Thesis Defense - Gisu Güldoğan (MSCE)

Gisu Güldoğan - M.Sc. Civil Engineering

Asst.Prof. Zeynep Başaran Bundur – Advisor

Date: 10.06.2020

Time: 11:30

Location: This meeting will be held ONLINE. Please send an e-mail to gizem.bakir@ozyegin.edu.tr in order to participate in this defense.

Bio-Based Rheology Modifying Agents for Cement-Based Materials

Thesis Committee:

Asst.Prof. Zeynep Başarn Bundur,  Özyeğin University

Asst.Prof. İlknur Eruçar,  Özyeğin University

 Prof. Nilüfer Özyurt Zihnioğlu, Boğaziçi  University

Abstract:

Recent developments in the construction sector lead to the possible implementation of advanced manufacturing techniques of cement-based materials with superior fresh state qualities over conventional concrete; such as homogeneity, flowability, and high workability. These parameters can be obtained through the use of “Rheology Modifying Agents”, like various chemical and mineral additives including superplasticizers, high range water reducers (HRWR), and viscosity modifying agents (VMA) to increase flowability without causing segregation and bleeding in concrete. This study aims to develop bio-based viscosity modifying agents (bio-VMAs) for cement-based materials particularly for highly flowable mixes. Two different approaches were followed to achieve this goal. First, bacterial cells and biofilms were used as bio-VMAs. Then, a 2-part bio-VMA was developed by immobilizing bacterial cells on locally available porous minerals. The performance of designed bio-VMAs was mainly evaluated through rheological analysis and mini-slump test. A further compressive strength testing was done for mortar samples containing 2-part bio-VMA. With these approaches, the yield stress of cement paste could be increased by the addition of bio-VMAs. The use of 2-part bio-VMAs was more promising in terms of improving rheology without sacrificing performance. 

Bio: 

Gisu Güldoğan was born in Bursa, March 1994. She received her BCs. degree from Civil Engineering Department, Ozyegin University (OzU). She continued her education with an M.Sc. Civil Engineering at OzU. During her masters, she worked as a research assistant in OzU Construction Materials Research Group (CMRG) focusing on sustainable cementitious systems including biological additives and rheology. Through her degree, she published 2 proceedings and presented her work in the American Concrete Institute Convention in 2019.