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The reduction of greenhouse gas emissions towards net zero carbon, through the efficient use of resources, is among the grand challenges. Buildings offer an unparalleled opportunity in terms of conservation of resources and energy performance improvement. Increasing amounts of bio-based insulation materials are being utilised in buildings. The aim of this thesis was to develop a bio-based low carbon construction composite based on local miscanthus shiv from the Taunton area (Somerset, UK) and investigate its performance properties as an innovative insulation material. The materials development approach included a proposal of a mix design methodology, a selection of mineral binders and an experimental investigation of the chemical, mineralogical and microstructural interactions between the binders and miscanthus bio-aggregates. The performance characterisation included strength development, thermal and moisture transfer properties, and acoustic optimisation. The investigated mineral binders consisted of a blend of 75% hydrated lime and 15% natural hydraulic lime, whilst the remaining 10% was either Portland cement or pozzolanic additions (ground granulated blast-furnace slag and fly ash). Mix designs were produced using a binder to aggregate ratio of 1.5-2.0 and raw miscanthus shiv and testing samples were cured in indoor air conditions for 28 to 90 days. Samples exhibited external shell hardening and inner core softening ('powdering') for some mixes. The chemical and mineralogical analysis showed low levels of carbonation and hydration in the range of 10.0-17.1% and 0.6-1.4%, respectively at 28 days of curing. In terms of strength development, formulated lime (FLA3.5) exhibited significantly higher strength values compared to simple, binary, and ternary lime binders. This was due to a coexistence of hydration and carbonation. These results were corroborated by thermogravimetric and x-ray diffraction analysis results. Overall, binders incorporating mineral additions (slag, fly ash and cement), exhibited higher strength than hydrated lime and binary blends of hydrated lime and natural hydraulic lime. In the range of the investigated binder to aggregate ratio (b/a), the reduction of the b/a ratio from 2.0 to 1.5 has exhibited a rather low effect on strength development, particularly after 28 days. Overall, the developed miscanthus concrete has achieved compressive strength values of 207 kPa after 28 days and 482 kPa after 90 days, which are comparable to those of typical vegetal concretes with similar density values. The developed miscanthus lime composites exhibited dry thermal conductivity values of 70-77 mW.m-1.K-1. Therefore, miscanthus shiv can be effectively used in thermal envelopes of low carbon buildings. Miscanthus concrete composite recorded interesting moisture buffer values in the range of 2.06-2.25 g/m2.%RH, confirming its ability to contribute to modulating internal humidity levels in buildings. Acoustic transmission loss values in the range of 10-30 dB were recorded, suggesting beneficial contribution towards acoustic comfort in new builds and retrofits. The environmental assessment of miscanthus concrete has shown that miscanthus concrete can capture and store an average of 135 kgCO2/m3, suggesting a high potential of miscrete for use as a carbon sink in buildings.

Very limited research studies have been conducted to examine the behaviour of rubberised concrete (RuC) with nano silica (NS) and addressed the acoustic benefits of rubberised concrete. The current research investigates the effect of incorporating colloidal nano silica on the mechanical, thermal and acoustic properties of Rubberised concrete and compares them with normal concrete (NC). Two sizes of rubber were used RA (0.5 - 1.5 mm) and RB (1.5 - 3 mm). Fine aggregate was replaced with rubber at a ratio of 0%, 10%, 20% and 30% by volume, and NS is used as partial cement replacement by 0%, 1.5% and 3%. A constant water to cement ratio of 0.45 was used in all concrete mixes. Various properties of rubberised concrete, including the density, water absorption, the compressive strength, the flexural strength, splitting tensile strength and the drying shrinkage of samples was studied as well as thermal and acoustic properties. Experimental results of compressive strength obtained from this study together with collected comprehensive database from different sources available in the literature were compared to five existing models, namely Khatib and Bayomy- 99 model, Guneyisi-04 model, Khaloo-08 model, Youssf-16 model, and Bompa-17 model. To assess the quality of predictive models, influence of rubber content on the compressive strength is studied. An artificial neural network (ANN) models were developed to predict compressive strength of RuC using the same data used in the existing models. Three ANN sets namely ANN1, ANN2 and ANN3 with different numbers of hidden layer neurons were constructed. Comparison between the results given by the ANN2 model and the results obtained by the five existing predicted models were presented. A finite element approach is proposed for calculating the transmission loss of concrete, the displacement in the solid phase and the pressure in the fluid phase is investigated. The transmission loss of the 50mm concrete samples is calculated via the COMSOL environment, the results from the simulation show good agreement with the measured data. The results showed that, using up to 20% of rubber as fine aggregate with the addition of 3% NS can produce a higher compressive strength than the NC. Experimental results of this research indicate that incorporating nano silica into RuC mixes enhance sound absorption and thermal conductivity compared to normal concrete (NC) and rubberised concrete without nano silica. This work suggests that it is possible to design and manufacture concrete which can provide an improvement to conventional concrete in terms of the attained vibro-acoustic and thermal performance.

This practice-led research masters produced four musical compositions exploring concepts of Perspectivism, musical minimalist aesthetics and improvisation to create contrasting sonic environments in a site-specific performance space. The compositions, which combine live acoustic performance with live & pre-composed electronic performance, all adopt a particular spatial approach I call The Triadic Space Layout, in which the musicians and loudspeakers are ‘fractured’ between three rooms, creating distinct yet related sonic environments. Through an iterative process of reflective practice, two broad compositional approaches were settled upon, termed Sonic Environmental Perspectivism and Improvisational Perspectivism. This exegesis describes four final compositions that represent the culmination of this process of reflective practice, and demonstrate these compositional approaches. Compositions Lady Fanboy and Snorkel’s Dark Room sonically distinguish each room of The Triadic Space Layout through either harmonic or tonal registers of the pre-composed electronics. These compositions utilise graphic scores to guide the musicians’ performances. This approach is titled Sonic Environmental Perspectivism. SWEET SWEET and Dancing Squares utilise the musicians’ improvisations to sonically differentiate each room as they receive identical pre-composed electronic music. This compositional approach was titled Improvisational Perspectivism.

Virtually all reciprocating internal combustion engines are fitted with mufflers. The muffler fitted to an engine is intended to reduce the pressure pulses associated with the exhaust gas leaving the cylinders of the engine. Generally mufflers fitted to such engines are essentially reactive devices as opposed to being dissipative devices. The aim of this research is to develop a computational fluid dynamics (CFO) model to predict the acoustic and mean flow performance of reactive mufflers used with large diesel engines for agriculture, mining, transport and marine applications. Currently such mufflers are designed on a simplified theoretical and/or empirical basis. Consequently the design is generally conservative and so it results in weight and cost penalties. The basis of the CFD acoustic modelling approach is to apply a pulse of suitable amplitude and duration at the inlet of the muffler. The time dependent CFD model determines flow variables associated with the resulting perturbation at the outlet of the muffler. The inlet and outlet pressure time histories derived from the CFD analysis can be Fourier transformed to allow the frequency-dependent transmission loss of the muffler to be found. The acoustic pulse can also be superimposed on a steady flow at the inlet and the resulting perturbation superimposed on the steady flow at the outlet can be determined. Thus the frequency-dependent transmission loss for the acoustic with mean flow performance of the muffler can be found. This CFD modelling approach is used to predict the performance of various types of reactive mufflers and the CFD models are validated against laboratory and published results of full-scale silencers.