With its growing emphasis on sustainability, the construction industry is increasingly interested in environmentally friendly concrete produced by using alternative and/or recycled waste materials. However, the wide application of such concrete is hindered by the lack of understanding of the impacts of these materials on concrete properties. This research investigates and compares the performance of nine data mining models in predicting the compressive strength of a new type of concrete containing three alternative materials as fly ash, Haydite lightweight aggregate, and portland limestone cement. These models include three advanced predictive models (multilayer perceptron, support vector machines, and Gaussian processes regression), four regression tree models (M5P, REPTree, M5-Rules, and decision stump), and two ensemble methods (additive regression and bagging) with each of the seven individual models used as the base classifier. The analytical results show that, with appropriate parameter sett...

Construction safety culture is becoming a typical proactive safety performance measurement and strategy for safety improvement. However, there is no accepted industry wide definition for safety culture. There is also no clear distinction between safety culture and safety climate. So far, little research has investigated how safety programs can be developed to improve safety culture and climate, which in turn can be used to assess the effectiveness of these programs. This paper presents a study that examined the multilevel safety culture and climate to assess a newly launched safety program. Specifically, three different questionnaires were used to survey 71 top executives, 229 site management personnel, and 350 field workers, respectively. This study found wide acceptance of the program across all three groups, strong management accountability in enforcing safety, and a positive general safety climate among workers. The results demonstrated the program’s overall effectiveness in building positive ...

The severity of interface issues and the necessity of interface management (IM) have not received adequate recognition from both industry and academia. The understanding of interface issues is still insufficient and the proposed or employed measures are unilateral, which result in unsatisfactory IM performance in construction projects. After establishing IM’s importance in the construction industry, this paper presents a multiperspective approach that systematically explores comprehensive cause factors for various interface issues. From six interrelated perspectives, namely people/participants, methods/processes, resources, documentation, project management, and environment, hierarchical cause factors are identified and presented in a structured way. These cause factors are further converted into a series of interface management and control elements that allow for the development of an object data model and a systematic model-based IM strategy dealing with all interface issues. The multiperspective approach outperforms other research methods that analyze selected interface issues in a loose and isolated way. The findings contribute a holistic view of what causes interface issues as well as provide a solid theoretical basis for practitioners and researchers to seek all-around IM solutions.

Safety management is becoming increasingly important in the construction industry. Effective safety management not only reduces contractors’ incident rates and compensation costs, it also enhances productivity and efficiency in project execution. In addition, better safety performance increases contractors’ competitive advantage in the market by providing better values to their clients. This paper presents a case study of an on-site safety management program launched by a general contractor (GC). The initial findings, based on quantitative measurement of incident rates and safety violations, are presented to evaluate the effectiveness of the program. Overall, the program is effective in reducing jobsite accidents/incidents and safety violations in the GC’s organization while having less effect on subcontractors’ safety performance. This research also finds no linear relationship between incident rates and safety violation rates, indicating that these two measurements are uncorrelated and that both of them need to be used in evaluating jobsite safety performance and the effectiveness of a safety program.

The intense complexity of interfaces in a construction project makes information technology (IT) applications a must for effective interface management (IM). This largely requires a unified, accurate, and efficient way of modeling interface information. Conventionally, interfaces are simply modeled as dependencies/relationships between project entities; various interface information is loosely presented in different ways, which reduces the accuracy and completeness of interface information as well as the efficiency in information exchange and application. This paper introduces an object view of interfaces and its inherent interface object modeling technique, and then presents an interface object model (IOM) framework. The IOM is the first in the literature that aims to systematically define the data structure and dependencies of interface information for modeling. It is at the core of a conceptually proposed systematic model-based IM strategy. When fully developed, the IOM can be used to accurately model multiple types of interfaces. This will greatly enhance the quality and interoperability of interface information, promote IT applications for IM, and ultimately improve interface-related project performance.

Many university campuses in the United States are working toward their sustainable goals by adopting energy or green building policies, which require Leadership in Energy and Environmental Design (LEED^®) certification for new construction and major renovation projects. Because LEED certification heavily relies on whole building energy simulation to demonstrate building energy performance improvement, it is often assumed that the finished buildings will achieve the predicted level of energy efficiency. This paper presents a study that compares the energy model predictions with actual energy performance of three LEED buildings on a university campus. The study shows that one of the campus LEED buildings consumed twice the predicted energy usage while causing a high level of occupant dissatisfaction. Further investigation reveals a variety of contributing factors for these issues and provides insights to improve green building policy and practice. Not only are the research findings important for this particular campus (Ohio State University) on its way to sustainability, they also have widespread ramifications for other university campuses.