Innovative contracting in infrastructure design and maintenance
This paper describes the results of research into the contract arrangements and design processes for contractors in the road infrastructure industry. The changing institutional environment has led the industry to believe that more opportunities can be realised to the benefit of society (lower cost, higher quality, more efficient design and design process) when contractors are allowed more 'design freedom' in their contracts with governments. We have explored the technical design space, and developed a framework to structure this space. Next, we identified, through many indepth interviews and case studies, a number of technical, organisational and institutional opportunities, threats and barriers for granting more design space. Finally, the paper discusses the conclusions that could be drawn from the mapping of the opportunities onto the bottlenecks, and it shows that much can indeed be gained, but that many of these opportunities for cost reduction or value improvement are hampered by large, inert institutional settings.
Assessing Reverse Logistics in South African Construction
The purpose of this paper is to advance the benefits of an efficient reverse logistics system in construction. The paper argues that building material and waste removal operations could be optimized by the application of reverse logistics in a construction context. Though the larger research entails extensive use of a number of qualitative approaches, this particular paper reports on a multi case study investigation conducted in the City of Cape Town. Present knowledge of logistics in general and transportation in particular, within South African construction is relatively limited. Emphasis is more frequently placed on supply chain management (SCM) without reference to the fundamental need to understand its pre-eminent subsets, such as transportation. For instance, building materials and waste removal transport operators in construction still operate as independent businesses. As a result, these vendors do not synchronize their operations. The utilization of reverse logistics in a construction context could improve vehicle utilization and reduce vehicular movements while simultaneously improving the service being provided to customers. In other words, there appears to be a major scope for reducing wastes related to unnecessary movement, conveyance and unnecessary motion in the process.
Development of intelligent models for ravelling using neural network
The most unacceptable damage observed on porous asphalt is raveling. Therefore it is important to predict this detriment accurately and understand it deeply. Artificial neural network (ANN) was employed to predict raveling using time-series raveling and climate, construction and traffic factors. The necessary data was obtained from SHRP-NL database. Model I is able to forecast raveling low, moderate and high with correlation factor of R/sup 2/=0.986, 0.926 and 0.976. Model II provided sensitivity analysis indicating the relative contribution of factors related to climate, traffic factor, thickness, roughness and age. Color contours illustrated lots of facts such as heavy traffic and low thickness cause raveling on old asphalt at cold rainy days. Model III and its optimized version were developed to analyze relation between material properties and raveling. ANN proved to be a powerful technique to predict and analyze raveling opening great opportunities for development of ANN models for other detriments.