High performance recycled aggregate concrete incorporating micro silica and synthetic macro fibre

Tijani, Ajibola Ismail (2016). High performance recycled aggregate concrete incorporating micro silica and synthetic macro fibre. University of Birmingham. Ph.D.

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Abstract

The continuous global demand for infrastructure due to persistent increase in population growth implies that more aggregate and cement would be required in concrete production. This would eventually lead to more extraction and depletion of natural resources and increased carbon emission. The aim of this research work was to develop high performance concrete using recycled coarse aggregate, microsilica, and synthetic macro fibre with the object to boost higher use of recycled coarse aggregate in the construction industry.
Concrete was designed for 28-day compressive cube strength of 50MPa, high workability (60-180mm) and a constant water-cement ratio of 0.39. Microsilica was incorporated up to 20% of cement content at 5% intervals, while the natural coarse aggregate substitution by recycled coarse aggregate ranges between 0 - 100% at 25% interval. Workability, compressive cube strength, tensile splitting strength, flexural strength, static elastic modulus, and water permeability tests including fatigue assessment were conducted respectively.
Results confirmed that, the incorporation of 15% microsilica with 50% recycled coarse aggregate fraction produced 28-day compressive cube strength which exceeds the characteristics and target mean compressive cube strength of the control mix which are 50MPa and 63.1MPa respectively. The result suggests that there is a potential to increase the optimum fraction of recycled aggregate from 30-50% in concrete.

Type of Work:

Thesis (Doctorates > Ph.D.)

Award Type:

Doctorates > Ph.D.

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