82 publications from this institution
Construction errors can have significant effects on project performance. Yet, any attempt to tackle error should be driven by the ability to understand its archetypal nature. This study aims to analyze a variety of construction errors at the execution stage, in order to develop a comprehensive set of categories that shall provide insights about the effect of different error types on the industry. We investigate a database provided by an authoritative source, which includes a number of 256 construction errors that occurred in the year 2009 in Dubai construction industry. Results from this study reveal that the most common error arose from ‘poor workmanship’ which accounted for 21% of the total encountered faults. The next most common types arose from the ‘usage of impaired materials’, followed by the ‘deviation from an intended dimension’. These observations infer that the majority of construction errors are driven by workers’ lack of skill or competence. Moreover, it suggests that execution-oriented errors are the major cause of faults and accidents rather than design errors.
Assessment of the mechanical performance of internally-defected components or struc-tures is of crucial importance to many industrial fields such as aerospace, automobile, marine, construction etc. Most of the studies available in the literature include only analytical or numerical solutions, due to difficulty in the manufacturing of a testing sample with a specific internal defect geometry for experimental evaluations. In this study, Fusion Deposition Modeling (FDM) was utilized in the 3D-printing of Polylactic Acid (PLA) samples with internal cracks, aiming to assess their impact on the samples’ mechanical performance. The defect geometry, orientation, location along the sample gauge length and the influence of the process parameters, such as the infill percentage and the material color, were investigated. The influence of the internal defects is more pronounced for a 100% infill rate if compared with a 50% infill rate as a consequence of the porosity. A maximum drop of ~14% in the peak load of defect-free samples was recorded due to the presence of the internal defect. Moreover, the additive color to the PLA material might contribute to the material strength. Generally, the findings of this work could open another door for utilizing the additive manufacturing in many research areas, with potential industrial applications relevant to the assessment of internally-defected materials.
