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The multi-scale numerical simulation method, able to represent the complexity of the random structures and capture phase degradation, is an effective way to investigate the long-term behavior of concrete in service and bridges the gap between research on the material and on the structural level. However, the combined chemical-physical deterioration mechanisms of concrete remain a challenging task. The purpose of this paper is to investigate the degradation mechanism of concrete at the waterline in cold regions induced by combined calcium leaching and frost damage.

With the help of the NIST’s three-dimensional (3D) hydration model and the random aggregate model, realistic 3D representative volume elements (RVEs) of concrete at the micro-, the meso-, and the macro-scales can be reconstructed. The boundary problem method is introduced to compute the homogenized mechanical properties for both sound and damaged RVEs. According to the damage characteristics, the staggering method including a random dissolution model and a thermo-mechanical coupling model is developed to simulate the synergy deterioration effects of interacted calcium leaching and frost attacks. The coupled damage procedure for the frost damage process is based on the hydraulic pressure theory and the ice lens growth theory considering the relationship between the frozen temperature and the radius of the capillary pore. Finally, regarding calcium leaching as the leading role in actual engineering, the numerical methodology for combined leaching and frost damage on concrete property is proposed using a successive multi-scale method.

On the basis of available experimental data, this methodology is employed to explore the deterioration process. The results agree with the experimental ones to some extent, chemical leaching leads to the nucleation of some micro-cracks (i.e. damage), and consequently, to the decrease of the frost resistance.

It is demonstrated that the multi-scale numerical methodology can capture potential aging and deterioration evolution processes, and can give an insight into the macroscopic property degradation of concrete under long-term aggressive conditions.

This paper offers a personal insight from a care professional into attitudes to the ageing process and being old.

The paper is an invited opinion piece and comment based on the author's experiences in dealing with the ageing and physical deterioration of close family members. It is an autobiographical reflection upon stereotypical views of ageing and how they might change.

The degree of negativity of the perspective on ageing depends both on the “closeness” of the familial relationship, the demands thereby made on the individual and the chronicity of the physical deterioration of the ageing family member. Attitudes might change as a result of an ageing population that might become healthier than previous pensioned populations.

Personal insights from experienced care professionals who still struggle with the emotional costs of the ageing of a relative can help the understanding of others who are dealing with similar situations. Even professionals face difficulties in confronting the ageing of loved ones and the practical issues involved with their care.

The purpose of this paper was exploring and comparing different deterioration models based on statistical and machine learning approaches. These models were chosen from their successful results in other case studies. The deterioration models were developing considering two scenarios: (i) only the age as covariate (Scenario 1); and (ii) the age together with other available sewer characteristics as covariates (Scenario 2). Both were evaluated to achieve two different management objectives related to the prediction of the critical condition of sewers: at the network and the sewer levels.

Six statistical and machine learning methods [logistic regression (LR), random forest (RF), multinomial logistic regression, ordinal logistic regression, linear discriminant analysis and support vector machine] were explored considering two kinds of predictor variables (independent variables in the model). The main propose of these models was predicting the structural condition at network and pipe level evaluated from deviation analysis and performance curve techniques. Further, the deterioration models were exploring for two case studies: the sewer systems of Bogota and Medellin. These case studies were considered because of both counts with their own assessment standards and low inspection rate.

The results indicate that LR models for both case studies show higher prediction capacity under Scenario 1 (considering only the age) for the management objective related to the network, such as annual budget plans; and RF shows the highest success percentage of sewers in critical condition (sewer level) considering Scenario 2 for both case studies.

There is not a deterioration method whose predictions are adaptable for achieving different management objectives; it is important to explore different approaches to find which one could support a sewer asset management objective for a specific case study.

The originality of this paper consists of there is not a paper in which the prediction of several statistical and machine learning-based deterioration models has been compared for case studies with different local assessment standard. The above to find which is adaptable for each one and which model is adaptable for each management objective.

The purpose of this paper is to review the evolution of inspection and maintenance (I&M) practices used for aging and newly built oil and gas (O&G) facilities. It also proposes a framework and an approach for mechanizing inspection planning to perform preventive maintenance (PM) activities, taking technical condition (TC) and relative degradation (RD) into consideration.

The paper systematically collects, categorizes, and analyzes the published literature of both researchers and practitioners. It also utilizes industrial experience that has been accrued and utilized from inspection planning practices for static mechanical equipment on aging O&G production plants.

The paper defines significant issues in I&M of O&G assets related to: different philosophies; stakeholders’ requirements trade-off; dependability and asset deterioration challenges; items interacting with inspection planning mechanization processes and I&M optimization approaches. A framework is identified to mechanize the inspection planning process in order to reduce the effect arising from human involvement, while improving the effective utilization of data from different sources. The suggested approach improves the quality of an inspection program, while minimizing the variability and cost to the engineering contractors as well as to the owners of O&G facilities.

The mechanization of inspection planning (MIP) is vital to have inspection programs with uniform quality. The currently employed inspection practices face challenges in maintaining uniform quality from one inspection program to another due to the variability present in the planning process, especially among the different inspection planning engineers. The suggested fuzzy logic-based MIP supports the minimization of the variability and increases the quality of inspection programs.

The paper provides a comprehensive review of research contributions and industrial development efforts. These will be useful to the life cycle stakeholders in both academia and industry in understanding the inspection planning problem and solution space within the O&G asset I&M context.

This article aims to analyze strategically optimal maintenance actions for a multi‐component system whose deterioration is observed through a monitoring system set in place to support condition‐based maintenance.

Deterioration of a multi‐component system is modeled by a continuous‐time jump diffusion model which incorporates interaction between the components of the system. A simulation‐based optimization heuristic is developed to obtain strategically optimum maintenance actions. The methodology is applied to an illustrative example.

The article finds that the framework facilitates analyzing at a strategic level the role of degree of response to the deterioration of components for the overall functionality of a multi‐component system. The optimal solution for the illustrative example recommends a provider to perform a variety of opportunistic maintenance.

In this article, a framework is developed to determine strategically optimal maintenance actions for a multi‐component system whose deterioration is observed in real‐time through embedded monitoring units set in place to support condition‐based maintenance (CBM). The framework facilitates analyzing at a strategic level the role of degree of response to the deterioration of components for the overall functionality of a multi‐component system. A strategically optimal maintenance policy can then be enhanced to develop a detailed tactical maintenance strategy. This approach is expected to benefit the management of long‐term service agreements, where a service contract is sold bundled with a product, which makes a provider responsible for maintaining the product over a specified contract period.

Besides a tactical approach for performing maintenance, in order to stay profitable in the long‐run, a decision maker needs to assess the strategic performance of maintenance strategies adopted. This framework is a first attempt to facilitate this analysis at a strategic level for a monitoring‐enabled multi‐component system.

This paper aims to review the current state of building decay in Hong Kong, and attempts to identify and analyze the perceived benefits of implementing the Mandatory Building Inspection Scheme (MBIS) via an industry-wide empirical questionnaire survey.

A total of 340 professional respondents who have gained hands-on experience in either new building works or building management or building repair/maintenance were requested to complete a survey questionnaire to indicate the relative importance of those benefits identified in relation to MBIS. The perceived benefits were measured, ranked and compared according to the different roles of industrial practitioners, and between the residents in private premises and those in public estates.

The survey findings suggested the most significant benefits derived from implementing MBIS to be: raise the overall building safety toward residents and the general public; create more job openings and business opportunities in building repair and maintenance services; and MBIS is an effective solution to address the problems with building decay (e.g. dilapidation and control over the existing unauthorized building works). The results of factor analysis indicated that the 13 perceived benefits of implementing MBIS were consolidated under three underlying factors: addressing building dilapidation and assuring building safety; improving the living environment and upgrading property values; and creating more job openings and business opportunities.

As MBIS was officially launched on June 30, 2012, it is expected to be one of the proposed effective measures in resolving the long-standing problems of building neglect and deterioration in Hong Kong and overseas, especially to those existing old private premises.

In the long run, the number of prematurely ageing buildings would be reduced, and the service life span of existing private premises would be prolonged. This is in line with the sustainability principle of providing a better living and the working environment within the community as a whole.

This paper aims to find a suitable solution to treat the solidification paper by using hydroxypropyl cellulose (HPC) to improve the mechanical, physical and chemical properties of paper.

The samples have gone several stages, starting with the manufacture of paper from the linen pulp and the same components of the hardened manuscript papers. It was subjected to artificial aging to reach an age comparable to the manuscript age, then it was subjected to natural aging by inoculation it with A. niger. Mechanical cleaning of the leaves was done with soft brushes. The samples have been consolidated by HPC 2%. Digital microscopy, scanning electron microscopy, mechanical properties measurement, color change, Fourier transform infrared and pH measurements were used to assess the effect of HPC on the qualities of leaves.

HPC succussed in strengthening and restoring the natural, chemical and mechanical properties for the solidified leaves.

The solidified papers phenomenon constitutes severe suffering for manuscripts and books conservators. The paper consolidation initial stage is one of the most important conservation stages because paper has lost many natural, mechanical and chemical properties. The most important feature of this study is providing a solution to the hardened leaves strengthening problem and restoring their chemical, natural and mechanical properties.

The purpose of this paper is to provide a concise overview of the problem of building decay in Hong Kong, the current government measures concerning dilapidated buildings and the latest development and implementation of the mandatory building inspection scheme (MBIS). A comparison of various MBISs from other jurisdictions of the world is also given.

A desktop study of building inspection procedures, repair and maintenance policies was carried out, followed by an industry-wide opinion survey conducted by means of self-administered questionnaires. Target respondents are within the construction community of Hong Kong. The perceived benefits, potential difficulties and insightful recommendations or good practices are investigated. A comparison of the relative ranking of individual mean scores from various groups of respondents is presented in this paper.

The execution of MBIS was found to be effective in enhancing public awareness of the importance of building upkeep and recognition of the property owner's legal responsibilities in this respect. Private property owners were made aware of the necessity to take holistic preventive measures to maintain the overall safety of their own buildings. A comparison of MBIS with other similar MBISs across different cities, revealed similarities as regards the inspection cycle, scope of inspection and qualifications of inspectors. The main difference related to the age rather than the height of target buildings.

Proper inspection and maintenance is necessary to keep buildings in good condition to avoid injury or loss of life due to sudden collapse of structures or their elements such as concrete spalling and fall of window frames. The official launch of MBIS on 30 June 2012 is one of the proposed effective measures to resolve the long-standing problems of building neglect and deterioration in Hong Kong with particular regard to the existing old private premises.

The execution of MBIS should be useful in improving the safety and health status of the dilapidated premises and in so doing safeguarding the residents and general public. To further identify the perceived benefits and potential difficulties of MBIS, and to suggest insightful recommendations or good practices for its successful future implementation, an opinion survey was launched among construction practitioners in Hong Kong between March and April of 2012.

This paper extends the authors’ previous research work investigating resilience for municipal infrastructure from an asset management perspective. Therefore, this paper aims to formulate a pavement resilience index while incorporating asset management and the associated resilience indicators from the authors’ previous research work.

This paper introduces a set of holistic-based key indicators that reflect municipal infrastructure resiliency. Thenceforth, the indicators were integrated using the weighted sum mean method to form the proposed resilience index. Resilience indicators weights were determined using principal components analysis (PCA) via IBM SPSS®. The developed framework for the PCA was built based on an optimization model output to generate the required weights for the desired resilience index. The output optimization data were adjusted using the standardization method before performing PCA.

This paper offers a mathematical approach to generating a resilience index for municipal infrastructure. The statistical tests conducted throughout the study showed a high significance level. Therefore, using PCA was proper for the resilience indicators data. The proposed framework is beneficial for asset management experts, where introducing the proposed index will provide ease of use to decision-makers regarding pavement network maintenance planning.

The resilience indicators used need to be updated beyond what is mentioned in this paper to include asset redundancy and structural asset capacity. Using clustering as a validation tool is an excellent opportunity for other researchers to examine the resilience index for each pavement corridor individually pertaining to the resulting clusters.

This paper provides a unique example of integrating resilience and asset management concepts and serves as a vital step toward a comprehensive integration approach between the two concepts. The used PCA framework offers dynamic resilience indicators weights and, therefore, a dynamic resilience index. Resiliency is a dynamic feature for infrastructure systems. It differs during their life cycle with the change in maintenance and rehabilitation plans, systems retrofit and the occurring disruptive events throughout their life cycle. Therefore, the PCA technique was the preferred method used where it is data-based oriented and eliminates the subjectivity while driving indicators weights.

The purpose of this paper is to explore the wellbeing benefits and challenges that arise in dance-theatre performance making with older people. It also addresses the notion of taking artistic risks when making community art.

This study draws on current research into older people's participatory performance and the impact it has on wellbeing, in relation to a practice as research dance-theatre project: Body of Knowledge in 2012. The analysis draws on primary experiential and secondary data to describe the possible physical, mental, social and emotional benefits of taking part in performance projects, as well as identifying the challenges and criticisms related to this kind of work.

The physical and mental impacts of participating in dance activity are well documented, but there are also valuable social and emotional effects which are hard to quantify, yet just as valuable. Evidence collected from other projects along with my own research, suggests that along with health benefits, the shared endeavour of taking part in a performance project can help an older person to build confidence, social networks, a sense of purpose and refresh or learn new skills. By encouraging older performance groups to show their work to audiences of mixed ages, it is also possible to challenge ageist perceptions.

This paper draws together current research on the physical, mental, social and emotional value of participatory dance-theatre performance work, in relation to practical findings from a specific project.