Irtishad Ahmad

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Professor and Head, Civil Engineering, American University of Sharjah. Founding Director of the Moss School of Construction, Florida International University. Expertise in concrete technology, construction organizations, information and communication technology in construction.

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Supply Chain Management in Construction Scope, Benefits and Barriers

UPPLY chain management (SCM) is a concept that has originated in the manufacturing industry to co... more UPPLY chain management (SCM) is a concept that has originated in the manufacturing industry to control logistics. It represents a management process by which enterprises administer and control the worldwide network of suppliers, factories, warehouses, distribution centers and retailers through which raw materials are acquired, transformed and delivered to customers. In construction, procurement and procurement related activities occur during all phases of a construction project. Because of inevitable complexity and fragmentation of the construction process, supplies of resources like equipment, labor, material and other services may not be always available on time, in right amounts and in the desired quality and price. An overall management process like supply chain management is essential to monitor and control all such logistic activities. The concept of supply chain management in construction outlining its origins in manufacturing is introduced in this paper. The effectiveness of the supply chain management has been evaluated with its potential benefits to the construction industry. A list of possible barriers, which may affect the application of supply chain management concept in the construction industry, has also been presented. Finally, a simplified model for supply chain management in the construction industry is presented.

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Impacts of COVID-19 on the Use of Digital Technology in Construction Projects in the UAE

Buildings

The construction industry has been incorporating digital technology over the last two decades, al... more The construction industry has been incorporating digital technology over the last two decades, albeit gradually, as “technology-push” continues to overcome customary and traditional passivity typical in the sector. The objective of the study presented in this paper is to investigate how digital technology is making a headway in the construction industry as a consequence of COVID-19. For the purpose of this paper, digital technology applications are divided into three groups: data acquisition, processing, and communication. The methodology involved conducting a questionnaire survey among the construction professionals in the UAE. The survey included questions on the extent of use and level of investment on the three types of technology in three periods—pre-COVID, during COVID, and post-COVID. The results clearly show the increasing level of usage of digital technology in the construction industry from pre-COVID to during COVID and post-COVID periods. Among the three categories, commu...

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Develop Epoxy Grout Pourback Guidance and Test Methods to Eliminate Thermal/Shrinkage Cracking at Post-Tensioning Anchorages: Phase II

This research report contains guidance for eliminating thermal and shrinkage cracking in epoxy gr... more This research report contains guidance for eliminating thermal and shrinkage cracking in epoxy grout pourbacks used in post-tensioned anchorages. In this study, an experimental investigation of a selected epoxy grout pourback material and finite element analysis on the full-scale pourback specimens using the same pourback material were conducted. The study was undertaken to better understand the pourbacks' failure mechanisms and provide guidelines and methods for eliminating them. Additionally, field investigation of epoxy grout pourbacks cracking was made at two bridge sites in Tampa and Miami. Based on a comprehensive literature review, manufacturer and contractor feedbacks, field investigation, and full-scale testing potential factors affecting epoxy grout pourback were determined to be the pourback size, shapes (particularly shapes with obtuse corner), ambient condition and concrete substrate's temperature. The results of the full-scale testing and finite element analysis indicated that the primary cause of pourback failure was due to thermal cracking. The manufacturer-provided peak exothermic temperature did not reflect what was measured in the full-scale specimens as well as in the researchers' own laboratory test, which were significantly higher. It was found that both the peak exothermic temperature and the maximum thermal stress increased as the volume-to-surface (V/S) ratio increased. It should be noted that the V/S ratios calculated in this report were based on the volume divided by the area of the exposed surfaces (the face of the epoxy grout not in contact with the concrete) in ft. The shapes also played a significant role particularly shapes with obtuse corners. The thermal cracks found in the field and full-scale specimens were full-depth cracks that penetrated through the epoxy grout. Therefore, it is recommended that these cracks should be immediately sealed. To avoid the thermal cracks, it is highly recommended, based on the findings of this study, that the V/S ratio of the epoxy grout be limited to 0.30 ft and 0.35 ft for irregular (S-type) and rectangular (R-type) shaped pourbacks, respectively.

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Construction Disputes in the UAE: Causes and Resolution Methods

Buildings, 2020

Claims and disputes occur frequently in the construction industry between different contracting p... more Claims and disputes occur frequently in the construction industry between different contracting parties, mainly the owner, the designer and the contractor. Consequently, valuable time and a significant amount of money are lost. The United Arab Emirates (UAE) construction industry, one of the most vibrant sectors globally, is experiencing a high level of construction disputes and claims. This paper aims to identify and assess the major causes of disputes in the UAE and weigh the effectiveness of the methods used for their avoidance and resolution. The sources of disputes, and their avoidance/resolution methods, were identified through a comprehensive literature review. A survey was then developed and sent to 150 construction professionals. Fifty-four responses were received and analyzed. The results show that the top five sources of disputes in the UAE are variations initiated by the owner, obtaining permit/approval from the municipality and other governmental authorities, material c...

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Evaluacion De Las Practicas De Gestion De Riesgo De Los Contratistas Generales De Florida Evaluation of Florida General Contractors Risk Management Practices

Construction is a highly risk-prone industry with not a very good track record of coping with ris... more Construction is a highly risk-prone industry with not a very good track record of coping with risks. The participants in the industry, as a result, have been enduring the agonizing outcomes of failure in the form of unusual delays in project completion, with cost surpassing the budgeted cost and sometimes failed to meet quality standards and operational requirements. Thus, an effective analysis and management of construction associated risks remains a big challenge to the industry practitioners. This paper via, questionnaire survey and in-depth interviews, evaluates the current practices of risk analysis and management adopted by the general contractors in the Florida construction industry and presents the comparison with four other US states considered to have highly profitable and modernized construction industry. The results reveal that in the Florida construction industry, risk analysis and management techniques are rarely used by the general contractors due to a lack of knowled...

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Lumps and balls in high-slump concrete: reasons and remedy

The objective of this research was to investigate the reason lumps occur in highslump concrete an... more The objective of this research was to investigate the reason lumps occur in highslump concrete and develop adequate batching procedures for a lumps-free high-slump ready-mix concrete mix used by the Florida Department of Transportation. Cement balls are round lumps of cement, sand, and coarse aggregate, typically about the size of a baseball that frequently occur in high-slump concrete. Such lumps or balls jeopardize the structural integrity of structural members. Experiments were conducted at the CSR Rinker concrete plant in Miami, Florida, based on a protocol developed by a team of Florida Department of Transportation (FDOT) concrete engineers, Rinker personnel, and Florida International University faculty. A total of seventeen truckloads were investigated in two phases, between April 2001 and March 2002. The tests consisted of gathering data by varying load size, discharge rate, headwater content, and mixing revolutions. The major finding was that a usual load size and discharge rate, an initial headwater ratio of 30%, and an initial number of revolutions of 100 at 12 revolutions per minute seem to produce a lump-free high-slump concrete. It was concluded that inadequate mixing and batching procedures caused cement lumps. Recommendations regarding specific load size, discharge rates, number of mixing revolutions, and initial water content are made. Clear guidelines for a high-slump concrete batching protocol can be developed, with further testing based on these research conclusions. v TABLE OF CONTENTS CHAPTER

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Computing Technology Usage in Construction Contractor Organizations

Computing technology in the construction industry can be broken down into automation and informat... more Computing technology in the construction industry can be broken down into automation and information and communications technology (ICT). Construction automation entails the use of computers to replace and/or enhance a variety of jobsite applications including surveying, the control of equipment, and the installation of prefabricated units using Global Positioning System (GPS) technologies and advanced robotic systems. Construction ICT entails the use of computer systems that are capable of capturing, organizing, storing, analyzing, exchanging, transmitting, and sharing information. Automation and ICT have previously been recognized as tools for increasing competitive advantage in the construction industry, however, this industry has been slow to adopt these technologies especially when compared to the manufacturing and service industries. The construction industry has undergone changes in recent years which have resulted in many construction organizations attempting to implement some form of automation and/or ICT. Currently, the construction industry is characterized by the rapid development of jobsite automation technologies which has resulted in a large amount of real-time data being produced in the field. This data is oftentimes not recorded and not converted into meaningful information. As a result, the industry has yet to experience the full benefits of using computing technology in construction. This paper will discuss how a construction contractor can increase his competitive advantage by integrating the real-time data collected from jobsite automation with ICT technologies thereby creating a total jobsite management tool.

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Generalized Method for Analysis of Pavement Management Database

In Florida, pavement materials are periodically and systematically sampled and tested. The test r... more In Florida, pavement materials are periodically and systematically sampled and tested. The test results are recorded in the databases of a pavement management system (PMS). The PMS databases are large and are currently stored on a remote mainframe system that is usually not directly accessible by an end user at a PC terminal with a modem connection. This project involves the development of a mainframe computer tool to allow the remote users to conveniently and instantly perform initial on-line statistical analyses on the Florida Department of Transportation's PMS databases. The SAS/AF software was used to create user-friendly interactive windowing applications. As a product of the Statistical Analysis System (SAS) software, SAS/AF provides interactive user interfaces to all the data access, management, analysis, and presentation features. The software uses the Frame class as the foundation for GUI-based applications. The Frame class provides windowing capabilities to SAS/AF applications. It can contain visual controls and non-visual components for creating a user interface. Through the Frame class, windows and dialog boxes, menu bars or banners, and application help can be created. However, SAS/AF versions 7 and up do not support build-time development of FRAME entries in the mainframe operating environments. Consequently, applications developed in other desktop environments must be ported to a mainframe, i.e., frames have to be created on a PC or other systems that support frame entries and then ported to the mainframe. The mainframe SAS/AF application program was designed to query a subset of records for analysis. Currently, querying non-index variables is likely to consume more CPU time than a data source is allowed. As a result, users can only use index variables to query and create subset databases of less than 86,030 records. This report documents the development process and serves as the user manual for the SAS/AF mainframe program developed. The procedure for porting the SAS/AF code from a PC to the mainframe is also included.

DATA WAREHOUSING IN THE CONSTRUCTION INDUSTRY: ORGANIZING AND PROCESSING DATA FOR DECISION-MAKING Data warehousing in construction

Construction organizations are critically dependent on data. But data must be available in suitab... more Construction organizations are critically dependent on data. But data must be available in suitable forms for use. Timely access to useful and meaningful information can enable construction companies gain competitive edge, increase client satisfaction, expand market share and enhance profitability. Vast amounts of construction operational data are scattered across multiple, dispersed and fragmented departments, units or project sites. In this paper, we present data warehousing as an emerging database management technology that can provide the resource for decision-making. We point out the difference between an operational database -used for transaction processing; and a data warehouse -intended to be used for analytic processing in management decision-making in the context of construction organizations.

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Introduction to the Special Issue on Information and Communication Technology (ICT) in AEC Organizations: Assessment of Impact on Work Practices, Project Delivery, and Organizational Behavior

Journal of Management in Engineering, 2015

Information and communication technology (ICT) has changed and continues to change almost every a... more Information and communication technology (ICT) has changed and continues to change almost every aspect of our daily lives. Our personal lives, social interactions, educational systems, business atmosphere, and corporate culture-everything has changed in one way or another due to advances in the field of ICT. The construction industry is no exception. ICT provides an unprecedented opportunity as well as enormous challenges to the construction industry. Only 25-30 years ago, a photocopy machine was considered the most important ICT tool used in a construction office. Things have changed vastly and dramatically. What happened during the last two decades cannot be characterized as mere evolutionary dynamics. It is no less than a revolution. From computing technology of the past to what we now know as ICT is a huge leap. The AEC (architecture, engineering, and construction) industry cannot afford to be just a spectator; the industry must take a proactive role in reshaping its own culture and systems in order to get the most out of the ICT revolution. That was the motivation behind this special issue. We attempted to present to the readers of the Journal of Management in Engineering the latest state of ICT as being applied and incorporated in the AEC industry, advancements in the ICT over the last two decades and their impact, current research topics being pursued by the researchers on ICT in construction and engineering project management, and above all we wanted to explore opportunities and challenges ICT presents to the AEC industry. ICT encompasses all forms of computing technologies (hardware, software, telecommunications, social media, etc.) that can be used to create, store, exchange, and utilize information in various forms. The AEC industry already embraced many ICT techniques and tools in the area of visualization, data analysis, communications and collaboration, information sharing and management, and information modeling . Rapid adoption of smart phones and tablet devices in the AEC industry not only confirmed the need of quick information sharing but has also changed the mode of work practices at construction jobsites and offices. Similarly, building information modeling (BIM) has changed the way the buildings are conceived, designed, constructed, and operated. The use of BIM has encouraged the integration of the © ASCE A2014001-1 J. Manage. Eng.

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Transformational capabilities of ICT: A technology management perspective in construction

PICMET '08 - 2008 Portland International Conference on Management of Engineering & Technology, 2008

(1) The construction industry typically lags behind in adopting technology. (2) Given the fact th... more (1) The construction industry typically lags behind in adopting technology. (2) Given the fact that the process of construction is critically dependent on relevant, accurate and timely information, ICT can play a very important role in the industry. (3) The industry is actually missing out on the crucial advantages offered by ICT. ICT is used by and large as mere

System-of-Systems Modeling of Performance in Complex Construction Projects: A Multi-Method Simulation Paradigm

Computing in Civil and Building Engineering (2014), 2014

In this paper, a framework is proposed for the investigation of base level components in the asse... more In this paper, a framework is proposed for the investigation of base level components in the assessment of performance in construction projects. A multimethod simulation paradigm is proposed to provide a structure for bottom-up abstraction and modeling of construction projects based on micro-behaviors at the base level. The proposed framework and the model are used in a numerical example related to concrete pouring to evaluate the impacts of micro-behaviors at the base level on project performance. The findings of the case study highlight the importance of modeling the base level components and demonstrate the capability of the proposed framework in enhancing the assessment of performance in construction projects.

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Critical Look into the Relationship between Information and Communication Technology and Integrated Project Delivery in Public Sector Construction

Journal of Management in Engineering, 2015

AbstractThe relationship between integrated project delivery (IPD) and information and communicat... more AbstractThe relationship between integrated project delivery (IPD) and information and communication technology (ICT) in the context of public sector construction in the United States is critically examined in this paper. While IPD is gaining significant attention lately from educators and researchers alike, the current body of knowledge lacks information about how project owners—the key stakeholders in construction who decide on the type of project delivery system—perceive IPD. In addition, there has been little to no research investigating the relationship between IPD and ICT, taking the degree (extent) of use and type of ICT (internal versus external) into consideration. This study attempts to fill these research gaps. Using 59 survey data points collected from various public sector owners in the United States, this study investigates two research questions: (1) the perception of IPD characteristics on project delivery effectiveness, and (2) the perception that ICT fosters IPD. The perception regarding...

Factors Influencing Integrated Project Delivery in Publicly Owned Construction Projects: An Information Modelling Perspective

Procedia Engineering, 2014

The objective of this paper is to underline the factors influencing the implementation of integra... more The objective of this paper is to underline the factors influencing the implementation of integrated project delivery (IPD) in public sector construction projects. These factors are broadly classified under legal, organizational and technological categories. Further the role of information modeling to foster the integration in project delivery is discussed. Focus is placed on the aspects/characteristics of information modeling that can contribute to implementation of integrated project delivery. Traditional project delivery methods have been found by researchers as inefficient and litigious. As a result, the construction industry is in a critical need of alternative delivery methods.IPD has emerged as a solution, although its implementation is not without challenges. Therefore factors influencing its implementation should be identified as a step towards its probable use in the future for public-sector construction projects. Owners, particularly the public ones, are apprehensive due to various factors. The purpose of this paper is to investigate these factors and suggest an information modeling approach to overcome the impediments.

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Safety and Economy of Shoring/Reshoring Schemes in Construction of Multistory Concrete Buildings

Construction Research Congress, 2003

The objective of this paper is to develop a computerized model for selecting a cost-effective sla... more The objective of this paper is to develop a computerized model for selecting a cost-effective slab shoring/reshoring scheme for construction of multi-story concrete buildings. The model is based on two main criteria: safety during construction and cost-effectiveness. As construction of highrise concrete buildings moves up, shoring of lower slabs are stripped and placed on top of the just stripped slabs in order to cast the upper slabs. Some of the stripped lower slabs must be reshored to carry the additional construction load. Both safety and cost must be considered in a reasonable manner in order to determine the optimum shoring/reshoring combination for a particular construction. Factors such as cycle time (duration between casting of two consecutive slabs), concrete strength, building configuration and member dimensions, cost of shoring and reshoring materials, and labor productivity must be taken into account in order to analyze and determine the optimum combination. In this study, thirty customary and practical shoring/reshoring combinations are investigated. SHORING2 program, developed by Chen and Mossalam in 1991 is used to analyze load distribution and check safety of construction. A database module in Access  is developed to store various possible building configuration data, labor and materials unit prices, and other material properties data. Another module developed in Excel  is used to compile and further analyze results from SHORING2 and Microsoft Access  modules. As a result, information on cost and duration of the construction is obtained. In the final operation of the system, the results are displayed in Access  module graphically. These results provide helpful guide to the users in order to choose the best shoring/reshoring combination.

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Construction of a Bridge in a Developing Country: A Bangladesh Case Study

Leadership and Management in Engineering, 2003

This paper presents a case study of the construction of the Jamuna Bridge, the 11th longest bridg... more This paper presents a case study of the construction of the Jamuna Bridge, the 11th longest bridge in the world. The bridge crosses the Jamuna River (the main channel of the Brahmaputra River in Bangladesh) from Bhuapur on the east bank to Sirajganj on the west, linking the eastern and northwestern parts of Bangladesh. In addition to two carriageways with two lanes each for road transport, the bridge also carries a dual-gauge (meter-gauge and broad-gauge) rail track, a 750-mm-diameter natural gas pipeline, and a 230-kV electrical transmission line across the river. Built at a cost of about $950 million, the Jamuna Bridge is one of the most expensive infrastructure facilities in the Third World. This project posed various challenges to the government of Bangladesh and the international agencies involved. Technical, financial, social, and political challenges had to be overcome, yet despite the complexity and inherent difficulty of this megaproject it is considered a success story. The factors that contributed to the successful construction of the Jamuna Bridge in Bangladesh are chronicled in this paper. T he Jamuna Bridge is currently the 11th longest bridge in the world and provides the first fixed crossing across the Jamuna River linking the eastern andnorthwesternpartsofBangladesh. The bridge is approximately 110 km northwest of Dhaka, the capital city of Bangladesh. Before the bridge was constructed, the only way to cross the Jamuna River was by slow-moving ferryboats. Traffic jams at the ferry terminals often lasted for several days. A journey that used to take 12 to 36 hours from Dhaka to the northwestern trading townofBogranowtakesonly4hours(JMBA2002). The initial feasibility studies of the project started in 1972 and were completed in 1976. These were followed by a tech-

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Estimating Work Zone Road User Cost for Alternative Contracting Methods in Highway Construction Projects

Journal of Construction Engineering and Management, 2009

ABSTRACT Highway construction often causes an additional road user cost (RUC) to motorists due to... more ABSTRACT Highway construction often causes an additional road user cost (RUC) to motorists due to traffic flow interruption and congestion in work zones. Consequently, facility owners, such as the Florida Department of Transportation (FDOT), are often interested in using alternative contracting methods such as A+B contracting to expedite construction. Although many of these contracting methods rely on the RUC to determine incentives or disincentives, no standard method for RUC calculation is available to FDOT district engineers. In addition, existing methods are neither practical nor user-friendly for determining incentives or disincentives. This study intends to develop a RUC calculation procedure for the FDOT that focuses on using data that are easily accessible to FDOT district engineers, such as drawings and maintenance of traffic plans. The procedure is developed based on traffic analysis methods published in the Highway Capacity Manual, previous studies on user benefit analysis and work zones, and empirical data specific to Florida. Case studies are used to illustrate the procedure and to compare it with two other existing models, the Arizona model and the queue and user cost evaluation of work zone model, through correlation analysis, comparison of calculation assumptions, and data input analysis. This study shows that the suggested procedure produces consistent RUC estimates.

Information technology (IT) and integration in the construction industry

Construction Management and Economics, 1995

... We contend that appropriate IT investment and management's commitment and ability to pro... more

Construction project teams for TQM: a factor-element impact model

Construction Management and Economics, 1997

ABSTRACT

Development of a decision support system using data warehousing to assist builders/developers in site selection

Automation in Construction, 2004

Site selection process depends on a number of spatial and business-related factors, making it a c... more Site selection process depends on a number of spatial and business-related factors, making it a complex decision-making task. It is common for the decision makers to use their subjective judgment and gut feelings based on their experience in selecting the most appropriate site for development. The reason is that data for site selection originate from varied sources and are not organized in a format that decision makers can readily use to derive any meaningful information. One possible solution of this problem is to develop a decision support system (DSS) to help retrieve data from different databases and information sources and analyze them in order to provide useful and explicit information. Based on this concept, a DSS is presented in this paper as an aid to builders/developers in site selection for residential housing development. The prototype DSS is developed using data warehousing technology, which is a fairly recent database management technique. It is an improved approach for integrating data from multiple, often very large, distributed, heterogeneous databases and other information sources. Data warehousing is based on online analytical processing (OLAP) concept. The OLAP analyzes data using special data warehousing schemas and enables users to view data using any combination of variables. The users can also generate data trends over a period of time to make any forecasts. First reviewed in this paper are the concepts of data warehousing, OLAP and advantages of the data warehouse over traditional databases in the context of decision making. Next, a step-by-step methodology is presented to illustrate the different stages of the prototype DSS development. The DSS design is illustrated with particular emphasis on the development of data warehousing schemas and analytical processing techniques. The prototype DSS has been developed with input and refined with feedback obtained from selected local builder/developer companies. Finally, the application of the prototype DSS for selecting the most appropriate residential site for development from among a list of several available sites is presented.

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Irtishad Ahmad

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