Assessing the characteristics of self compacting concrete with and without steel fibre reinforcement

Mimoun, Abdulkarim 2023. Assessing the characteristics of self compacting concrete with and without steel fibre reinforcement. PhD Thesis, Cardiff University. Item availability restricted.

Preview	PDF (Thesis) - Accepted Post-Print Version Download (11MB) | Preview
	PDF - Supplemental Material Restricted to Repository staff only Download (245kB)

Abstract

Although self-compacting concrete (SCC) with or without fibre reinforcement has been developed beyond research laboratory investigations and has now become an industrial product, its physical characteristics with respect to the fresh and hardened states behaviour and performance are not yet comprehensively understood. It is necessary to explore ways to enhance the performance of SCC (without or with fibre) to make it a more sustainable alternative to vibrated concrete (VC). This thesis focuses on the research findings related to the behaviour of SCC (without or with fibre) in fresh and hardened states. This research consists of four main parts. In the first part, SCC, or SCC with steel fibre reinforcement (SCSFRC) was explored, and it was demonstrated that SCC and SCSFRC are extensively influenced by the characteristics of components and their proportions. Therefore, optimization of SCC mix design requires to identify robust methods for proportioning components. This study aimed to develop a simple and rational approach for designing SCC (without and with fibre) mixes based on the required target plastic viscosity and compressive strength. The plastic viscosity of an SCC (without and with fibre) mix was estimated using a micromechanical procedure to develop this rational approach. Investigational work was performed indicating the validity of this mix design method via a series of SCC mixes in term both the fresh and hardened states. The test mixes were found to meet the essential SCC and compressive strength standards, thus completely validating the adopted mix proportioning method. Therefore, this approach significantly decreases the extent of laboratory work, materials, and testing time required to achieve a mix that meets the required specifications. The second part focused on the other important properties of fresh SCC, including SCSFRC mixes with various volume fractions of components, based on the desired target plastic viscosity and compressive strength of the mix. For SCC mixes without steel fibre, the fulfilment of flow and cohesiveness criteria was found to be satisfactory for the chosen mix design. However, for the design of SCC mixes with steel fibre, it was found that they had to additionally meet the passing and filling ability criteria. The third part addressed the properties of hardened SCC: specific fracture energy, tensile strength, and modulus of elasticity. These were studied by detailed investigation of the role of several parameters, comprising steel fibre volume, paste to solids ratio, water to cementitious material ratio, and strength grade of SCC mixes without or with fibre. It was found that SCC with higher volume fraction of steel fibre performs comparatively better in hardened state. Nonetheless, the amount of fibre content is restricted by workability of the SCC mix. The fourth part introduces numerical simulation of flow of SCC with steel fibre in the slump flow and L-box tests. This simulation was performed by an incompressible mesh-less smooth particle hydrodynamics (SPH) methodology. An appropriate Bingham-type constitutive model was coupled with the Lagrangian momentum and continuity equations to simulate the flow. The numerical simulation results were compared with the actual slump flow and L-box tests carried out on several SCC with fibre mixes, and the comparison revealed that this methodology is very well suited for predicting the flow behaviour of SCC in terms of passing and filling abilities of fibre. On the other hand, the simulation of SCC mixes with steel fibre concentrated on the distribution of fibres and their orientations during the flow in three dimensional configuration. The SPH simulation procedure can therefore substitute the time consuming laboratory investigation of both flow and L-box tests, thereby minimizing time, effort, and material costs.

Item Type:	Thesis (PhD)
Date Type:	Completion
Status:	Unpublished
Schools:	Engineering
Uncontrolled Keywords:	1). Self-compacting concrete (SCC) 2). Self-compacting steel fibre reinforced concrete (SCSFRC) 3). Design mix 4). Portland limestone cement 5). Limestone powder 6). Steel fibre 7). Smooth particle hydrodynamics (SPH)
Date of First Compliant Deposit:	26 October 2023
Last Modified:	26 Oct 2024 01:30
URI:	https://orca.cardiff.ac.uk/id/eprint/163119

Actions (repository staff only)

Edit Item