Incorporating the effect of weather in construction scheduling and management with sine wave curves: application in the United Kingdom

The impact of (adverse) weather is a common cause of delays, legal claims and economic losses in construction projects. Research has recently been carried out aimed at incorporating the effect of weather in project planning; but these studies have focussed on either a narrow set of weather variables, or a very limited range of construction activities or projects. A method for processing a country’s historical weather data into a set of weather delay maps for some representative standard construction activities is proposed. Namely, sine curves are used to associate daily combinations of weather variables to delay and provide coefficients for expected productivity losses. A complete case study comprising the construction of these maps and the associated sine waves for the UK is presented along with an example of their use in building construction planning. Findings of this study indicate that UK weather extends project durations by an average of 21%. However, using climatological data derived from weather observations when planning could lead to average reductions in project durations of 16%, with proportional reductions in indirect and overhead costs

Main flexible pavement and mix design methods in Europe and challenges for the development of an european method

Pavement and mix design represent one of the key components within the life cycle of a road infrastructure, with links to political, economic, technical, societal and environmental issues. Recent researches related to the characteristics of materials and associated behavior models both for materials and pavement, made it appropriate to consider updating current pavement design methods, and especially in the USA this has already been in process while in Europe uses of the methods developed in the early 1970s. Thus, this paper firstly presents a brief historical overview of pavement design methods, highlighting early limitations of old empirical methods. Afterwards, French, UK and Shell methods currently in use in Europe will be presented, underlining their main components in terms of methodology, traffic, climatic conditions and subgrade. The asphalt mix design and modeling in Europe are presented with their inclusion in the pavement design methods. Finally, the main challenges for the development of a European pavement design method are presented as well as the recent research developments that can be used for that methodThe second author would like to express the support of Portuguese National Funding Agency for Science, Research and Technology (FCT) through scholarship SFRH/BSAB/114415/ 2016. This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.info:eu-repo/semantics/publishedVersio

Modelling and parametric study of the re-anchorage of ruptured tendons in bonded post-tensioned concrete

The contribution of ruptured tendons to the residual strength of bonded post-tensioned concrete structures is currently assessed based on pre-tensioned concrete bond models. However, this approach is inaccurate due to the inherent differences between pre-tensioned and post-tensioned concrete. In this paper, a non-linear 3D finite element model is developed for the re-anchoring of a ruptured tendon in post-tensioned concrete. The model is validated using full-field displacement measurement from 33 post-tensioned concrete prisms and previous experimental data on beams from the literature. The influence of different parameters was investigated, including tendon properties (i.e. diameter, roughness), duct properties (i.e. diameter, thickness, material), initial prestress, concrete strength, grout strength, grout voids, stirrups, and strands, on the tendon re-anchorage. The most influential parameters are found to be tendon and duct properties

Large-Scale Rainfall Simulation and Cyclic Plate Loading Test of Wicking Geotextile-Stabilized Base

The detrimental effects of moisture on roadway performance are well-known, thus drainage is crucial to roadway performance. Open-graded aggregates or non-wicking geotextiles are often used as drainage layers in a roadway system. These drainage layers rely on hydraulic gradient to remove water and are only effective under a high degree of saturation. Partially saturated soil can still contain too much moisture and be problematic to roadway performance. An innovative geotextile, the wicking geotextile, contains deep-grooved wicking fibers that can generate suction hence enable the wicking geotextile to remove moisture from unsaturated geomaterials. To verify the unsaturated drainage effect of the wicking geotextile on the mechanical behavior of a road section, three large-scale cyclic plate loading tests were conducted in this study. Each test was comprised of a 0.3 m thick base course over a 0.9 m thick subgrade. The three sections included a control section, a non-wicking geotextile-stabilized section, and a wicking geotextile-stabilized section. Geotextiles were installed at the base course-subgrade interface. Each section first underwent a rainfall simulation and then a 6-day drainage period. Cyclic plate loading tests were conducted at the end of the drainage period. The amounts of water distributed over and exited from the section during and after the rainfall simulation were recorded. The permanent deformations of the cyclic plate loading tests were measured to evaluate the performance of the roadway section. The test results show that the wicking geotextile provided fast drainage in the base layer and improved the performance of the roadway section in the cyclic plate loading test significantly