Natural fibre composites have recently attracted a great deal of attention by the marine industry due to their many attractive benefits for structural applications. Beneficial properties include; high strength-to-weight ratio, sustainable characteristics and low cost. These materials unfortunately are highly susceptible to moisture ingress which can lead to inferior thermo-mechanical properties and structural failure. These failure routes may be diverse and difficult to detect therefore adequate material selection, processing, and testing is paramount in achieving a long lasting functional marine structure. This chapter focuses on the investigation of these imparted moisture related attributes and their influence on properties.

Silver nanoparticulate enhanced aqueous silane/siloxane emulsions and their efficacy against biofouling mechanisms are presented within this study. Different concentrations of silver nanoparticulates were added into viscous shear-thinning aqueous treatments and key attributes required for facade remedial applications assessed. Water repellence, biofouling resistance, and aesthetical alteration were studied to assess key treatment attributes. In addition, assessment of the porosity, sorptivity, and treatment depth was used to identify penetration and facade protection efficacy and morphological alteration of the masonry substrate. Results showed that silver nanoparticulate incorporation did not impede treatment penetration, better water repellent attributes were achieved with increased concentration while effectively conserving the morphology and aesthetics of the substrate. It was concluded that the reduced bioreceptivity observed primarily stemmed from the silver nanoparticulates ability to sanitise the surface, and that only small concentrations (<0.5%wt) were required to attain significantly beneficial improvements. Treatments were deemed practically and commercially viable for retrofit and heritage projects.

Uni-directional (UD) and cross-ply (CP) cellulosic flax fibre epoxy composites were produced by hybridising UD carbon fibre prepreg onto flax system. A compression moulding technique was used to produce both flax and carbon/flax hybridised laminates. The effect of carbon fibre hybridisation on the water absorption behaviour, thermal and mechanical properties of both UD and CP flax specimens were investigated by means of water absorption, tensile, thermogravemetric analysis and flexural testing. The results showed that water absorption behaviour of hybrid samples are markedly improved compared to those without hybridisation. Similarly, the thermal stability, tensile and flexural properties of the hybrid composites are significantly improved in comparison with UD and CP flax composites without hybridisation. The experimental results suggest that cellulosic flax fibre reinforcement contributed to improve the toughness properties by promoting crack propagation whereas the carbon fibre contributed in improving thermal stability, water absorption behaviour and the overall strength and the stiffness of the hybrid composites.

In this study the influence of metal oxide nanoparticulates on aqueous silane/siloxane pore lining facade remediation treatments is presented. Pre-treatment attributes including stability and rheological properties were investigated. Colloidal titanium dioxide and zinc oxide nanoparticulates were incorporated into the novel silane/siloxane o/w emulsions and characteristics of such systems were then assessed in terms of thermal stability and rheological modification. Post-treatment attributes including water repellence, sorptivity and aesthetical alteration were also assessed. Enhanced emulsion properties were found to be dependent upon the extent of aggregation which was attributed to the morphology and size of the particulates. Excess of colloidal medium did reduce viscosity, however a significant stabilization was achieved regardless. Post-treatment results showed that a improved water repellence could be achieved with negligible visible alteration to substrate aesthetics; a novel benefit of such treatments for retrofit and remediation products combined with zero VOC emissions, complying to new EU directives. Findings undoubtedly confirm the potential for nanoparticulates to be used as effective emulsifiers in similar emulsion systems while being commercially and practically viable for facade remediation due to the small concentrations required. (C) 2013 Elsevier Ltd. All rights reserved.

This paper presents the evaluation of zinc and titanium nano-oxide silane/siloxane emulsions and their resistance to biofouling by algal colonisation. A culture streaming study was conducted to evaluate each treatment using mortar samples. Characterisation of the treatments included assessment of the porosity, surface roughness, sorptivity, hydrophobicity, treatment depth and visual alteration. The results showed that nanoparticulate incorporation did not adversely alter treatment penetration. Nanoparticulate treatments improved water repellence significantly while effectively conserving the morphology of the substrate. Treatments had negligible impact on visual aesthetics of the substrate making them ideal for future retrofit and heritage schemes. It was concluded that the reduced bioreceptivity observed primarily stemmed from the nanoparticulates ability to photocatalytically breakdown contaminants.

To replace conventional toxic variants, hydroxyl terminated polydimethylsiloxane (PDMS) with different viscosities and concentrations were incorporated into aqueous emulsions. Physical stability and thermal stability was assessed through centrifugation and thermal conditioning respectively. Relevant rheological properties were used to help further understand stability mechanisms. The colour, gloss, water contact angle and treatment depth were also assessed to characterise imparted performance to terracotta roofing tiles. Improved water repellence with concentration and chain-length respectively was achieved. The treatment depth and stability results showed that a silane/siloxane balance was required for optimisation. Emulsions did not alter the visual aesthetics of the substrate significantly.

Fundamental issues associated with addressing the UK housing shortage problem are climate change and the lack of usable building space. Conservation of old buildings, maintaining green land and a country filled with single walled older properties mean that the UK government has to retrofit existing older building stock. This would make a significant impact on reducing the carbon footprint of each household as well as to alleviate energy supply problems. The investigation of novel zinc oxide and titanium dioxide nanoparticulates in aqueous silane/siloxane oil-in-water (O/W) emulsions for practical exterior facade applications is presented. An initial emulsion was developed and optimised before further improvement through nanoparticulate incorporation was achieved. Nanoparticulates of zinc oxide and titanium dioxide were dispersed respectively using ultrasonication in n-isooctyltriethoxysilane before being incorporated into a base emulsion. Once formulations were optimised, applied studies and fundamental assessment of these emulsions were conducted. The aim of the work presented was to produce a practical facade emulsion that could be used in the retrofitting of existing building stock or for heritage remedial treatments. Initial research indicated that water was the governing factor in a diverse range of facade degradation mechanisms; improving water repellence, thermal envelope efficiency while reducing biofouling was recognised as being of key interest in this field. The study gives insight into aqueous water repellent emulsions, nanoparticulate integration by commercially practical means, and assessment of the attributes exhibited by such treatments. Rheological and morphological characterisation concluded that a gelled network structure is produced by the incorporation of the fabricated nanoparticulate colloids. The emulsions retained shear-thinning characteristics, ideal for deep treatment penetration to be achieved for porous silicate substrates. Accelerated ageing tests showed that the nanoparticulate emulsions were substantially more thermodynamically stable than the emulsion control while also being physically more stable due to surfactant-particulate stabilisation mechanisms of the polar phases. From further investigation it was also found that hydroxyl terminated siloxane could be integrated into these emulsions, helping to improve the ‘green credentials’ of such systems through the replacement of conventionally used trimethoxy terminated siloxanes, that release harmful methanol upon curing, thus substitution is preferential and in line with current European policy. Treatments improved thermal envelope efficiency of structures through the reduction of retained water in various forms including rising damp. Assessment was carried out using model houses exposed to various temperature and humidity scenarios under controlled heating. The findings showed that water was the root cause of heat loss and thus a key parameter when considering the improvement of a structures’ carbon footprint. These treatments allow water vapour to permeate out of a structure passively, reducing internal humidity issues including microbiological degradation and health related problems experienced by occupants. Investigation of bioreceptivity conducted though an 8 week algal culture streaming study concluded that treatments with <0.1wt% of the aforementioned nanoparticulates could reduce biofouling through photo-induced sanitisation. Furthermore, it was also found that while water repellence may vary at the facade interface due to the respective metal oxides photocatalytic nature, substrate interior water contact angles should remain high due to the absence of UV light. This is of key importance as it implies that simultaneous antifouling and rising damp remediation may be achieved by such treatments. One of the major advantages of the treatments presented is that they do not effectively alter the aesthetics of the substrate, unlike photo-induced ‘self-cleaning’ coatings that turn the facade white. In addition, these treatments are not susceptible to problems related to the cracking or chipping of coated surfaces, allowing them to provide better protection. From the above points it is clear that these treatments are the next paradigm in facade protection, complying with current social, ecological, political and industrial needs. This study presents the inception, development and investigation of key attributes and mechanisms of these novel treatments while showing critically that such emulsion treatments are practical with great potential to enhance the lives of UK residents.

This paper presents the evaluation of titanium dioxide and zinc oxide nano-particulate aqueous facade emulsions for water repellent and thermal insulation applications. Treated bricks were assessed by; thermal conductivity, water contact angle (WCA), water vapour permeation, water absorption and treatment depth measurements. In addition, a theoretical model was produced which was used to evaluate possible financial and energy saving potential of such treatments. Nano-particulate emulsions showed a 5% water beading improvement over the emulsion control. Thermal insulation of the treated samples improved significantly in wet conditions and was attributed to reduced water ingress. The titanium dioxide treatment showed approximately 45% lower sorptivity values compared to the emulsion control. Each emulsion achieved 13–14mm treatment penetration while still allowing water vapour permeation to occur. Theoretical modelling showed that all emulsions reduced energy consumption considerably allowing real financial savings to be made. Nano-particulate emulsions improved saving potential against the emulsion control by approximately 32%.

In this study a novel zinc oxide nano-particulate water repellent emulsion was applied to brick and mortar samples. The treatment used was an aqueous silane/siloxane hybrid emulsion designed to penetrate deep into a substrate. Possible water repellence and thermal insulation for household energy saving was investigated. Tests on brick and mortar assessed; porosity, treatment depth, surface energy, water contact angle, thermal conductivity and visual aesthetics. In addition, two model houses were built with one treated with the emulsion. A heating and monitoring regime was developed to quantitatively evaluate heating energy consumption in different conditions. It was found that the treatment imparted significant water repellence and enhanced thermal insulation to treated samples. The results from contact angle and surface energy measurements showed that the substrates became highly hydrophobic. Experimental results from the model houses showed approximately 5% heating energy reduction in dry conditions and approximately 20% in wet conditions. In addition, the internal humidity was reduced across various temperature scenarios. Negligible aesthetical alteration of substrates and ease of application additionally prove that significant contribution can be made by similar treatments in future nationwide retrofit projects.

Thermal properties of five screed specimens were evaluated by four different thermal analysis methods. Thermal conductivity results showed that samples with recycled glass aggregate had a substantially lower thermal conductivity compared with those of sand screeds. Variation of heat capacity between the glass and sand screed mixtures increased with elevated temperature to a significant extent; the glass screeds seemed to show the highest heat capacities at these increased levels. The 100% glass aggregate specimens exhibited a lower thermal expansion at higher temperatures showing a higher dimensional stability. From the results a model was created to assess some realistic scenarios which the screeds may be presented with. A comparison of the screeds over different temperature ranges was produced. Glass screeds were shown to save approximately three times the energy of conventional sand counterparts due to good thermal insulation. When compared, the 100% glass with rapid cementations provided the best possibility for financial savings. The study demonstrated that glass aggregate screeds could be used as a cost effective and environmentally friendly building material that superseded sand alternatives dramatically in thermal retention.

Mortar samples were obtained from a variety of dwellings in the UK with the majority from houses with rising damp. This paper aims to evaluate the mortar attributes and their influence on rising damp. The samples were characterised in the laboratory in terms of pH value and water absorption characteristics and examined using scanning electron microscopy to reveal the microstructure. It was found that the water absorption characteristics varied considerably, with older mortars having a higher sorptivity and higher concentration of soluble salts. The majority of building mortars treated for rising damp in this survey were approximately 100years old and had a typical pH value of 9. A good understanding of the relationship between rising damp and mortar characteristics was developed, which may be practically employed to assess and mitigate rising damp problems.

A novel polymer cream was applied to brick and mortar in an attempt to reduce water absorption and to improve thermal insulation for household heating energy saving. Tests were carried out on surface energy, water contact angle, thermal conductivity and sorptivity of brick and mortar with and without cream treatment. A model house was built and a heating and monitoring system was developed to quantitatively evaluate the heating energy consumption in different conditions before and after cream treatment. It was found out that cream treatment can successfully impart good water repellence and enhanced the thermal insulation of the brick and mortar. The results from contact angle and surface energy measurements showed that the materials became highly hydrophobic. Experimental results from the model house showed approximately 9% heating energy consumption reduction in dry conditions and approximately 50% in wet conditions. In addition, the internal humidity typically was reduced to almost 1/3 of that of the control. It has been demonstrated that the novel cream treatment on masonry buildings can help reduce damp problems and save household heating energy consumption which can make a significant contribution to addressing social, environmental, ecological and economic problems resulting from climate change and global warming.