Project risks must be managed to deliver construction projects on time and within budget. In recent years, the New Engineering Contract (NEC) provides an alternate contracting method for procuring construction projects. As stipulated in the NEC contract, NEC risk register must be used to record any project risks. The risk register is designed to record each risk item in the context of textual description, likelihood, and consequence. However, it is time-consuming to identify, quantify, and analyse NEC project risks based on experience, questionnaire, simulation, and data-mining approach. Any method to fully utilise the records of NEC risk registers of past projects for managing NEC project risks remains unexplored. As such, a data-driven approach is proposed to categorise common risks of NEC projects and to analyse risk rating of risk categories by combining the use of text mining analysis and decision tree analysis. A practical case study in Hong Kong is used to illustrate the method of application. Top four common types of NEC project risks, which are ground and utilities, design information, structures, and workmanship, were identified, quantified, and analysed. The new approach helps NEC project planners to identify, quantify, and analyse NEC project risks time-efficiently.

Accurate prediction of the construction duration is imperative to the reliable cash flow analysis during the project planning phase when feasibility analysis is carried out. However, lack of information and frequent changes that occur as a result of a negotiation process between the owner and the designer in defining the project scope make it difficult to compute real-time construction duration. Domestic and foreign models for calculating the construction durations cannot be readily applied to computation of construction duration for general office buildings in Korea specifically during the project planning phase as there is a limit in its applicability due to numerous restrictions. Moreover, there are no preceding studies suggesting different computational approaches to predict the entire construction duration for office buildings with the approximate construction duration concept during planning phase. Therefore, based on the collected performance data, this study proposes a multiple linear regression model that facilitates reliable prediction of approximate construction duration for office buildings in the project planning phase. The model will allow the owner and other stakeholders to predict the real-time construction duration using the basic information on office buildings and to assess the construction durations incorporating frequent changes during the project planning phase.

Triggering innovation among Small-and-Medium Construction Firms (SMCFs) is of paramount importance to gear up the growth of construction firms. Thus, this study aims to develop a Capability-Based forecasting model for innovation development in SMCFs. Built on 157 questionnaires, the model was tested using partial least squares (PLS) technique of structural equation modelling (SEM). The practicality and robustness of this model was then validated by 12 experts. Findings affirm SMCFs making use of multiple Capability-Based approaches would be able to secure their performance via innovation activities. For academia, the new model contributes to the stream of construction innovation management by integrating both technological and organizational innovations in a single framework. For practitioners and policymakers, the model offers valuable input for continuing growth of SMCFs via innovation.

The distribution of fiber orientation is an important factor in determining the mechanical properties of fiber-reinforced concrete. This study proposes a new image analysis technique for improving the evaluation accuracy of fiber orientation distribution in the sectional image of fibers reinforced concrete. The article is devoted to research the systematic evaluation of fiber-cuts through the image processing software. Mathematical representation of the final dispersal of fibers in steel fiber-reinforced concrete is incorporated into a programmed evaluation software. The software detects fibers and classified according to their axes of rotation angle and size of the identified ellipse detection area. Image processing algorithm and detecting fibers has been developed only for these research purposes. Detection area is randomly inserted via steel fiber reinforced concrete structure. The results show the average value of uniformity in the fiber-samples produced in the laboratory.

Regardless of potential benefits of design for safety (DFS) concept for lifecycle safety management in construction industry, DFS adoption as an early intervention has been slower than expected. While existing research mainly con­centrates on construction and operation phases, the role of design phase in construction safety management is always ignored. To validate the influence of DFS concept on lifecycle safety performance, this research conducted an incident case analysis (ICA) based on 442 cases collected from lifecycle subway projects, and a subway design-incident classification model (SDICM) was developed to help identify their relationship to DFS concept. Network theory was applied to study the interdependence of 22 subsystems obtained from China’s code for metro design in lifecycle safety performance. Research findings show 236 out of 442 accidents are linked to DFS. Compared with construction phase, operation phase is more susceptible to design work. Station Building (SB), Section Construction (SC), Platform Screen Doors (PSD), Vehicle Systems (VES) and Power Supply Systems (PSS) are identified as having the highest number of accidents. The results of network analysis are consistent with ICA and demonstrate the safety interdependence of subsystems. This research can help improve the cognizance of DFS, and the identified subsystems should be given priority in the design phase.

It is of great importance to facilitate the risk assessment process in construction projects because risk assessment is a requirement in most legislation and safety standards. A great majority of construction SMEs (Small and Medium Enterprises) are not familiar with risk assessment concepts and methods. In particular, SMEs are very likely to have difficulty finding the qualified personnel or time to carry out a proper risk assessment. The method introduced in this paper has some distinct features. The method introduces a new method of risk assessment, replacing the traditional definition of probabilities with control levels because they are easier to implement and yield more accurate risk scores. The method was practically applied on 22 construction SMEs. From the practical application, it was observed that the method was found to be user friendly and the SMEs found it easy to update their risk strategies during various construction stages in their projects. The proposed risk assessment method introduces a powerful and practical control level strategy which would develop a safer, healthier and more competitive workplace for construction SMEs.

The objective of the study presented in this paper is to determine the characteristics of the scaffolding supply chain in a liquefied natural gas (LNG) infrastructure project. This research is significant as the outsourcing of scaffolding is integral to its use and productivity toward LNG infrastructure project completion. As such, this paper presents the re­search undertaken on the subcontracting of scaffold manufacturing, supplying and delivering. It focuses upon the organi­sations, management and control in scaffolding subcontracting. A comparative analysis of three organisations was car­ried out to reveal issues with current practice in manufacturing, supplying and delivering scaffold products for assembly onsite. Their management and control approaches are also compared and contrasted. It is found that, while the divided contract approach may help save costs, enhance market exposure and is ideal when choice of subcontractor is limited, its risks can impact upon the entire project and be difficult for the contractor to control. The limited background in scaf­folding studies and importance of subcontracting within LNG infrastructure projects has made this research timely. This paper identifies issues in relation to quality assurance, warranties and rework, which have the potential to mitigate any cost benefits obtained from subcontracting practices within this supply chain.

This paper presents a simple method to determine dynamic modulus master curve of asphalt layers by con­ducting Falling Weight Deflectometer (FWD) for use in mechanistic-empirical rehabilitation. Ten new and rehabilitated in-service asphalt pavements with different physical characteristics were selected in Khuzestan and Kerman provinces in south of Iran. FWD testing was conducted on these pavements and core samples were taken. Witczak prediction model was used to predict dynamic modulus master curves from mix volumetric properties as well as the bitumen viscosity characteristics. Adjustments were made using FWD results and the in-situ dynamic modulus master curves were ob­tained. In order to evaluate the efficiency of the proposed method, the results were compared with those obtained by us­ing the developed procedure of the state-of-the-practice, Mechanistic-Empirical Pavement Design Guide (MEPDG). Re­sults showed the proposed method has several advantages over MEPDG including: (1) simplicity in directly constructing in-situ dynamic modulus master curve; (2) developing in-situ master curve in the same trend with the main predicted one; (3) covering the large differences between in-situ and predicted master curve in high frequencies; and (4) the value obtained for the in-situ dynamic modulus is the same as the value measured by the FWD for a corresponding frequency.

The aim of the research programme was to investigate flexural behaviour of steel fibre reinforced self-com­pacting concrete (SFRSCC). The specimens were in a form of slabs reinforced with steel fibres (of three lengths and two shapes) by volumes of 1.0% and 1.5%. Two methods of casting slabs were examined. The experimental tests per­formed on 80 specimens cut from slabs (1.2×1.2×0.15 m) involved tests of mechanical properties, digital image analysis (DIA), and X-ray computed tomography (XCT) procedures. Determination of distribution of fibres by DIA and XCT was required to assess relationships between mechanical properties and the casting methods. The tests were conducted according to RILEM TC 162-TDF (2002) and EN 14651:2005+A1:2007(E) recommendations. The study confirmed the technological problems associated with uneven distribution of steel fibres in SCC matrix. Based on the performed analy­sis, the flexural tensile strength of SFRSCC cannot be described with the formulas used for SFRC. Fibres are generally oriented parallel to the direction of concrete mixture flow in a mould. This phenomenon is influenced by fibre length and the location of concrete casting point (CCP). It was also demonstrated that the flexural behaviour of tested elements is influenced by CCP.

A new testing method and estimation of the fracture toughness in Mode III (antiplane shear) of concretes contain­ing: 0, 20 and 30% volume content of the class F fly ash (FA) was proposed. Fracture toughness tests were performed on axial torsional machine MTS 809 Axial/Torsional Test System using special device. The Device for the fracture toughness test at the Mode III fracture consisted of the cylindrical specimen with the formed initial crack, steel plates, and screws with washers securing the specimen in the press holders. The specimens applied for experiments were cylinders with dimensions of 150/300 mm, having an initial circumferential notch made in the half-height of cylinders. The specimens were subjected to pure torsion. The studies examined effect of FA additive on the parameter KIIIc. 20% FA additive causes a small increase of the KIIIc in comparison to the concrete without the FA, while 30% FA additive causes a significant decrease in fracture tough­ness. The fracture surfaces of the specimens analysed macroscopically were planar. Scanning microscopic observations (SEM) indicate that in the fracture surfaces multilevel cracks occur in the shape of semicircles.