Alan Forster

Heriot-Watt University · School of Energy, Geoscience, Infrastructure & Society

Gradually, sustainable maintenance in the heritage buildings conservation moving forward to achieve The Sustainable Development Goals (SDGs), 2030 Agenda. The aim of this paper is to determine sustainable lime-based mortar repair in heritage buildings conservation based on calculation procedures of Green Maintenance model within cradle-to-site boun...

Heritage science is an established and thriving field of enquiry. Initially considered as inherently cross-disciplinary, encompassing both the needs of conservators and practitioners and the high-quality evidence produced by scientists, heritage science has, through its expansion in recent years, formed a discipline in its own right. Here, we exami...

This chapter considers the development of construction and engineering education that historically chartered an increasingly decoupled trajectory from being practical in nature, to include progressively more theoretical instruction. Indeed, over the last half century, construction and engineering education has become increasingly theoretical, and i...

In the absence of resources of calcitic aggregates this work aimed to confirm the suitability of Scottish aggregates in NHL mortar. Strength, sorptivity, porosity and carbonation of mortars made with one siliceous and one felsic (granitic) aggregate have been studied. The results suggest that there are no technical barriers to their use and that en...

Masonry construction is ubiquitous and is most typically employed for the construction of fundamental structural architectural elements. It is thus extremely important in architectural conservation , and visual survey, recording and documentation often start with such primary elements. Recording has, however, traditionally been a laborious manual p...

This study explored the effects of formulation modifications of natural hydraulic lime (NHL) mortars exposed to hot temperature and high humidity conditions. The modified mortars were seeded by oyster shell powder, partially replacing the sand. The mortar samples underwent a curing period of 56 days with five observation days. The pH, carbonation d...

Natural hydraulic lime (NHL) is considered to be more environmentally friendly than Portland cement (PC) since it has a lower calcination temperature and the ability of carbon dioxide (CO2) sequestration during the hardening process. Both factors contribute to the fact that NHL has higher environmental credentials. Both of these characteristics con...

To equip graduates to respond to sustainability challenges, higher education institutions are developing programs and innovative pedagogical approaches that target new types of 21st century knowledge and skills. Resilience is a core concept in sustainability discourse, and one that is also driving pedagogical innovation that targets specific learne...

Masonry structures constitute a significant proportion of the international traditional, and historic built environment. In Scotland alone, there are 500,000 pre-1919 traditional buildings mainly masonry-built, and more than two-thirds of the 300 properties currently in the care of Historic Environment Scotland (HES) are masonry-built. Traditiona...

Purpose The spirits industry is a major economic contributor worldwide, often requiring years of maturation in barrels that is associated with significant release of ethanol into the surrounding environment. This provides carbon nutrition for colonisation of black fungal growths, one type being Baudoinia compniacensis , or Whisky Black. Although gr...

Traditional visual fabric surveying has been shown to lack accuracy and objectivity, and be characterised by limited interoperability, with other methods significantly reducing productivity and hindering efficiency. Moving beyond established visual survey methods, the rapid evolution of reality capture technologies used for digital documentation, s...

Two ongoing and recurrent debates in the employment of academic staff are (1) how much industry experience should faculty staff have? and (2) what priority is given to research, teaching or both? Such debates take place worldwide and are particularly relevant to vocational subject areas. Through a statistical analysis of circa 200 job adverts for l...

Since the Middle Ages advances in manufacture and chemical processes have improved standards of window glass production. This can be identified through decreasing levels of visible imperfections in window glass made ostensibly, prior to the 1950s. The importance of retaining historic window glass cannot be under-stated with the inherently imbued cu...

Lime binders are utilised worldwide and are associated with a considerable scale of production and corresponding CO2 emissions. The relevance of this review is therefore international in scope, with production transcending geographical boundaries and construction practices. An holistic view of lime binders, considering their provenance, production...

Methods employed for surveying buildings for condition have traditionally been reliant upon visual assessment and manual recording. Survey of traditional masonry also ostensibly conforms to this approach but, due to the sheer volume of masonry units composing walls, it is often prohibitively time consuming, exceptionally complex and ultimately cost...

The widespread adoption of alternative binders are playing an increasing role in carbon dioxide (CO2) abatement in green construction and the repair of traditionally built structures. Natural Hydraulic Lime (NHL) has better environmental credentials than Portland Cement (PC) due in part to its lower calcination temperature and its ability to absorb...

Changing climatic conditions are contributing to faster deterioration of building fabric. Increasing number of heavy rainfall events can particularly affect historic and Cultural Heritage (CH) buildings. These evolving and uncertain circumstances demand more frequent survey of building fabric to ensure satisfactory repair and maintenance. However,...

In this conceptual paper, we illuminate Western building conservation philosophy practice with insights into Eastern conservation philosophy and associated aesthetic understanding. We frame dialogue recognising individual and societal perspectives on treatments to buildings that attempt to attain ‘permanence’ or ‘impermanence’ in form, fabric, and...

Despite the rapid development of reality capture technologies and progress in data processing techniques, current visual strategies for defect surveying are time consuming manual procedures. These methods often deliver subjective and inaccurate outcomes, leading to inconsistent conclusions for defect classification and ultimately repair needs. In t...

Thirty shards of medieval window glass from Elgin Cathedral in northeast Scotland have been subjected to compositional analysis by portable X-ray fluorescence and scanning electron microscopy-energy-dispersive X-ray spectroscopy. Comparison with previous analytical studies suggests that the majority of the glass was probably produced in France, whi...

Glass waste and crucible fragments from the late 17th – early 18th century Scottish glass furnace at Morison's Haven, East Lothian was characterized using a range of analytical techniques (SEM-EDX, p-XRF, LA-ICP-MS and micro-XRF). Morison's Haven is the earliest excavated glass furnace in Scotland. The glass working waste provides a unique opportun...

From the mid-20th C., construction and engineering pedagogy and curricula have moved from long-held traditional experiential apprenticeship approaches to one ostensibly decoupling practice and theory. This paper traces this decoupling and explores modern-day opportunities and challenges for recoupling university education with industry practice. Wi...

An opinion piece that argues for a more balanced portfolio of academic staff within faculty, whereby pracademics are ‘pivotal’ academic staff who can ‘talk the talk and walk the walk’ with students who have industrial placement experience.

‘Career Academics’ are principally research-led, entering academia with limited or no industrial or practical experience. UK Higher Education Institutions welcome them for their potential to attain research grant funding and publish world-leading journal papers, ultimately enhancing institutional reputation. This polemical paper problematises the C...

Indigenous natural Scottish aggregates are currently underutilised for conservation mortars when set within a context of total volume of aggregate extraction. Their geological variability is considerable but they can be broadly characterised by region and predominantly include granitic and siliceous forms. These materials have been associated with...

The maintenance of the external fabric of historic buildings constitutes a large portion of overall building life cycle costs.Advanced reality capture and data processing technologies have the potential to transform existing survey practice,providing surveyors with objective data pertaining to building fabric, in a more rapid (frequent), safe and c...

Delivering excellence in higher engineering education is dependent on many variables. This includes programme design, delivery and content, university support and the knowledge, experience and enthusiasm of faculty members. Over the past decade there has been a notable shift in engineering faculty recruitment policy. No longer is the professional a...

Internationally, historic masonry buildings constitute a significant proportion of the traditional built environment. In the UK alone, there are 450,000 listed buildings and 10.6 million pre-1945 structures, a high proportion of which have been constructed in traditional masonry. The value of the historic built environment is significant and as suc...

Purpose – Sustainability is well understood to encapsulate economic, environmental and societal parameters. The efficiency of maintenance interventions for historic buildings is no exception and also conforms to these broad factors. Recently, environmental considerations for masonry repair have become increasingly important and this work supports t...

Ammonium nitrate leachant was used to accelerate the deterioration of mortars containing natural hydraulic lime binders. Loss of binder reduced the alkalinity and strength of the mortar and increased its sorptivity. The leached depth followed diffusion-controlled kinetics with the rate constant increasing in line with the increasing free calcium hy...

Construction education is context-laden, navigating and reflecting the byzantine influences of period, place and person. Despite considerable rhetoric, in UK higher education and construction studies in particular the importance of contextualized teaching is being devalued. Over the past decade a growing number of new teaching staff to university l...

Purpose – The purpose of this paper is to evaluate the risks of building defects associated with rapid advancement of “green” construction technologies. It identifies the methods adopted by the sector for the determination of pre-construction defects that are framed within the context of, traditional; scientific; and professional design approaches....

Window glass at Newhailes, a neo-Palladian villa located in Musselburgh, near Edinburgh, Scotland, was analysed using portable x-ray fluorescence (pXRF) spectroscopy. The elemental compositions of 512 panes of glass were collected and analysed. Twelve glass types were observed, falling into two main groups: plant-ash fluxed glass which can be dated...

Commercially-produced ‘restoration mortars’ are increasingly being used in stone masonry conservation. The convenient ‘mix and go’ approach of these materials is opening up the area of masonry repair to a wider, lesser skilled, consumer base. Pragmatic site practice with restoration mortars often leads to the modification of materials with the aim...

Masonry using lime binders is very common in all regions of the world. Models for the future climate in northern regions suggest more intense rainfall which will result in the materials used in mass masonry being saturated for longer periods and therefore at higher risk of binder leaching and consequent deterioration. In this first study of lime bi...

Purpose – Deterioration in natural stone is associated with many decay mechanisms and often the inherent composition of the materials themselves. Sandstone varies considerably but they all require a cementing matrix to bind amongst others, the silica (SiO 2 ) particles together (Reading, 1989). In calcareous sandstones and limestones this binding m...

The perceived increasing use of ‘restoration mortars’ for repair of historic masonry is often viewed as controversial due to the long-standing contention associated with ‘plastic’ repairs in the heritage sector. Almost innumerable traditionally built sandstone structures exist worldwide and the wide scale use of restoration mortars for their repair...

The use of restoration mortars for stone repair on historic masonry buildings and structures is becoming increasingly more prominent in Scotland; the negative impacts of climate change on the built heritage combined with the current financial constraints imposed on many construction projects, may be playing a role in the apparent increase in ‘plast...

Masonry built in lime mortar is one of the principle building materials used in traditional construction. This form of construction can convey the appearance of strength and stability and could be argued to epitomise built homogeneity. This may however not reflect reality due to deterioration of the wall core resulting in an alteration in the effec...

Purpose – The purpose of this paper is to address the issue of perceptions of suitability of different materials for a repair. The use of highly cementitious materials in the repair of historic masonry is causing great concern due to their incompatibility with adjacent stone and the associated accelerated deterioration which results from their use....

Many examples of historic graffiti have been shown to be worthy of attention and conservation. The examples discussed in this article have been selected for their previous academic study, enabling rational assessment. This work does not suggest that only those examples of historic graffiti that have been subject to academic investigation can be eva...

Purpose Graffiti, both ancient and contemporary, could be argued to be significant and therefore worthy of protection. Attaching value is, however, subjective with no specific method being solely utilised for evaluating these items. The purpose of this paper to help those who are attempting to evaluate the merit of graffiti to do so, by determining...

It would be assumed that a survey of a masonry structure would result in the production of an objective report. This situation cannot necessarily be guaranteed as the experience and understanding of masonry deteriorology and repair will vary from practitioner to practitioner. The difference in reporting will clearly determine alterative starting po...

Purpose – The selection of lime mortars for masonry structures can be an important component of a repair or new build project. This selection is considered difficult due to the number of variables to consider during the decision‐making process and the perceived inherent complexity of the materials. The purpose of this paper is to discuss the select...

Maintenance is essential for long-term performance of any building. It enables the simultaneous retention of value in a structure and contributes to a country's gross domestic product. The efficacy of maintenance interventions for historic buildings can be assessed based on cost, conformity to building conservation philosophy and, increasingly, env...

Purpose – The assessment of a deteriorating masonry structure should lead to an objective evaluation of condition. This process is, however, inevitably subjective owing to human interpretation. The condition of the substrate and the required repairs cannot be guaranteed and may vary from building inspector to inspector. For conservation works the d...

Abstract: It would be assumed that a survey of a masonry structure would result in the production of an objective report. This situation cannot necessarily be guaranteed as the experience and understanding of masonry deteriorology and repair will vary from practitioner to practitioner. The difference in reporting will clearly determine alterative s...

Purpose – The techniques available for the repair of historic masonry structures are extremely wide ranging. The advantages and disadvantages of each type of repair can be evaluated in terms of cost, time and quality as with modern projects. It is however, important to realise that when repairs to historic buildings are selected they must conform t...

Purpose The techniques available for the repair of historic masonry structures are extremely wide ranging. The advantages and disadvantages of each type of repair can be evaluated in terms of cost, time and quality as with modern projects. It is however, important to realise that when repairs to historic buildings are selected they must conform to...

Purpose – It is well understood that maintenance is critical to the survival and in‐service use of any building. Despite recognition that the best way of protecting and maintaining historic buildings is to undertake a combination of proactive and reactive maintenance, it is rarely adopted or implemented, and when it is undertaken it often results i...

Earth building is a sustainable method of construction that has been used in Scotland and worldwide for many centuries. Earth construction can be subdivided into various forms, with cob being one of the most frequently occurring types utilised within the UK. This paper presents an investigation of a case study of a historical building in Scotland....

Purpose The influence of flood conditions upon traditional cob construction is little understood. This paper aims to investigate the ability of cob materials to resist flood situations and documents basic failure mechanisms. This work also seeks to investigate the wettability characteristics of cob materials utilising environmental scanning electro...

Purpose The purpose of this research is to highlight issues relating to binder migration in traditional lime mortars and the potential consequences of this phenomenon. The paper focuses on traditional mass masonry construction and will be of special interest to those surveying, maintaining and repairing historic ruinous structures and heavily expos...

The use of lime-based materials and the characteristics of lime mortars