Constructability Practices to Manage Sustainable Building Knowledge

Construction professionals have knowledge and competencies that can help improve the design and delivery of sustainable buildings. The introduction of construction knowledge during design using constructability practices has been shown to improve design and project performance. From a process perspective, this paper examines specific constructability techniques that can help manage sustainable building knowledge throughout the design process. Through scientific research, four constructability practices employed at the Pentagon renovation are assessed for their capability at managing sustainability input from contractors. The four practices are: (1) the use of an integrated organizational team to champion the effort; (2) physical and computer building models (mock-ups); (3) on-board reviews; and (4) lessons learned workshops. Twenty-one specific principles are then identified to provide further guidance to industry practitioners. These practices and principles pinpoint methods to help manage sustainable building knowledge, especially that made available by construction professionals during design and construction.     

Constructability Rankings of Construction Systems Based on the Analytical Hierarchy Process

This paper uses the quantitative decision-making technique, the analytical hierarchy process, to derive prioritized scales for (1) the constructability factors; and (2) the relative contribution of common construction systems in a building superstructure comprising structural frames, slabs, envelopes, roof, and internal walls toward constructability. The identified constructability factors show that to enhance constructability design requirements should be easily visualized and coordinated by site staff, while designs should allow economic use of contractors’ resources and enable contractors to develop and adopt alternative construction details. The precast method is rated as the most constructible construction method, indicating its better performance in facilitating efficient and safe construction in the busy urban environment in Hong Kong. However, the methodology adopted in this study should be of international interest, especially for those desirous of improving constructability of designs with different contextual backgrounds.     

Constructability Analysis of the Bridge Superstructure Rotation Construction Method in China

Constructability analysis can provide valuable input to optimizing urban bridge construction in terms of reducing impacts on traffic, safety, and overall project budget and duration. This paper presents a constructability analysis of the superstructure rotation method for bridge construction. The method includes building the bridge parallel to the obstacle being overpassed (a river or a highway) and then rotating the superstructure into place. The method has been used successfully in over one-hundred bridges (mostly in China). The paper documents two case studies of bridges that used this method and provides an analysis of the constructability of the method. This includes identification of the factors influencing the constructability of the methods and lists of design and construction objectives/strategies that support the constructability of bridges using this method.     

Assessment of Constructability Practices among General Contractors

Modern construction has been characterized as a complex and fragmented process. These characteristics have produced a decrease in the quality and cost efficiency of projects. It has been proven that this problem can be partially overcome by implementing constructability, which is based on the integration of construction knowledge into design (as was done in the past). The implementation of constructability is not easy because it represents a change in the way things have been done in the last century. Prior research has found a lack of constructability efforts among participants in the construction industry, especially general contractors. Because builders can play an important role in implementing constructability, this paper assesses constructability practices among general contractors. The data were obtained from a mailed survey. It was found that contractors applied constructability concepts and participated during the earliest phase of the projects more often than is thought. In addition, the findings showed that constructability practices differed depending on the characteristics of the organization, the type of work performed, and the type of contractual arrangement.     

Constructability Analysis in the Design Firm

The timely execution of a construction project is very important to the owner, who makes plans and commitments on the basis of the project’s anticipated completion date. Failure of design professionals to consider how a builder will implement the design can result in scheduling problems, delays, and disputes during the construction process. Constructability of design is a subjective scale that depends basically on a number of interdependent project-related factors. Many design firms have a formal (explicit) constructability program that is launched as early as the conceptual planning stage of the project. This research examines design professionals’ efforts to pursue constructability and provides recommendations for performing constructability reviews in an efficient and effective manner.     

Organizing Constructability Knowledge for Design

Construction contractors have significant constructability expertise to contribute to the design process of projects. To utilize this expertise most effectively, the right information must be made available to the design team at the proper point in time and at the appropriate level of detail. Current methods for utilizing construction knowledge in design have made significant advances to improving projects. However, they are typically rudimentary: unstructured, not very efficient, and rely heavily on reviews. Organizing constructability information according to its use in the design process will allow project teams to take the best advantage of the construction expertise. This paper introduces a model for organizing constructability information based on timing and levels of detail. The model differs from current approaches because of this focus. How the model was developed is described. It is tested on six case study projects to assess applicability on different projects. An illustrative example is provided using a detailed case study of the Pentagon renovation project to show how the model can be used as a metric to guide constructability input during design.     

Integrating Constructability into Project Development: A Process Approach

The National Cooperative Highway Research Program initiated a research project to develop a constructability review process (CRP) for transportation facilities. The basic objective of this research was to develop a systematic approach and methodology for constructability reviews. This paper describes the development of a CRP that meets the National Cooperative Highway Research Program's research objectives. A process approach is followed to integrate constructability improvements into project development for transportation projects. A function modeling tool is used to portray the interface between the CRP and the project development process. The function modeling tool captures constructability functions and information necessary to perform these functions. The research method to develop the CRP is presented. The CRP has three phases corresponding to planning, design, and construction of a transportation project. Seven constructability functions are performed in each phase. The model was tested using two transportation projects of different complexity.     

Constructability and Economics of FRP Reinforcement Cages for Concrete Beams

This paper presents a quantitative economic analysis and a qualitative constructability analysis of three-dimensional fiber-reinforced plastic (FRP) reinforcement cages for concrete beams. Material, labor, and life-cycle costs are provided, and construction practice aspects are discussed. The results of the analyses indicate that prefabricated FRP cages can offer benefits to the construction industry. Although the initial costs of the FRP materials are likely to be higher than those of steel rebar, there is a significant potential for cost savings due to reduced maintenance and labor costs, as a result of the corrosion resistance of the FRP and the increased construction productivity. When direct life-cycle costs are considered, FRP reinforcements already constitute, in many cases, an economically competitive alternative to conventional steel reinforcement in adverse environments. If, in addition, the indirect cost savings as well as quality and safety issues are considered, the FRP reinforcement may be even more competitive.     

Contemporary Design-Bid-Build Model

Empirical research was performed into the hypothesis that a substantial number of building performance engineering tasks on design-bid-build projects are typically provided by entities associated with the construction phase, not with the architect-engineer (AE) of record. This hypothesis is contrary to the traditional understanding of design-bid-build and is theorized to result from increased time pressures on AEs, decreased AE profit margins, AEs’ attempts to minimize liability, increased design and construction specialization, and increased prefabrication. Project technical specifications were analyzed for 20 $5–45M building construction projects and 16 individuals directly associated with these projects were interviewed. It was found that 35 building performance engineering tasks were required by the project specifications to be performed by entities associated with the construction of the buildings. This large number of delegated design tasks suggests the conventional understanding of the design-bid-build process is not accurate. The increasing fragmentation of the design and construction process may have implications for the efficiency of communication on design-bid-build projects, lean construction processes, and constructability.     

Incorporating Maintainability in Constructability Review Process

Life cycle cost or total cost analysis of a facility begins with the initial design concept and ends with the decommissioning of the facility. Decisions made during the design and construction phases routinely consider only the construction costs when analyzing the constructability of the project. Often the impacts of such decisions on the maintenance requirements for the facility are not fully appreciated and are therefore not formally addressed. The concept of “maintainability” addresses this concern and is a logical extension of the constructability concept. As such, maintainability may be incorporated as a part of the formal constructability review process (CRP). This article describes a model format for incorporating the best practices for maintainability into the CRP. The added life cycle value of incorporating maintainability into the CRP can only be assessed by analysis of accurate and complete maintenance cost data. Insights from such an analysis may facilitate more accurate estimates of the total costs of facilities.     

Impacts of Constructability Improvement

An analysis of the construction resource utilization tradeoffs, which occur from constructability improvements, provides insight into the constructability improvement process. Matrices of construction and engineering impacts likely to result from constructability improvements are presented. Constructability improvements collected on a large industrial construction project are analyzed for their impact to the job. Frequencies of occurrence of both desirable and undesirable impacts are noted, as are the cost‐significances of the various impact types. Constructability strategies and methods for achieving the most cost‐beneficial impacts are presented. Numerous findings are presented, such as the following: (1) The likelihood of delays may be decreased most effectively by increasing engineering information availability and understandability; (2) the amount of required construction manpower may be most effectively decreased by simplifying the design, combining design elements, and seeking optimal design‐originated construction techniques such as optimal construction systems, modularization, and improved design details. Of course, additional engineering effort may be required; and (3) construction activity durations may also be most effectively decreased by seeking optimal design‐originated construction techniques.     

Constructability Practices among Construction Contractors in Indonesia

The concept of constructability in the United States or buildability in the United Kingdom emerged in the late 1970s, which evolved from studies into how improvement can be achieved to increase cost efficiency and quality in the construction industry. It is an approach that links the design and construction processes. The studies in the Unites States, United Kingdom, and Australia have demonstrated that improved constructability has lead to significant savings in both cost and time required for completing construction projects. However, in implementing constructability improvement, it is important to consider the uniqueness of the construction industry in a specific country. This paper presents the study performed on the construction contractors in Indonesia with regard to their current constructability practices and its impact on the project performance. The study shows that many contractors in Indonesia have been implementing part of the constructability concept in their projects. The concepts that usually applied during the construction stage as part of the overall construction plan were planning the sequence of field tasks and analyzing layout, access, and temporary facilities     

Acute lymphoblastic leukemia in children. Progress in life expectancy

Heuristic construction knowledge generated while contracting is seldom recorded and transferred to other workers. Experiences of past mistakes as well as efficient work practices are crucial means for saving money, time, and improving the safety and quality of construction. With the rising costs of construction and the increased demand of time constraints on contractor schedules, few members of the construction industry can afford to waste time and resources on errors or ineffective work practices. The Constructability Lessons Learned Database (CLLD) prototype described in this paper is a leading edge method of automatically gathering, systematically organizing and efficiently applying vital construction information to a contractor's daily activities. This paper presents a review of previous and current attempts at database constructability programs, uses of constructability feedback systems, challenges to develop and utilize such systems, and an overview of the design and development of the CLLD prototype. The overview describes knowledge elicitation techniques used to gather constructability knowledge, the design of the system (organizing and classifying construction information for efficient retrieval and expansion), and system's implementation, validation, and operation. The conclusion discusses future extensions of the CLLD concept in the construction industry.     

Interactive 3D CAD for Effective Derrick Crane Operation in a Cable-Stayed Bridge Construction

The high expectation of esthetic and functional quality in modern civil infrastructure has resulted in the increased demand for long span bridges. In advanced or developing countries, long span bridges such as cable-stayed and suspension bridges are considered even as landmarks that symbolize the prosperity or culture of the region. These long span bridges require higher level of design and construction technologies than other types of bridges. In particular, the construction of cable-stayed bridges involves precise and sophisticated operation of construction equipment such as derrick cranes. However, it is not easy to plan the operations of a derrick crane before the actual construction process takes place. Unexpected spatial constraints in the construction site may hinder the smooth operation of a derrick crane, which leads to lower than expected productivity and safety. This study applies interactive three-dimensional (3D) computer aided design (CAD) to the derrick crane operation for the purpose of identifying potential problems. Construction managers can have the two way process with the 3D CAD system to interactively test their construction plans and scenarios. The case study shows that the interactive 3D CAD system significantly improves the constructability of the cable-stayed bridge construction.     

Contractors’ Views of the Potential Causes of Inconsistencies between Design and Construction in Saudi Arabia

The study identifies the causes of inconsistencies between the design and construction of large building projects. To achieve the study objectives, a questionnaire survey was carried out to collect information on potential causes of inconsistencies at the project design and construction interface. Responses from 27 contractors were analyzed. The results suggest that the involvement of designer as consultant, communication gap between constructor and designer, insufficient working drawing details, lack of coordination between parties, lack of human resources in design firm, lack of designer’s knowledge of available materials and equipment, and incomplete plans and specifications were considered as the most important causes of the project design and construction interface inconsistencies. On the other hand, project management as a professional service, weather conditions, nationalities of participants, involvement of the contractor in design conceptual phase, unforeseen problems, involvement of the contractor in design development phase, and government regulations were the least important causes of inconsistencies between professionals at the project design and construction interface in large building projects.     

Interface Characteristics and Laboratory Constructability Tests of Novel Fiber-Reinforced Polymer/Concrete Piles

Conventional pile materials such as steel, concrete, and timber are prone to deterioration for many reasons. Fiber-reinforced polymer (FRP) concrete composites represent an alternative construction material for deep foundations that can eliminate many of the performance disadvantages of traditional piling materials. However, FRP composites present several difficulties related to constructability, and the lack of design tools for their implementation as a foundation element. This paper describes the results of an experimental study on frictional FRP/dense sand interface characteristics and the constructability of FRP–concrete composite piles. An innovative toe driving technique is developed to install the empty FRP shells in the soil and self-consolidating concrete is subsequently cast in them. The experimental program involves interface shear tests on small FRP samples and uplift load tests on large-scale model piles. Two different FRP pile materials with different roughness and a reference steel pile are examined. Static uplift load tests are conducted on different piles installed in soil samples subjected to different confining pressures in the pressure chamber. The results showed that the interface friction for FRP materials compared favorably with conventional steel material. It was shown that toe driving is suitable for installation of FRP piles in dense soils.     

Value Engineering and Optimal Building Projects

The goal of any engineering design is to obtain an optimal solution to the design problem. This paper examines how value engineering contributes to the process of obtaining an optimal solution to the design problem for a building project. The factors that determine a building project and its costs are listed and these factors fall into two groups; one group relates to specific engineering systems, while the other group is general in character and relates to the whole building. Value engineering is effective because its procedures give opportunities for raising design issues associated with the latter group of factors as well as for providing for peer-review of the design. A summary of other methods of optimal design—such as design for manufacture and assembly (DFMA), concurrent engineering, and total quality management—is given, and these methods are compared with value engineering. Cost minimization in building construction is discussed with examples from the writer's experience on building projects in West Africa and the Middle East.     

Constructability State of Practice Report

This report reviews guidance on constructability programs from a variety of sources and presents the current practice of constructability. The advice of several organizations and researchers is summarized to describe expectations for ideal constructability. Actual current constructability practice, based on results and analysis of a Constructability State of Practice survey, is described. Approximately 100 owners, architects, engineers, consultants, contractors, and construction managers answered the survey’s ten questions and provided written comments. The results provide a picture of current constructability practices in the architecture, engineering, and construction (AEC) industry and progress in recent years. Major conclusions include: (1) constructability has gained acceptance throughout the industry; (2) constructability efforts are clearly beginning in early project phases; (3) a wide variety of constructability techniques and new technologies are being implemented; and (4) obstacles to improving constructability remain, but may be changing. Finally, recommendations are provided based on areas where constructability practice can still be improved. This report is relevant to both industry practitioners and researchers.     

Constructability Concepts in Kuala Selangor Cable-Stayed Bridge in Malaysia

The writers formulated a case study of the Kuala Selangor Cable Stayed Bridge to examine the application of the constructability concepts particularly during the conceptual planning and the design phases of the project. This paper presents the advantages of implementing the constructability concepts and the barriers that were encountered when applying these concepts during the planning and design phases of the cable stayed bridge project of Kuala Selangor in Malaysia. The writers concluded that barriers to constructability implementation that are related to the owner were the major impediments in the application of constructability concepts during the early conceptual planning phase. The opinion of the engineer was another factor behind nonapplication of some other concepts. At the same time, many others were implemented due to the awareness and opinion of the engineer and his ability to control their application.