beton, vrsta agregata, elektrofiltrski pepel, obdelavnost betonana, trdnost betona, elastični model betona, vodoprepustnost betona, slv, graduation thesis, civil engineering, highly flowable concrete, aggregate type, fly ash, workability of concrete, compressive strengtht of concrete, modulus of elasticity of concrete, permeability of concrete
• Work type: Undergraduate thesis
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Lešnik]
• Year: 2012
• Number of pages: XIII, 71 str.
• PID: 20.500.12556/RUL-32590
• UDC: 66.018:691.3(043.2)
• COBISS.SI-ID: 6050657
• Publication date in RUL: 10.07.2015

Secondary language

• Language: English
• Title: Influence of aggregate and mineral additive type on the rheological and mechanical properties of highly flowable concrete

Abstract

This thesis deals with the properties of fresh and hardened highly flowable concrete of various compositions with the same water-binder ratio. We examined four different concrete mixtures which differed by the type of aggregate and/or binder. All concrete mixtures were prepared with a polycarboxylate superplasticizer. We studied the influence of two types of crushed carbonate aggregate, i.e. Portland cement CEM I and mineral additive fly ash, with witch we replaced 20 % of the Portland cement in the binder. In the first part of the study we tested the influences of the type of aggregates and mineral additive through rheological properties of fresh concrete mixtures in the period of one hour after mixing. Using slump test and flow table test we estimated the consistency of fresh concrete. We used porosimeter to determine the amount of air bubbles in concrete and rheometer to measure yield stress value and plastic viscosity of the concrete mixtures. In the second part of the study we determined mechanical properties. Using samples of hardened concrete, we evaluated its compressive strength, modulus of elasticity and resistance to penetration of water after 3, 28 and 90 days. The results of the study were used to compare the above mentioned properties and to evaluate the influences of various types of aggregates and mineral additive on the properties of fresh and hardened concrete.