Papers by Keyword: Construction

Abstract: The development of drag and lift balance aimed to modify and creating a measuring instrument that may be used in the field of aerodynamics or in testing aerodynamic properties. This measurement is in the form of wind speed on an object model such as airfoils, building models and automotive technology. This design uses an open circuit wind tunnel with a low turbulence subsonic type, with a maximum air speed of 30 m/s. The exsisting wind tunnel still uses an analogue measuring instrument which is then modify in a digital arduino-based for drag and lift balance measuring instrument with a drag and lift sensor maximum load of 1kg (v=30m/s) and maximum air speed of 50m/s. The Measuring instrument is calibrated using a 1kg weight test equipment for testing with the test object model (spherical, hemispherical, cylindrical, cube) and three types of airfoil models. The test results are in the form of drag coefficient (C_d) and lift coefficient (C_L). The coefficient of drag is greatest in the cube shape and lowest in the sphere, but will decrease in value at a speed of 20 m/s. In the airfoil, the values ​​of C_d and C_L have the same trend with the literature with an uncertainty value of less than 10%. The value of C_L / C_d will increase as the angle of attack increases, but can very significantly depending on the fluid, airfoil, and aircraft type.

Abstract: Construction and demolition waste (CDW) accounted for almost 36% of total waste produced in the European Union in 2018. Growing recovery rates are achieved but mainly for low-value applications. Variable composition and characteristics undermine customers’ confidence who prefers primary materials with certified properties and at more competitive value/cost. Zero energy and waste targets are driving to rethink the waste value chain, necessitating a search for new technologies to reduce carbon emissions and waste volumes towards a more efficient and circular system. This paper presents an outline of the approaches to enhance CDW management that will be developed in the newly funded Horizon Europe project RECONMATIC. This project will develop digital and automated solutions to support advanced CDW management towards zero targets and will explore applications of technologies at different phases of the asset whole life cycle. Technical issues will be considered in aspects such as material segregation, pre-demolition audits, selective deconstruction, waste traceability procedures, as well as broader economical-societal issues such as business model, health & safety, sustainability, and technology readiness level. RECONMATIC aims to usher a paradigm change in CDW management by helping the construction industry taking a step change in circular economy development.

Abstract: Soil as a building material is gaining renewed interest from academia, and the construction sector, mainly for fabricating low-environmental impact homes. The fabrication of houses with soil using traditional methods such as adobe, cob, and rammed earth dates back to ancient times. However, emerging construction technologies, such as 3D printing, can be compatible with this material for building purposes. The article presents the validation of a 3D printing system for construction applications and the evaluation of soil-cement matrices' printability. First, the paper defines the printing parameters through experimental testing on soil matrices. Then, the article evaluates the printability of soil-cement matrices through filament printing and stacking tests. The results show that the 3D printing system prototype can fabricate small and medium-sized elements with soil matrices after correctly defining the pumping speed, printing speed, and layer height. Furthermore, experimental printing test results demonstrate that soil-cement matrices can be easily extruded and stacked; however, their printability capacity is strongly affected by the total water content and printing speed. This research highlights the suitability of soil-cement mixtures for additive manufacturing, a promising outcome that can facilitate the construction of homes in remote areas using 3D printing systems.

Abstract: The construction industry is a service sector that is often faced uncertain circumstances with a high rate of changes in its project operations. These changes not only often occur in the implementation (build) phase of a construction project, but it also happens in the planning (design) phase. In general, dealing with such uncertain circumstances means to have the possibility for failure in achieving the goals of a project. Even though changes and adjustments are common in this sector, it nevertheless will bring risks to the construction works. For example, the time, costs, and quality. Hence, a preventive system is needed with which can minimise the risks that may arise during the project activities. The objective of this research is to identify the caused factors of the risks on the construction business, and that to further suggest the applicable model as the preventive action of the risks. This study began with a detail review to seven risk indicators; Labour Risk (X₁), Contractual Risk (X₂), Human Resources Risk (X₃), Design and Technology Risk (X₄), Material and Tool Risk (X₅), Implementation Risk (X₆), and Force Majeure Risk (X₇). This research was developed further using questionnaires and expert validation as the primary data, which furthermore analysed using analysis factors, descriptive analysis, and probability impact matric in order to determine the level of the risks. The risk level analysis resulted three variables as the top event (dominant risk), which are X₁, X₃ and X₄. These findings were then advanced following Bowtie diagram and scenario analysis, hence suggested a modelling that described possible preventive and corrective strategies. Both the Bowtie diagram and scenario analysis are not only helpful as the guidance and warning, but also practical for the construction practitioners in managing the risk management and decision making for the construction project.

Abstract: Construction projects are typically carried out under high-risk conditions and managers are forced to handle a great deal of uncertainty during the construction process. The Earned-Value Analysis is a control technique that provides early warnings of performance by quantitative measures, enabling timely corrective actions to ensure project success. This method was developed to control and adjust the project's baseline during execution. The objective of this article is to discuss the main implications of using EVA in construction projects through a case study. Results proved the applicability of the method in the construction industry. The various indicators generated allow managers to make forecasts for optimistic, realistic, and pessimistic scenarios, having the opportunity to correct any deviations in advance. In addition to forecasts, benchmarking data can be generated for the planners or companies responsible for the project, thus increasing the accuracy of future projects.

Abstract: The recycling of construction and demolition waste (CDW) is currently of growing interest. Starting from such waste products it’s possible to produce recycled aggregates for construction purposes providing environmental and economic advantages. Life-cycle assessment (LCA) is a valuable tool to evaluate the environmental impact at end of life of CDW and improve the employment of recycled aggregates in concrete. In this research a life cycle evaluation of concrete mixtures made with CDW is performed to assess their environmental impacts considering various scenarios related to recycling sites with different conveying distances. The advantages of replacing natural aggregates with recycled ones are evaluated using a combination of LCA model and Life-Cycle Impact Assessment to estimate the environmental effects for all the considered scenarios. The results highlighted the highest environmental impact for the scenario with total landfill as well as an increasing impact for increasing distance from the demolition site.

Abstract: Non-observance of the heat and humidity regime in buildings can lead to significant problems such as the formation of condensation on the internal surfaces of the enclosing structures, which not only destroys the construction of the building but also leads to the formation of mould, fungi that are dangerous for human life and health. In addition, the use of construction or thermal insulation materials in a humid environment increases the energy consumption as a result of which the building's energy efficiency is reduced. In this paper considered the impact of the heat and humidity regime on the construction and thermal insulation materials, and also presents a developed new structure of an air dryer dehumidifier. The results of the study showed that an increase in the moisture content of the construction material by 10%, the thermal conductivity of the material increases from 6% to 60%, which will significantly increase the heating and cooling demand of the building. The developed new structure of the air dehumidifier reduces the humidity of the air, without using additional equipment, or substance such as refrigerant or absorbent. The proposed device significantly reduces capital and operating costs.

Abstract: Bamboo construction is often related to traditional and vernacular architecture, which is found mostly in rural areas, where, for the construction, local people apply diverse techniques learned in an empirical way and passed on from generation to generation. However, in the last years, many modern constructions with bamboo have been developed around the world. At the same time, many connections have been designed for permanent and ephemerals lightweight structures. However, most of them do not have standardization and mechanical testing, because it is expensive or there are no means to do it. Therefore, it is required to create a technology classification for the most used existing connections, starting with the traditional way to join canes until the contemporary connections developed with high technology. In this context, connections are a challenge to be developed, as currently there is no normative in bamboo to follow and create standardization.

Abstract: The building construction industry is slowly adopting bio-based materials. To accelerate this process, it is necessary to gain more proven data about technical issues. This should also fit in the social-economical and juridical context of the construction industry. In this paper we will highlight the main drivers and research that is going on in the Netherlands. Including a cross border project that works on this topic.

Abstract: Recently, the construction industry uses the Recycled Concrete Aggregates (RCA)resulting from construction and demolition waste (CDW) to achieve sustainable requirements andeconomic benefits. In this paper, asphalt paving mixes were prepared with RCA instead of naturalaggregates for the base course in flexible road pavements and walking areas used by pedestrians andcyclists. Different asphalt mixes samples were prepared with different asphalt contents to meet therequired specifications. Additionally, several laboratory tests were carried out to assess mixturebehavior including the Marshall test. The results indicated that the mixture made with aggregates ofCDW have met all the requirements of Iraqi specifications of roads and bridges (SORB/R9). Thisinvestigation could be a useful guide for road engineers in designing asphalt mixtures from RCA.