Abstract

CPM and PERT are well established as the main tools to plan and control construction projects. However, the planning and control of construction field operations has to consider the minute-by-minute complexity of bringing multiple resources together to produce a work package. At this level, the quality of each resource has major effects on the productivity, quality or safety. The rapidly changing dynamic nature of the site and the shifting quality of critical factors requires a new model to achieve zero-process waste. This paper presents a new construction management model that embraces a waste-based feed-forward control methodology designed to eliminate process- or muda-waste rather than high productivity. It extends the concept of the seven mudas by Taiichi Ohno to include all construction specific wastes.  Of special interest of the discussed work is the waste effect of poor communication along the supply chain. After discussing the rational of the model the paper highlights the results of field observations in the area of foundations and steel construction. Wireless cameras were used for continuous-time studies to measure productive and wasted labor-hours before and after changes in the material supply logistics were implemented.

Abstract

In Chile, as in many South American countries, AASHTO-93 is the current official method for the design of asphalt pavements. The method gives an estimated number of 80 kN standard axle loads (W18) that the pavement can withstand for a certain serviceability. A safety factor is then applied to W18 to take into account the confidence level and the estimated variance of the inputs used in the method, whereby the magnitude of the structure’s life cycle is estimated. Normally, data used in the AASHTO-93 method are assumed to be deterministic, disregarding their random nature. This paper presents a probabilistic assessment of the AASHTO-93 pavement design method under Chilean conditions, which provides a set of probability density functions (PDFs) that allow a probabilistic estimation of the pavement life cycle in terms of the value W18. To achieve the goal, we developed a simulation model based on a sample of 13 groups of roads located throughout Chile.

Abstract

Due to the high aggressiveness in which the concrete structures are exposed, many researches have been developed in this area and search for materials with superior mechanical performance and durability has been the target of the researchers of concrete technology. Therefore, concrete obtained from the microstructure engineering are needed. Being composites made of fine grain particles and a low water/binder ratio, these materials have dense matrix by optimizing the packing of granular materials. Thus, this paper uses the concept of particles packing in the design of special concretes, analyzing the durability of these materials by determining the water absorption by immersion and by capillary, and chloride ion penetration. The properties of concrete designed based on this concept are compared to high performance concrete designed from conventional methodology, indicating superior properties in terms of durability.

Abstract

Construction industry accounts for a significant part of the solid waste generated in urban centers. In part this is due to a lack of culture of reducing the generation or reuse of waste. This sector may improve this situation, seeking to develop management systems. The objective of this paper is to present a proposal for a management system to plan and control construction waste in small and medium sized construction firms. A case study on construction sites was performed in a building company of Novo Hamburgo, Brazil. The planning and control waste system was developed as based on the production system existing in the firm and results point to the feasibility of implementing this system.

Abstract

The aim of this paper is to define alternative construction processes for a building with reinforced concrete slab floors, thereby estimating which ones are most beneficial in terms of their execution time and cost. Three alternatives were proposed to solve the deadlines of the construction process: Shoring and Striking; Shoring, Clearing and Striking; and Shoring, Reshoring and Striking, considering 2, 3 and 4 consecutive shored floors. In order to evaluate what processes are valid, first it is necessary to calculate the loads during the construction process using the New Simplified Procedure and subsequently check whether or not the striking condition is fulfilled in each of the construction operations. Regarding the studied building, the feasible construction processes were: Shoring, Clearing and Striking with 3 and 4 consecutive shored floors.

Abstract

The objective of this paper is to investigate the importance of Building Information Modelling (BIM) functions in the construction industry from professionals’ views in the Gaza Strip-Palestine. A questionnaire survey was employed in this study and 270 professionals in the construction industry have responded to the questionnaire; data were analyzed using exploratory factor analysis. The study findings indicated that BIM functions are significantly needed and important for professionals in the construction industry in Gaza Strip. Findings of this study revealed three components of BIM functions: data management and utilization in planning, operation and maintenance, visualized design and analysis, and construction and operation. Energy optimization was found as the highest important function of BIM of the first component as there is a high demand for sustainable building and sustainable development. A functional simulation in order to choose the best solution for lighting and energy was the highest important function of the second component. This function will assist in identifying methods to reduce resources consumption and increase on-site renewable opportunities. Model-based cost estimation was found the highest important function in the third component. Professionals in the construction industry will benefit from the findings presented in this paper by understanding the BIM functions which will encourage them to apply BIM tools that will lead to a substantial improvement in the performance of construction projects.

Abstract

This article discusses the economic benefits of the implementation of the sustainable building LEED (Leadership in Energy and Environmental Design) certification in the Centro Ático building located in Bogotá, Colombia. Initially, the consumption of water and electricity are determined, as well as the costs of construction and operation of the building under its original design (built without regard to the parameters set by LEED). Then, strategies to allow the Centro Ático building to obtain the LEED GOLD New Construction V3 2009 certification are proposed and the economic increases associated with them are calculated. Also, the new consumption of water and electricity, when these strategies are applied (modified design), and their operating costs are calculated. Finally, indicators of economic goodness of investment are determined using a cash flow analysis.