Vpliv notranjih rezervoarjev vode in vsebnosti vlaken na krčenje betonov visoke trdnosti : diplomska naloga

Udir, Rok (author), Saje, Drago (mentor)

Betoni visoke trdnosti imajo majhno vodovezivno razmerje, zato je njihovo zgodnje avtogeno krčenje večje. V diplomski nalogi smo opisali zmanjševanje le-tega s pomočjo predhodno namočenega lahkega agregata, različnih frakcij in jeklenih vlaken. V okviru laboratorijskih raziskav smo merili avtogeno in celotno krčenje betonov visoke trdnosti. Iz dobljenih vrednosti smo izračunali prispevek krčenja zaradi sušenja. Obravnavali smo tudi tlačne trdnosti strjenega betona posameznih betonskih mešanic in opazovali vpliv vsebnosti lahkega agregata in jeklenih vlaken na njeno velikost. Največji doprinos k zmanjšanju krčenja je imela notranja nega s predhodno namočenim lahkim agregatom. Ugotovili smo, da se je beton, ki je vseboval jeklena vlakna in notranje rezervoarje vode v obliki predhodno z vodo namočenega lehnjaka, frakcije 24 mm, krčil najmanj in dosegal največje tlačne trdnosti glede na primerjalne betone.

• Language: Slovenian
• Keywords: gradbeništvo, diplomska naloga, VSŠ, OG-MK, beton visoke trdnosti, vlaknasti betoni, notranja nega, lahki agregat, tlačna trdnost, krčenje betona
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [R. Udir]
• Year: 2014
• Number of pages: X, 56 str.
• PID: 20.500.12556/RUL-32375
• UDC: 624.012.4(043.2)
• COBISS.SI-ID: 6814305
• Publication date in RUL: 10.07.2015

Secondary language

• Language: English
• Title: The influence of internal water reservoirs and steel fibres content on shrinkage of high strength concrete

Abstract

Due to its low water/cement ratio, high-strength concrete has a more pronounced early-age autogenous shrinkage. This thesis studies how to mitigate that by means of pre-soaked lightweight aggregate, various fractions and steel fibers. In the experimental part of the study, we measured the autogenous and total shrinkage of high-strength concrete, and used the results to calculate the contribution of drying shrinkage. We also measured the compressive strength of hardened concrete mixtures, and studied the influence of lightweight aggregate and steel fiber content on the compressive strength. Internal curing with pre-soaked lightweight aggregate proved to be the best shrinkage mitigator. We found out that the concrete which was reinforced with steel fibers and included internal water reservoirs in the form of pre-soaked tuff of 2 to 4 mm had the lowest shrinkage and the highest compressive strength of all the compared concrete mixtures.

• Keywords: high strength concrete, fibre reinforced concrete, internal curing, lightweight aggregate, compressive strenght, concrete shrinkage