Emerald | Engineering, Construction and Architectural Management | Table of Contents

2nd Generation Concrete Construction: Carbon Footprint Accounting

literatinetwork@emeraldinsight.com (Frank Gerard Collins) — Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - Construction contractors and facility managers are being challenged to minimize the carbon footprint. Life cycle carbon-equivalent (CO2-e) accounting, whereby the potential emissions of greenhouse gases due to energy expenditure during construction and subsequent occupation of built infrastructure, generally ceases at the end of the service life. However, following demolition, recycling of demolition waste that becomes incorporated into 2nd generation construction is seldom considered within the management of the carbon footprint. This paper focuses on built concrete infrastructure, particularly the ability of recycled concrete to chemically react with airborne CO2, thereby significantly influencing CO2-e estimates.Design/methodology/approach - CO2-e estimates were made in accordance with the methodology outlined in the Australian National Greenhouse Accounts (NGA) Factors (Department of Climate Change, 2009) and were based on the energy expended for each life cycle activity from audited records. Offsets to the CO2-e estimates were based on the documented ability of concrete to chemically react with airborne carbon dioxide ("carbonation") and predictions of CO2 uptake by concrete and recycled concrete was made using existing predictive diffusion models. Our study focused on a built concrete bridge which was demolished and recycled at the end of the service life, and the recycled concrete was utilized towards 2nd generation construction. The sensitivity of CO2-e and carbonation estimates were tested on several different types of source demolition waste as well as subsequent construction applications using recycled concrete (RCA). Whole-of-life CO2-e estimates, including carbonation of RCA over the 1st and 2nd generations, were estimated and contrasted with conventional carbon footprints that end at the conclusion of the 1st generation. Findings - Following demolition, CO2 capture by RCA is significant due to the more permeable nature of the crushed RCA compared with the original built infrastructure. RCA also has considerably greater exposed surface area, relative to volume, than a built concrete structure, and therefore more highly exposed surface to react with CO2: it therefore carbonates more comprehensively. CO2-e estimates can be off-set by as much as 55-65% when including the contribution of carbonation of RCA built within 2nd generation infrastructure. Further offsets are achievable using blended fly ash or slag cement binders, however this study has focused on concrete composed of 100% OPC binders and the effects of RCA.Originality/value - Construction project estimates of life cycle CO2-e emissions should include 2nd generation applications that follow the demolition of the 1st generation infrastructure. Life cycle estimates generally end at the time of demolition. However, by incorporating the recycled concrete demolition waste into the construction of 2nd generation infrastructure, the estimated CO2-e is significantly offset during the 2nd generation lifecycle by chemical uptake of CO2 (carbonation). This paper provides an approach towards inclusion of 2nd generation construction applications into whole-of-life estimates of CO2-e.

INVESTIGATION OF DRIVERS AND MODES OF DIFFERENTIATION IN TURKISH CONSTRUCTION INDUSTRY

Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - The positive effect of differentiation strategy on achieving competitive advantage among construction companies is widely acknowledged in the literature. However, there exists only a limited number of studies in the construction management literature that investigate the drivers and modes of differentiation. The purpose of this study is to determine appropriate modes and drivers of differentiation strategy in the Turkish construction industry.Design/methodology/approach - In this study, based on the results of an extensive literature survey, a set of modes and drivers are defined as well as a conceptual framework to investigate their interrelations. Structural equation modelling (SEM) is proposed as an effective tool to investigate the relations between various factors of differentiation and data regarding the Turkish contractors have been used to demonstrate its applicability. Findings - The results demonstrate that construction companies can differentiate on two modes of differentiation, either on "quality and image" or "product variety and speed". Among the identified drivers, project management capabilities influence "product variety and speed related differentiation" and "quality and image related differentiation" directly; corporate management affects "quality and image related differentiation" directly, whereas corporate management influences "product variety and speed differentiation" indirectly. "Resources" has a strong direct effect on project and corporate management, in addition "resources" influences "product variety and speed related differentiation" and "quality and image related differentiation" modes indirectly through corporate and project management. Originality/value - Research findings may help companies to choose an appropriate differentiation mode considering their strengths and weaknesses related with the drivers. Although findings reflect the competitive environment prevailing in the Turkish construction industry, it is believed that the parameters identified in this study can further be used as a benchmark to conduct similar studies in other countries.

The how and why of plant-related fatalities in the Australian construction industry

Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - Drawing on the findings of coronial investigations, this research aimed to investigate the circumstances and causes of fatal incidents involving plant in the Australian construction industry. The analysis sought to provide greater insight into how and why fatal incidents occur and to inform recommendations for the prevention of fatal incidents involving plant.Design/methodology/approach - Fatal incidents involving plant were identified from the National Coronial Information System. In each case, the decedent was a construction worker and the incident occurred at a construction worksite. A systemic incident causation model developed by Loughborough University informed the identification of originating influences, shaping factors and immediate circumstances in each incident. Findings - Most of the incidents involved excavators, trucks and cranes and different classifications of plant were associated with different types of incident. The most common incident types involved people being run over by moving plant or struck by a moving object. Site layout and unsafe actions were the most commonly identified immediate circumstances. Shaping factors included site constraints and the design of plant, particularly visibility issues relating to ‘blind spots.’ Originating influences included the design of the permanent work and construction process.Research limitations/implications - The research highlights the usefulness of systemic incident causation models, such as the ‘Loughborough Model’ in the analysis of the causes of fatal incidents involving plant in the construction industry.Practical implications - The results indicate that plant-related fatalities occur as a result of a complex interplay of different causes, some of which are ‘upstream’ of the construction work. The use of innovative new site planning methods and active monitoring technologies to reduce the risk of collisions between people and plant should be considered. Originality/value - The analysis provides a more detailed qualitative analysis of the causes of fatal incidents involving plant than would be possible using national compensation data, which restricts analysis to a classification of the mechanism and agency of injury.

PREQUALIFICATION OF EGYPTIAN CONSTRUCTION CONTRACTORS USING FUZZY-AHP MODELS

Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - Contractor prequalification is a typical multiple criteria decision-making problem that includes both quantitative and qualitative criteria. The conditions surrounding the prequalification decision are often imprecise, subjective and uncertain; assessments are consequently made using linguistic approximations. Fuzzy set theory is specifically designed to handle qualitative and linguistic data based on approximations and provides a method of representing in numerical form the linguistic approximations used to describe the decision-maker judgments. However, fuzzy set theory has a weakness in identification of the relative weights of the decision criteria. On the other hand, one of the most accurate and easy method for identifying the relative weights is the analytic hierarchy process (AHP). Design/methodology/approach - The main objective of this paper is to develop a new integrated decision model composed of Fuzzy set theory and Analytic Hierarchy Process (AHP) methodologies approach that takes full advantages of the fuzzy set theory and the AHP. Two fuzzy approaches are considered, namely Chang’s extent analysis and Jaskowski aggregated group decision analysis.Findings - Both approaches are applied and validated on actual contractors in the Egyptian construction market. A software tool is developed to automate the calculations and a case study is provided.Originality/value - This research produced a new integrated decision model composed of Fuzzy-AHP methodology approach that takes full advantages of the fuzzy set theory and AHP for tackling the uncertainty and imprecision of contractor prequalification during the prequalification stage, where the decision-makers comparison judgments are represented as fuzzy triangular numbers. The default criteria used in this model had been collected through the literature review and experts’ opinion for building projects.

Fine-Tuning the Value and Cost of Capital of Risky PPP Infrastructure Projects

literatinetwork@emeraldinsight.com (Andreas Wibowo, Hans Wilhelm Alfen) — Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - The present paper introduces a new methodology taking risk behavior of decision maker into account to fine-tune the value a risky public-private-partnership (PPP) project and the corresponding cost of capital based on the target rate of return set by the project sponsor and the degree of project risks.Design/methodology/approach - The proposed methodology combines the cumulative prospect theory (CPT) to characterize the risk preference of the project sponsor and the monte carlo simulation to assess the project riskiness. The methodology requires a pre-set target rate of return that will define the relative gains and losses for a prospect theory project sponsor. Findings - As the project sponsor sets a greater target return, the probability of the project not meeting the target is accordingly greater. Given that losses have greater impact than gains on the decision, other things being equal, a higher target return leads to a higher value correction. It has also been demonstrated that the corresponding project's cost of capital can be up- or downadjusted depending on the project's riskiness which may result in a reverse preference to favor a higher risk scenario.Research limitations/implications - The methodology uses the CPT parameters that need to be further confirmed and validated if applied to value large risky projects like PPP investments. Originality/value - The proposed methodology offers a different approach to correctly value a risky PPP project by extending the application of the cumulative prospect theory that well explains the irrationality of human decision behavior under risk into a financial decision-making process. It takes the full benefit of simulation to understand project risks and assists financial decision-making.

Users’ Satisfaction Survey on Building Maintenance in Public Housing

literatinetwork@emeraldinsight.com (Anthony W.Y. LAI, Wan Miu LAI) — Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Purpose - A building maintenance scheme introduced by the Hong Kong Housing Authority in January 2006 employed contractors and public housing owner’s frontline representatives to provide inspection in the public rental housing tenants’ units and arrange corresponding repair works. This study aims to base on the public rental housing (PRH) tenants perceptions to measure maintenance contractor service quality performance.Design/methodology/approach - Questionnaire is used as the assessment tool which is derived based on the SERVQUAL approach to measure public rental housing tenants’ expectations and perceptions on maintenance contractor performance.Findings - The fiondings illustrate that dimensions of "tangible" and "reliability" have the largest discrepancy between expectation level and perception level. They are mainly related to the concern of disturbance to PRH tenants brought by maintenance contractors in respect of manpower arrangement. These findings support that there is a need for maintenance contractors to impose more manpower resources to minimize the adverse impacts to PRH tenants.Research limitations/implications - The service quality performance survey could provide a reference for conductuing the survey continuously which could help develop a systematic benchmark in matching service delivery and expectation for future improvement. The SERVQUAL gap analysis would help identify any gaps between expectations and perceptions among various concerned parties, i.e. services providers (contractors) and direct customers (owner’s frontline representatives). Practical implications - The service quality gap findings could provide a reference for the frontline representatives to organize and improve services of the building maintenance scheme to be implemented in other public rental housing units.Originality/value - The value of this this study could serve as a frame work for further study in conducting service quality performance survey in other public housings and extend the performance measurement approach to other similar tasks in construction project areas.

ECAM Editorial Issue 20.4

literatinetwork@emeraldinsight.com (Jayshree Lakha) — Fri, 28 Jun 2013 00:00:00 +0100

Abstract

Not available.