Vivian Wing Yan Tam

Implementation of environmental management in the Hong Kong construction industry

The control of environmental impacts from construction has become a major issue to the public. Whilst the implementation of environmental management in construction has a direct contribution to environmental protection, it involves allocating a variety of resources for practicing various environmental management methods such as noise control, treatment of polluted water, waste recycling and reusing, and so on. The application of these methods leads to an increase in labour use, materials handling costs, which can limit their implementation. This paper provides a profile of environmental management in Hong Kong construction by identifying what contractors in Hong Kong consider to be the benefits of and barriers to the practice. The appropriateness of measures for mitigating the barrier effects is investigated. The paper provides empirical evidence of the benefits of and barriers to the process of increasing the implementation of environmental management among contractors in Hong Kong. It should help contractors to adjust their environmental management policy by efficient resources allocation within their companies.

A CHECKLIST FOR ASSESSING SUSTAINABILITY PERFORMANCE OF CONSTRUCTION PROJECTS

Construction sustainability performance is indispensable to the attainment of sustainable development. Various techniques and management skills have previously been developed to help improving sustainable performance from implementing construction projects. However, these techniques seem not being effectively implemented due to the fragmentation and poor coordination among various construction participants. There is a lack of consistency and holistic methods to help participants implementing sustainable construction practice at various stages of project realisation. This paper develops a framework of sustainability performance checklist to help understanding the major factors affecting a project sustainability performance across its life cycle. This framework enables all project parties to assess the project sustainability performance in a consistent and holistic way, thus improving the cooperation among all parties to attain satisfactory project sustainability performance.

Use of prefabrication to minimize construction waste: a case study approach

Abstract The increasing awareness of environmental impacts from construction waste has aroused much public concern. Some construction organizations have included waste management as one of the major functions of construction project management. As a result, some approaches and methods for managing construction waste have been developed. Replacing wet-trade activities with prefabrication is advocated as one of the waste minimization techniques on site. However, the adoption of prefabrication is mainly confined to public housing developments in Hong Kong. This paper uses four private building projects as case studies to demonstrate the effectiveness in the use of prefabrication to minimize construction waste in Hong Kong. The wastage levels of the four projects are compared with conventional cast in-situ methods under similar project natures and conditions. The hindrances and the future trend of adopting prefabrication in Hong Kong are also examined.

The effectiveness of Hong Kong's Construction Waste Disposal Charging Scheme

The Hong Kong Government introduced the Construction Waste Disposal Charging Scheme in December 2005 to ensure that disposal of construction and demolition (C&D) waste is properly priced to reduce such waste. The charging scheme is not only intended to provide an economic incentive for contractors and developers to reduce waste but also to encourage reuse and recycling of waste material thereby slowing down the depletion of limited landfill and public filling capacities. This paper examines the effectiveness of the charging scheme 1 year after implementation. A survey was conducted at Tseung Kwan O Area 137 and Tuen Mun Area 38, and daily C&D waste records were collected from landfills and public filling facilities between January 2006 and December 2006. The results of the survey show that waste has been reduced by approximately 60% in landfills, by approximately 23% in public fills, and by approximately 65% in total waste between 2005 and 2006. Suggestions for improving the scheme are provided.

An investigation of construction wastes: an empirical study in Shenzhen

Purpose – This paper aims to analyze on‐site production and sources of construction wastes through data obtained from a detailed questionnaire survey and structured interviews conducted in Shenzhen.Design/methodology/approach – A questionnaire survey is conducted to investigate the compositions of these construction waste and their sources. One hundred and ten copies are sent to governmental officers, designers, engineers, and contractors, and 84 responses are received, in which the respondent rate is about 76.4 percent.Findings – According to the survey results, concrete, cement, brick, timber, tile, steel, and aluminum wastes are the main waste sources produced on construction sites. The sources of these wastes are varied. Suggestions to improve the existing waste situation are also discussed.Originality/value – Various types of construction wastes are generated during construction activities. Expansion of construction wastes not only represents an enormous dissipation of resources but also results in s...

Cutting Construction Wastes by Prefabrication

Abstract Construction wastes have become the major source of solid wastes in Hong Kong. Thousands of tonnes of solid wastes are produced every year from construction and demolition activities. Increasing generation of these wastes has caused significant impacts on the environment and aroused growing public concerns. Therefore, the minimisation of construction wastes has become a pressing issue. This paper aims to: 1) reveal the status of construction wastes; 2) investigate the effectiveness of prefabrication in terms of waste reduction in replacing traditional wet-trade practices; 3) examine the factors that help minimize construction wastes by the adoption of prefabrication; and 4) explore the current waste reduction situations after adoption of prefabrication by comparing with in-situ construction. It investigates wastes generated from various wet-trade construction activities such as in-situ concreting, timber formwork, bricklaying, plastering, screeding, tiling, rebar fixing and bamboo scaffolding. Six major reasons for the excessive construction wastage are known to be: 1) cutting; 2) over ordering; 3) damaging during transportation; 4) losing during installation; 5) poor workmanship; and 6) change of design. From the findings of a structured interview survey of thirty-one construction practitioners, “timber formwork” is found to be having the greatest potential for cutting scrap, and wastes from “poor workmanship” can be greatly reduced by adopting prefabrication in construction. Furthermore, after the adoption of prefabrication, wastage generation can be greatly reduced in various wet-trade activities including concreting, rebar fixing, bricklaying, drywall, plastering, screeding and tiling. Especially in plastering, the waste reduction can be reduced by 100%. It is concluded that prefabrication of building components is one of the effective technologies of waste minimisation.

Physio-chemical reactions in recycle aggregate concrete.

Concrete waste constitutes the major proportion of construction waste at about 50% of the total waste generated. An effective way to reduce concrete waste is to reuse it as recycled aggregate (RA) for the production of recycled aggregate concrete (RAC). This paper studies the physio-chemical reactions of cement paste around aggregate for normal aggregate concrete (NAC) and RAC mixed with normal mixing approach (NMA) and two-stage mixing approach (TSMA) by differential scanning calorimetry (DSC) and scanning electron microscopy (SEM). Four kinds of physio-chemical reactions have been recorded from the concrete samples, including the dehydration of C(3)S(2)H(3), iron-substituted ettringite, dehydroxylation of CH and development of C(6)S(3)H at about 90 degrees C, 135 degrees C, 441 degrees C and 570 degrees C, respectively. From the DSC results, it is confirmed that the concrete samples with RA substitution have generated less amount of strength enhancement chemical products when compared to those without RA substitution. However, the results from the TSMA are found improving the RAC quality. The pre-mix procedure of the TSMA can effectively develop some strength enhancing chemical products including, C(3)S(2)H(3), ettringite, CH and C(6)S(3)H, which shows that RAC made from the TSMA can improve the hydration processes.

On prefabrication implementation for different project types and procurement methods in Hong Kong

Purpose – The use of prefabrication has been considered as one of the most effective waste minimization methods in the construction context; however, the industry has found difficulties to implement it. Contractors lack experience in using prefabrication and they do not know how to implement prefabrication to their projects effectively. The purpose of this paper is to present the findings of a study on the implementation of prefabrication in the context of different project types and procurement approaches.Design/methodology/approach – This paper examines possible project types and procurement methods to maximally gain benefits of using prefabricated building components. A questionnaire survey and structured interviews have been conducted.Findings – From the results, it should be noted that residential projects and design and build procurement methods are the most effective project types and procurement methods, respectively, in using prefabrication. In the interview discussion, one of the governmental em...

Environmental performance assessment: perceptions of project managers on the relationship between operational and environmental performance indicators

There is a growing concern about environmental impacts resulting from construction activities. To help minimize the environmental impacts from construction, Environmental Management Systems (EMSs) have been advocated and in some cases, implemented. Within the construction industry, Environmental Performance Assessment (EPA) forms one of the most important tools in monitoring and evaluating environmental performance. However, the relations between Environmental Operational Indicators (EOIs) (inputs) used in EPA and Environmental Performance Indicators (EPIs) (outputs) have not been tested and correlated, casting doubt on the reliability of these inputs. This paper attempts to develop a series of input (EOI) and output (EPI) indicators for EPA and measure their relations based on the perceptions of project managers. The results show that EOIs defined correlate strongly with EPIs. Therefore, EPA can help to identify areas for continuous improvement, and also provide an early indication of the environmental performance for an organization.

Managing information flows for quality improvement of projects

Purpose – A quality management system based‐ISO 9001 focuses on confirming process conformance from the initial development of a product through production, test, installation and servicing. Information management has been a key factor affecting the effective implementation of the standard. The aim of this study is to explore management of information flows in quality assurance in project management. It is hoped to that it will be helpful in pursuing continuous quality improvement in the construction industry.Design/methodology/approach – Based on the characteristics of the construction industry, this study designed an organizational structure with three levels, including firm, sub‐firms and project departments. The paper examined the difficulties for the multi‐level organizational structure in information transferring and feedback.Findings – It is found that there are information asymmetries in quality management from internal and external organizations. Internally, information asymmetry exists between c...