Sudhir Misra

Ranking and classification of construction coordination activities in Indian projects

The efforts of contractors, consultants and owners need to be appropriately coordinated in large civil engineering projects, whose success can be defined in terms of compliance to schedule, economy in cost, adherence to quality, and non‐occurrence of disputes. Based on the hypothesis that coordination activities affect the different dimensions of project success differently, and that different stakeholders prioritize the activities differently, a questionnaire survey covering senior Indian construction professionals was carried out. For this a list of 59 coordination activities influencing successful completion of a construction project was drawn up. These coordination activities were ranked for the four success dimensions using statistical tools on the responses received. ‘Regular monitoring of critical path activities’; ‘monitoring the budget on all activities and taking corrective action’; ‘application of sound technical practices’; ‘implementation of all contractual commitments’ are the most important coordination activities corresponding to schedule, cost, quality and no‐dispute performance criteria, respectively. Results show that project coordination issues can be addressed by attending to essentially the four broad groups of coordination activities—resource handling, planning, team building and contract implementation. Findings presented in the paper could interest construction professionals and help them identify and concentrate on important coordination activities.

Corrosion of Phosphoric Irons in Cement Grout

Abstract Corrosion behavior of three cement-grouted phosphoric irons (Fe-0.11P-0.028C, Fe-0.32P-0.026C, and Fe-0.49P-0.02C, wt%) was studied using the potentiostatic polarization technique in 5% so...

Quantifying Changes in Surface Characteristics of Concrete due to Progressive Deterioration

AbstractScaling, erosion, and cracking are some manifestations of deterioration of concrete surfaces due to chemical attack, exposure to cyclic freezing and thawing, and so forth. Though a rating o...

Application of Bayesian updating for real-time schedule estimation in a concreting operation

Ready-Mixed Concrete (RMC) delivery schedules should be carefully planned due to the limited time span between mixing and placing. The scheduling of RMC supply is challenging to both contractors and plant managers because of multiple operational issues such as traffic conditions and unloading delays. Simulation has been applied to address this challenge; however, the unique and complex nature of construction environments raises a validity issue in the use of previous datasets as input for the simulation of a new operation. Based on this recognition, the idea of using real-time data has been proposed to address the input data validity issue and to enhance the predictability of the simulation model. One important concern that has not yet been fully addressed regarding this issue is the amount of data collection required to yield a valid sample such that the output is sufficiently reliable. To answer this question, this paper uses a Bayesian updating technique with data collected from a concreting operation in a high-rise building project in Abu Dhabi. Through the case study it is concluded that the Bayesian forecasting technique has great potential for providing a better statistical representation of operational data and improving the predictability of the simulation model.

Estimating Critical Corrosion for Initiation of Longitudinal Cracks in RC Structures Considering Phases and Composition of Corrosion Products

AbstractPremature deterioration and reduction in the life of reinforced concrete (RC) structures due to corrosion of the embedded reinforcing steel bars is a major concern across the world, and the time for formation of longitudinal cracks has been largely accepted as the “service life” of the structure. It is also widely known that the formation and deposition of expansive corrosion products (of iron) on the bars exert radial pressure on the cover concrete, which finally cracks. In this case, it is reasonable to assume that the composition of the corrosion products, in terms of the different phases of the oxides and hydroxides, and their relative percentages, play a vital role in determining the loss of weight (of iron) that causes sufficient pressure for the onset of such longitudinal cracks. It is interesting that virtually no quantitative information is available in the literature on this subject. The main thrust of the present work is to understand the effect of composition and relative amount of dif...