Overcoming Barriers to P2 and Recycling for Construction Waste

Estimates of construction and demolition (C&D) waste entering landfills range from 20 to 33% of the total waste stream volume. Although waste estimates are difficult to verify, it is clear that, even at the low end of this estimate range, there is significant potential for diverting C&D materials from landfills. A study by the California Environmental Protection Agency (2006) found that new residential construction comprised about 10% of the C&D waste stream. Although much of the construction waste that currently and typically goes to landfill can be recovered, effective waste management in the residential construction industry remains an elusive goal. Guided by the ADOP2TTM model (Lindsey, 1998, 1999) for diffusion of innovation, this research project worked toward accelerating the adoption of waste minimization and pollution prevention (P2)/recycling practices by Illinois home builders. Major phases of the study included: establishing partnerships with home builders in two Illinois counties; identifying and quantifying typical waste streams from residential construction; identifying priority waste materials for P2/recycling, local best management practices, and barriers to P2/recycling faced by home builders; implementing P2/recycling demonstration projects in two counties; developing case study fact sheets to document the procedures and results; and disseminating the results of the demonstration projects.published or submitted for publicationnot peer reviewe

Decision support system to maximize economic value of irrigation water at the Egyptian governorates meanwhile reducing the national food gap

The water resources and agricultural policies in Egypt tend to minimize the food gap, increase self-sufficiency, maximize the economic value of water, decrease the cultivated area of voracious crop water and optimize the water allocation and use. The main goal of the present study is developing a decision support system that can be utilized to assist in achiving these polices and stategies. The decision support system was applied to: (i) analyze of the current situation of the consumed water and the cultivated areas by main crops and their net return, (ii) calculate economic value of irrigation water for main crops at twenty two governorates in Egypt, and (iii) solve a linear optimization problem where the objective function is maximizing the economic value of the irrigation water, and finally (iv) propose an optimal cropping pattern at the Egyptian governorate level. The paper concludes that proposing a cropping pattern at the governorate level is essential where it provides a reliable and accurate view of the economic value of irrigation water rather than the national level. The proposed cropping pattern reduces the national food gap and the cultivated areas of voracious crops water, and saves the irrigation water. Alternatives to utilize the saved water due to the proposed cropping pattern are suggested

WORKING THROUGH UNFORSEEN UNCERTAINITES USING THE OODA LOOP: AN APPROACH FOR SELF-MANAGED CONSTRUCTION TEAMS

ABSTRACT Construction operations are dynamic and time sensitive. The management response to issues on site is typically a consequence of and the response to an event that has already taken place. Decisions and actions that are delayed are often rendered ineffective because of the constantly changing site conditions. The sudden emergence of the situation and the dynamic nature of its evolution needs to be addressed with flexibility and fluidity based on an appropriate assessment of the issues at hand. The need to increase the effectiveness with which self-managed teams perform under such conditions cannot be overstated and clearly requires a theoretical framework that can provide an interpretation of the underlying cognitive processes and selected responses in the face of dynamically evolving environments, and the intricate interrelationships among all constituents of the process. This paper presents the Observe-Orient-Decide-Act (OODA) loop as the theoretical interpretation by which to understand, influence, and predict the performance of self-managed construction teams. The paper begins by introducing the constructs of the OODA loop, followed by exploring its application to understand and evaluate the performance of self-managed teams in construction. The paper then posits that the effectiveness of self-managed teams found in construction is a function of the collective OODA loop speed of the group. The paper concludes with research possibilities associated with the OODA Loop, and develops guidelines for embracing uncertainty in the project, and production management phases. KEY WORDS Lean construction, OODA loop, last planner system, self-organizing teams

Effects of elastic modulus on behavior of polymer coated fiber modified short concrete beams

Polymers have been one of the mostly and effectively used materials all over the world recently. They have been gaining popularity for various purposes in the concrete industry last couple of decades as well. They have the ability to increase the strength and durability of the concrete products. Moreover, polymers in concrete industry can also be considered as a sustainable product since they achieve the requirements of the consumers without adversely affecting the environment, health and the economy. Fiber-modified short beams are structural members commonly used in construction industry. To enhance their physical properties, various methods have been developed; however, most of them have been considered costly and time consuming. In this study, it was concluded that one major physical property, strength, of fiber-modified concrete short beams could be improved by using polymer as a coating material. Hence, the capacity and probably the service life of those beams could be improved. Furthermore, proper polymer coating may reduce the maintenance costs. In this study, polymer coating is applied for fiber modified short concrete beams. The change in modulus of elasticity was investigated as the identifying parameter between various coated short beams since it is an important parameter in the design and analysis processes of the beams. The elastic moduli for various regions of the world were derived from compressive strength results. The maximum deflection values were computed for each region and each polymer coating as well. Finally, the most effective polymer type and coating were discovered according to the maximum deflections obtained for simply supported beam approach.Journal ArticleFinal article publishe