Access Type

Open Access Dissertation

Date of Award

January 2020

Degree Type

Dissertation

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

First Advisor

Hwai-Chung . Wu

Abstract

Among the most important advances of research and technological development for viable applications of coal-fired fly ash, the development of new inorganic polymeric materials, named alkali activated cement or “Geopolymers”, seems to gain increasing attention during the last twenty years. The present investigation intends to study the effect of hot weather environments (either by changing relative humidity and temperature is kept constant, or by changing temperature but relative humidity is maintained same) on the durability performance of geopolymer concrete beams and columns. The study include the long term influence of moisture, high temperature, and combined hygrothermal conditions on the mechanical properties of geopolymer beams and columns.

An extensive experimental research has been done throughout implement and test several sets of specimens include regular concrete beams and columns, and geo-polymer concrete beams and columns exposed to different environmental conditions.

Also, two and three-dimensional extended finite element method (X-FEM) is developed and implemented in the ABAQUS-CAE package to predict the behavior of both regular concrete beams and columns and geo-polymer concrete beams and columns exposed to different environmental conditions.

In addition, analytical calculations for regular concrete and geo-polymer concrete were developed to predict the long-term strength of regular concrete and geo-polymer concrete that exposed to various environmental conditions. William-Landel-Ferry (WLF) equation was employed here to develop the shift factor for regular concrete and geo-polymer concrete exposed to different environmental conditions. The shift factors were determined empirically based on experimental test results.

To confirm the validity of the analysis process and the solution obtained, the flexural load and compressive load were acquired using the analytical calculations compared to experimental results and FE analysis.

Finally, conclusions and suggestions for future study research are presented.

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