The flow characteristics of a fresh condition, conventional and self-compacting macro-concrete, the mechanical properties of high-strength and medium-strength macro-concrete were studied, including post-cracking behavior, compressive strength and electrical resistivity.
Deterioration of concrete structures due to the corrosion of embedded steel is a well-known universal problem. Norway with its numerous bridges, ports, offshore and floating structures along its coastline, is also encountered with corrosion degradation.
The harsh environment of the Norwegian Sea regarding its low temperature, wind, and waves, makes the design and construction of marine structures more demanding. In recent years, usage of sustainable composite materials in the field of structural engineering has been rising.
The usage of natural fibre reinforced polymer materials in the form of reinforcement bars or macro fibres with a low density, high strength, and excellent corrosion resistance, gives us better choices for the design and construction of marine structures.
Our knowledge about the fibre reinforced self-compacting concrete has increased as a result of introducing it as a building material some decades ago. However, more research is still needed when it comes to the application of new types of fibres.
This thesis is a result of this need, whereby the author has done two series of experimental programmes regarding the subject. In the first series, the flow characteristics of fresh state, conventional and self-compacting macro basalt fibre concrete were studied.
In the second series, mechanical properties of high performance and medium strength macro basalt fibre concrete including the post-cracking behaviour, compressive strength and electrical resistivity were in focus. The findings were presented in three appended papers and the extended summary composing this thesis.
Additionally, the thesis presents an overview of the design procedure of floating concrete structures and the possibility of using macro basalt fibre concrete via a case study. The author’s literature review shows that basalt fibres have an adequate resistance against alkali environment of the concrete matrix and corrosive environment of seawater.
List of papers
Chapter 1 – Introduction
1.2 Aims and Limitations
1.3 Outline of the Thesis
Chapter 2 – Basalt Fibre Reinforced Polymers (BFRPs)
2.2 History of Using Basalt
2.3 Chemical Composition of Basalt Fibres
2.4 Production Process of Continuous Basalt Fibres
2.5 Mechanical Properties of Basalt Fibres
2.6 Basalt Fibre Reinforced Polymer Composites
2.7 Degradation in Seawater
2.8 Degradation in Alkaline Environment
Chapter 3 – Fibre Concrete
3.1 Post-Cracking Behaviour of Fibre Concrete
3.2 A Brief Overview on the Design Methods of Fibre Concrete
Chapter 4 – Floating Concrete Structures
4.1 Floating Structures
4.2 Loading and Design Principles of Floating Concrete Vessels
4.3 Fatigue in Marine Concrete Structures
4.4. A Case Study
Chapter 5 – Summary of Methods
5.1 Self Compacting Concrete Mix Design
5.2 Experimental Methods for Fresh Concrete
5.3 Experimental Methods for Evaluation of Hardened Concrete
Chapter 6 – Results and Discussions
6.1 Results from the Evaluation of Fresh Fibre Concrete
6.2 Results from the Assessment of Hardened Fibre Concrete
Chapter 7 – Conclusions
Chapter 8 – Further Research
Mohammadi Mohaghegh, Ali
KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures. NTNU i Ålesund.
KTH Royal Institute of Technology Department of Civil and Architectural Engineering Division of Concrete Structures Stockholm, Sweden, 2016