Usporedba koeficijenta difuzije cementne paste s različitim sastavom veziva

undergraduate thesis

• Title (english): Comparison of chloride diffusion of cement paste with different binder composion
• Author: Marijana Krakan
• Mentor: Marijana Serdar (mentor)
• Mentor: Kristina Ana Škreb (komentor)
• Committee member: Ivan Gabrijel (predsjednik povjerenstva)
• Committee member: Marijana Serdar (član povjerenstva)
• Committee member: Kristina Ana Škreb (član povjerenstva)
• Granter: University of Zagreb; Faculty of Civil Engineering; (Materials); Zagreb
• Defense date and country: 2021-09-07, Croatia
• Scientific / art field, discipline and subdiscipline: TECHNICAL SCIENCES; Civil Engineering

Abstract

Koeficijentom difuzije klorida definirana je otpornost betona prodoru klorida u morskom okolišu. Kod kemijskih mehanizama degradacije, u fokus dolazi problem difuzije klorida u cementnoj pasti. Osnovni cilj ovoga rada je istražiti povezanost koeficijenta difuzije dobivenog mini migracijom s kemijskim parametrima korištenih materijala. Korišteno je sedam mješavina uključujući obični Portland cement, te mješavine sa zamjenama cementa letećim pepelom, letećim pepelom i vapnencem, glinom, glinom i vapnencem te kvarcom. Statističkim metodama uspostavljene su korelacije između dobivenih rezultata. Prema dobivenim rezultatima i provedenim statističkim metodama, najpovoljniju vrijednost prodora klorida na razini cementne paste ostvaruje mješavina sa zamjenom dijela cementa s 30% letećeg pepela i 15% vapnenca, dok su nakon ove mješavine po otpornosti na prodor klorida mješavine s 30% gline. Pravilnim odabirom masenih udjela pojedinih kemijskih sastojaka u mješavinama može postići povoljnija vrijednost koeficijenata difuzije – kao što je slučaj kod pucolana. Degradacija betona u agresivnom okolišu ne može se u potpunosti spriječiti, ali pravilnim odabirom udjela zamjene cementa u mješavini moguće je utjecati na poboljšanje otpornosti materijala na agresivne čimbenike iz okoliša, te time postići veću trajnost konstrukcija tijekom njihovog uporabnog vijeka.

Abstract (english)

The resistance of concrete to chloride penetration in the marine environment is defined by the chloride diffusion coefficient. In chemical mechanisms of degradation, the focus comes on the problem of chloride diffusion in cement paste. The main goal of this study was to investigate the relationship between the diffusion coefficient and the chemical and physical parameters of the materials used. Seven mixes with different binder composition were used, including ordinary Portland cement, mixtures with replacement of cement with fly ash, fly ash and limestone, clay, clay and limestone and quartz. The most favorable value of chloride penetration at the level of cement paste is achieved by replacement of cement with 30% fly ash and 15% limestone, and by replacement of cement with 30% of clay. Present study also showed that by using the correct choice of mass fractions of individual chemical constituents in mixtures a more favorable value of diffusion coefficients can be achieved. The concrete degradation in aggressive environment can never be fully prevented, but by proper selection of the proportion of cement replacement in mixture it is possible to improve material resistance to aggressive environmental factors, and thus achieve greater durability of structures throughout their service life.

• Keywords: cement; alternativna veziva; leteći pepeo; glina; mini – migracija
• Keywords (english): cement; alternative binders; fly ash; clay; mini – migration
• Language: croatian
• URN:NBN: urn:nbn:hr:237:437591
• Study programme: Title: Civil Engineering; Study programme type: university; Study level: undergraduate; Academic / professional title: sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka građevinarstva (sveučilišni/a prvostupnik/ prvostupnica (baccalaureus/baccalaurea) inženjer/inženjerka građevinarstva)
• Type of resource: Text
• File origin: Born digital
• Access conditions: Closed access
• Created on: 2022-03-31 08:01:11