Vpliv metakaolina na lastnosti injekcijskih mas na osnovi naravnega hidravličnega apna : diplomska naloga

Vavričuk, Anja (author), Bokan-Bosiljkov, Violeta (mentor), Dolenec, Sabina (comentor)

Sanacija poškodb zidov, ki so posledica staranja materiala in posledičnega zmanjšanja nosilnosti zaradi nepovezanosti gradnikov zidu, se najpogosteje izvaja z sistematičnim injektiranjem. Ta tehnika je ena izmed manj invazivnih in ohranja največ značilnosti prvotnega zidu, kar je še posebej pomembno pri obnovi objektov kulturne dediščine. Ker lahko pogosto uporabljene injekcijske mase na osnovi cementa vodijo v nadaljnjo poškodbo zidov, se v konservatorsko-restavratorski praksi vse bolj uporabljajo injekcijske mase na osnovi apna. Čeprav so apnene mešanice s konservatorskega vidika primernejše, pa so pomanjkljive z vidika utrditve konstrukcijskih elementov. Z namenom, da bi odpravili te pomanjkljivosti, smo mase, ki smo jih analizirali v okviru preiskav, pripravili na osnovi naravnega hidravličnega apna, ki smo ga v masnih deležih 10 %, 20 % in 30 % nadomestili z metakaolinom. V študiji smo uporabili dva različna metakaolina, ki sta se razlikovala predvsem v specifični površini. Preiskave, ki smo jih izvedli na svežih masah pri konstanti pretočnosti in na strjenih masah, so pokazale, da večji delež metakaolina povečuje potrebo po vodi svežih mas ter tlačno trdnost in poroznost pri strjenih masah. Večji delež metakaolina je tudi rahlo povečal vodozadržnost, ni pa imel večjega vpliva na spremembo prostornine in izločanje vode. Pri primerjavi rezultatov glede na uporabo različnih metakaolinov se je za bolj reaktivnega izkazal metakaolin, ki ima večjo specifično površino in manj nereaktivnega mullita. Rezultati kažejo, da kombinacija naravnega hidravličnega apna in metakaolina ustvarja stabilno injekcijsko maso, ki ima potencial doseganja zadovoljivih trdnosti in obdelavnosti ter s tem uporabe v konservatorskorestavratorski praksi.

• Language: Slovenian
• Keywords: gradbeništvo, diplomska naloga, OG-MO, naravno hidravlično apno, metakaolin, injekcijske mase, hidratacijski produkti, kulturna dediščina
• Work type: Bachelor thesis/paper
• Typology: 2.11 - Undergraduate Thesis
• Organization: FGG - Faculty of Civil and Geodetic Engineering
• Place of publishing: Ljubljana
• Publisher: [A. Vavričuk]
• Year: 2016
• Number of pages: XVIII, 39 str., 4 pril.
• PID: 20.500.12556/RUL-85913
• UDC: 691.51:666.92(043.2)
• COBISS.SI-ID: 7812961
• Publication date in RUL: 30.11.2016

VAVRIČUK, Anja, 2016, Vpliv metakaolina na lastnosti injekcijskih mas na osnovi naravnega hidravličnega apna : diplomska naloga [online]. Bachelor’s thesis. Ljubljana : A. Vavričuk. [Accessed 18 May 2025]. Retrieved from: https://repozitorij.uni-lj.si/IzpisGradiva.php?lang=eng&id=85913

Secondary language

• Language: English
• Title: Influence of metakaolin on properties of injection grouts prepared by natural hydraulic lime

Abstract

Masonry degradation caused by aging of the material and consequent reduction in loadbearing capacity due to the lack of connection between masonry elements is commonly repaired by injecting. This technique is one of the less invasive ones and it preserves most of the characteristics of the original masonry, which is especially important in conservationrestoration of cultural heritage. While injection grouts based on cement can result in further degradation of masonry, lime-based grouts have become increasingly used in conservationrestoration practice. Although lime grouts are more compatible with historic materials, they are deficient in terms of consolidation of the structural elements. In order to overcome these shortcomings, different grout mixtures were prepared by mixing natural hydraulic lime and two different types of metakaolin at substitution rates of 10 %, 20 % and 30 % by mass. The test results of grout properties showed that higher metakaolin content increases the water demand of the fresh mixtures as well as compressive strength and porosity of the hardened mixtures. The addition of metakaolin at constant fluidity slightly enhanced water retention, but had no significant impact on volume change and bleeding. When comparing two different metakaolins that were used, higher compressive strengths were measured in the case of the grouts which included the metakaolin with higher surface area and smaller quantity of unreactive mullite. The results show that the combination of natural hydraulic lime and metakaolin generates a stable grout, which has the potential to achieve considerable strengths, the necessary workability as well as use in conservation- restoration practice.

• Keywords: natural hydraulic lime, metakaolin, injection grouts, hydration products, cultural heritage