Location
University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
Keywords
Carbon nanofibres (CNF); Ultra-High-Performance Cementitious Composites (UHPCC); Nano-engineered; Porosity; Durability; Compressive Strength
Abstract
Ultra-high-performance concrete (UHPC) is known for exhibiting excellent strength and a more durable matrix compared to conventional concrete. Typically UHPC consists of carefully selected constituent materials of: ultrafine graded sand, silica fume (or other alternative binders), steel micro-fibres, and ordinary (or special blends) Portland cement. This study was initiated to synthesize a new blend of Ultra-high-performance cementitious composite (UHPCC) with compressive strength higher than 150 MPa under normal curing conditions, and to investigate the influence of two different sources of carbon nanofibres (CNF) on its strength, durability and microstructure properties. Several mix designs with different CNF percentages were designed, optimised and analysed to obtain the optimal proportion for the UHPCC, and their strength development were monitored up to 28 days. Subsequently, the durability performance of the selected UHPCC mixes were characterised though the rapid chloride permeability, Mercury Intrusion Porosimetry and water penetration tests. It was found that a stable dispersion with low CNF percentage (0.06%wt) was able to improve the water penetration, lower the rapid chloride permeability and reduced the pore sizes of the UHPCC matrix. The overall findings of the research assert that a stable dispersion of CNF contributes in positive effect on the strength and durability characteristics of UHPCC, and is feasible to enhance overall microstructure and contribute to a denser matrix. This study is part of the larger research programme to synthesize an innovative UHPCC mix for specialised applications for structures under impulsive loadings.
Included in
Strength and Durability Performance of Ultra-High-Performance Cementitious Composite Enhanced with Carbon Nanofibres
University of Leeds, Leeds, West Yorkshire, LS2 9JT, United Kingdom
Ultra-high-performance concrete (UHPC) is known for exhibiting excellent strength and a more durable matrix compared to conventional concrete. Typically UHPC consists of carefully selected constituent materials of: ultrafine graded sand, silica fume (or other alternative binders), steel micro-fibres, and ordinary (or special blends) Portland cement. This study was initiated to synthesize a new blend of Ultra-high-performance cementitious composite (UHPCC) with compressive strength higher than 150 MPa under normal curing conditions, and to investigate the influence of two different sources of carbon nanofibres (CNF) on its strength, durability and microstructure properties. Several mix designs with different CNF percentages were designed, optimised and analysed to obtain the optimal proportion for the UHPCC, and their strength development were monitored up to 28 days. Subsequently, the durability performance of the selected UHPCC mixes were characterised though the rapid chloride permeability, Mercury Intrusion Porosimetry and water penetration tests. It was found that a stable dispersion with low CNF percentage (0.06%wt) was able to improve the water penetration, lower the rapid chloride permeability and reduced the pore sizes of the UHPCC matrix. The overall findings of the research assert that a stable dispersion of CNF contributes in positive effect on the strength and durability characteristics of UHPCC, and is feasible to enhance overall microstructure and contribute to a denser matrix. This study is part of the larger research programme to synthesize an innovative UHPCC mix for specialised applications for structures under impulsive loadings.
