Papers by Keyword: Civil Engineering

Abstract: After researching and analyzing existing deformation sensors, their several key features were identified. These features highlight, on one hand, important considerations for the development of new deformation sensors, and on the other hand, potential strategies for addressing the limitations that hinder the performance or applicability of current sensors—particularly in terms of accuracy and range of use. This paper explores both the design of a next-generation deformation sensor and the enhancement of existing transducers. Specifically, we introduce an optical deformation transducer capable of measuring the deformation of objects without being restricted by their material composition or size. The sensor’s measurements are minimally influenced by environmental factors, offering greater reliability. Additionally, the sensor is cost-effective, simple to manufacture, and easy to install.

Abstract: As bridge structures have advanced, the demand for higher bearing capacity has increased. Castable Polyurethane Elastomeric Bearings have gained attention due to their strong load-bearing capacity and straightforward manufacturing process. This paper focuses on the development of a polyurethane seismic isolation bearing and examines its microscopic and mechanical properties. Additionally, a flexible strain sensor was created using polyurethane as the polymer substrate and multi-walled carbon nanotubes (MWCNT) as the conductive particles. The sensor's force-electric sensing behavior was systematically analyzed, and its effectiveness in monitoring the deformation of laminated isolation bearings was verified.

Abstract: The substantial increases in bitumen pricing due to increasing in demand for petroleum derived products in line with decreasing world crude resources has suggested that all industries, including the asphalt pavement industry, should be exploring economically, socially, and environmentally sustainable approaches either to enhance the performance of asphalt mixture using some recycled materials or developing eco-friendly asphalt mixture. The current study presents new development of eco-friendly bio-oil-bitumen produced using some local materials. Two bitumen sources 40-50 Pen were used, Dora and Nasiriyah, obtained from Dora and Nasiriyah refineries. Waste cooking oil was collected from local households and cafeterias without financial cost. Methanol, Sulfuric acid (as a catalyst), and Zeolite were considered in the development process. Initial results highlighted that the modified bio-oil-bitumen has shown superior performance compared to that of traditional bitumen. The current successful development has an encouragement to further characterization of such production.

Abstract: The main goal of this work is the analysis of the thermal and environmental benefits of 3D printing on building construction. Present literature reports a considerable number of benefits for 3D printing, namely reduction of material use, lower operational costs and time saving. Authors also mention design freedom, higher efficiency, productivity and quality. This work presents the most important advances in 3D printing in civil engineering, specifically, a critical review of the thermal and environmental benefits of 3D printing on building construction. The limitations of construction 3D printing with focus on large-scale applications, technology costs, mix development and optimisation and thermal behaviour will be, also, defined.

Abstract: The future of construction will be directly connected with additive manufacturing (AM). It is easy to see the lack of consistency between jobs, labour inefficiency, schedule delays, delays on material delivery, exceeding budget projections and high percentage of material waste. Over the years, additive manufacturing has been a constant topic of discussion, in order to understand the limitations, applications and the overall impact on the cost of construction. In this work it is intended to present/discuss opportunities and challenges and the potential of AM to revolutionize the industry.

Abstract: Due to the large number of stainless steels with different chemical composition and different microstructure the selection of the suitable material represents a huge challenge. In order to facilitate the appropriate grade selection, in the current European standard EN 1993-1-4 a procedure is defined based on the use of a look-up table considering the key variables that influence the selection of stainless steels. The table uses descriptions that competent designers should be able to readily understand or define without prior knowledge. The output from the look-up table is used to select alloys based on a Corrosion Resistance Class (CRC) from I to V. The advantage of this approach is that the designer simply specifies the relevant CRC and does not need to consider in detail which of the many (very similar) alloys to specify.

Abstract: An extensive experimental work of instrumented indentation on isolated particles of Non-Hazardous Waste Incineration bottom ash (NHWI) is presented in this paper. The aggregates studied come from the Garenne quarries at Vignoc (Brittany, France). Two spherical tungsten carbide indenters of respective 0.5 and 140 mm radius “R” were used for test series “A” and “B”. The particles studied have diameters ranging between 20 and 25 mm. With a 0.5 mm radius indenter, average reduced elastic moduli ranging from 15 to 68 GPa were found. An average reduced elastic modulus of 15 GPa was found with the 140 mm radius indenter. The experiments made it possible to highlight the particular heterogeneity that characterizes the rigidity of the types of aggregates studied.

Abstract: The production of low-temperature clay lightweight aggregates is pursued eagerly as low energy and cost lightweight aggregate concrete (LAC) building blocks becomes more popular. Clay ceramic hollow spheres (CCHS) with waste glass (WG) additive was developed and studied as aggregate in cement composite. CCHS with diameter ranging in 6/8mm were produced by a sacrificial template technique with subsequent sintering under temperature of 900 °C and different WG content of 0, 5, 7 and 10 wt%. The effect of the sintering temperature and WG content on the physical properties and morphology of the CHS-cement composites were studied by means of optical microscopy and mechanical properties. Obtained composite materials were compared with commercially available lightweight fillers such as foamed glass granules and lightweight expanded clay aggregates (LECA). The results compressive strength of CCHS containing LAC is much higher from 4.8 to 7.1 MPa in comparison with the LECA-cement LAC - 3.5 MPa. Reduction of CCHS open porosity due to higher content of WG (10%) leads to lower absorption of cement paste, as result lower cement consumption, lower bulk density and compression strength. LAC with CCHS proved to be promising construction material due to low-temperature production process (i), widely available raw material (clay) and secondary material (glass cullet) use (ii), reduction of cement paste needed for material production (iii).

Abstract: This paper shows the results of a project that investigated the humidity of the air in the ventilation gap of a green façade system. The systems which were investigated are made of aluminium troughs, aluminium modules, or fleece. These systems are mounted on metal rails. The metal rails connect the façade with the plants. This creates a curtain façade that is ventilated by air. The humidity of the air in the gap was investigated, and this paper shows the results of the investigation.

Abstract: Sandwich foam beams, made of solid skins and aluminium foam core, are usually applied in high-tech engineering field while they are not yet adopted in civil structures. An initial, explorative study on the structural application of metal foam is presented in this paper. The potentials of sandwich foam beams are studied through analytical models and parametric analyses; the sensitivity of the flexural response of the media to the total amount of pores and their spatial distribution are investigated. An analytical tool able to design functionally graded beams of metallic foam is presented and applied with reference some commercial aluminium foams. An experimental campaign is being planned to validate the presented results.