Date of Award

2019

Publication Type

Doctoral Thesis

Degree Name

Ph.D.

Department

Civil and Environmental Engineering

First Advisor

Sreekanta Das

Keywords

Durability, ECC, Fibres, Pulp, SEM, Strength

Rights

info:eu-repo/semantics/embargoedAccess

Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Abstract

This dissertation presents the results obtained through a comprehensive experimental work that was carried out in two different phases. Phase I determined the mechanical and durability performance of cementitious composites reinforced Kraft pulp fibres. Two engineered fibers, along with a commercially available unmodified fiber, were used in reinforcing cementitious materials. These fibres are called mechanically modified fibre and chemically treated fibre, and these are not yet commercially available. This study was completed to determine the strength, durability, and interfacial properties of the reinforced cementitious composites. Test results showed an increase in the permeability characteristics for the reinforced concretes. Hence, these fibres reduced the compressive strength and durability of reinforced concretes as compare to the unreinforced concrete. However, the two engineered fibres performed better than the unmodified fibre in terms of compressive strength, chloride ion permeability and water sorptivity. Further, the drying shrinkage strain was reduced considerably when only 1% chemically treated fiber was added. In phase II, a study was completed to experimentally determine the influence of partial and full replacement of slag with fly ash on the mechanical and durability performance of engineered cementitious composites. Test results showed that mixtures containing slag exhibited strain-hardening like behaviour and a comparable ductility property as engineered cementitious composites containing fly ash. Further, slag blends were found to be significant in reducing permeability in terms of rapid chloride penetration, sorptivity, and water absorption at both 28 and 90 days. However, higher drying shrinkage strains were observed for mixtures containing slag when compared to fly ash mixtures.

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