Utjecaj soli zemnoalkalijskih metala na portland cement

master's thesis

• Title (english): Influence of earth alkali metal salts on portland cement
• Author: Silvia Dratibi
• Mentor: Nevenka Vrbos (mentor)
• Committee member: Nevenka Vrbos (predsjednik povjerenstva)
• Committee member: Emi Govorčin Bajsić (član povjerenstva)
• Committee member: Juraj Šipušić (član povjerenstva)
• Granter: University of Zagreb; Faculty of Chemical Engineering and Technology; Zagreb
• Defense date and country: 2021-09-20, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Chemical Engineering

Abstract

Kako bi se odredio utjecaj klorida zemnoalkalijskih metala (CaCl2∙2H2O, MgCl2∙6H2O, SrCl2∙6H2O) na svojstva modificiranog hidrauličnog veziva, pripremljeni su uzorci portland cementa PC sa dodatkom ispitivanih soli u masenim udjelima od 1-5 % na masu cementa. Pripravljeni uzorci karakterizirani su mjerenjem vremena vezanja, čvrstoće na tlak i brzine razvoja topline hidratacije. Vrijeme vezanja pripravljenog materijala određeno je Vicatovim aparatom. Čvrstoća na tlak mjerena je na laboratorijskoj hidrauličnoj preši nakon 24 sata, 3 dana, 7 dana i 28 dana hidratacije u bazenima s vodom. Toplina hidratacije mjerena je u kalorimetru tijekom 60 sati. Uzorci sa 1, 2 i 5 % dodane zemnoalkalijske soli ispitani su rendgenskom difrakcijskom analizom (XRD) i karakterizirani su infracrvenom spektrometrijom s Fourirerovom transformacijom (FTIR). Provedena mjerenja pokazala su smanjenje vremena vezanja i čvrstoće na tlak s povećanjem udjela soli, a brzina razvoja topline hidratacije povećala se povećanjem udjela CaCl2∙2H2O i SrCl2∙6H2O. Povećanje udjela MgCl2∙6H2O nije značajnije utjecalo na brzinu reakcije hidratacije.

Abstract (english)

In order to investigate the influence of earth alkaline chlorides (CaCl2∙2H2O, MgCl2∙6H2O, SrCl2∙6H2O) on modified hydraulic binder's properties, samples of portland cement with 1-5 % additions of stated salts were prepared. Setting time, compressive strength and heat of hydration were measured. Setting time of the samples was measured on Vicat apparatus. Compressive strength was measured with laboratory hydraulic press after 24 hours, 3 days, 7 days and 28 days of hydration in water tank. Calorimeter was used to measure the heat development during 60 hours. Samples with 1 %, 2 % and 5 % additions were characterized by X-ray diffractometry (XRD) and Fourier transform infrared spectroscopy (FTIR). The analysis showed the acceleration of the setting time and deterioration of compressive strength for higher salt concentrations. Heat of hydration increased with the addition of CaCl2∙2H2O and SrCl2∙6H2O. The addition of MgCl2∙6H2O did not affect the hydration rate.

• Keywords: portland cement; zemnoalkalijske soli; vrijeme vezanja; čvrstoća; toplina hidratacije
• Keywords (english): portland cement; alkaline earth metal salts; setting time; strength; heat of hydration
• Language: croatian
• URN:NBN: urn:nbn:hr:149:751401
• Study programme: Title: Materials Science and Engineering - Graduate study; Study programme type: university; Study level: graduate; Academic / professional title: magistar/magistra inženjer/inženjerka kemijskog inženjerstva (magistar/magistra inženjer/inženjerka kemijskog inženjerstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2023-04-14 11:07:52