scholarly journals A Review on the Performance of Concrete Containing Non-Potable Water

2021 ◽  
Vol 11 (15) ◽  
pp. 6729
Author(s):  
Babar Ali ◽  
Rawaz Kurda ◽  
Jorge de Brito ◽  
Rayed Alyousef
Keyword(s):  
Construction Industry ◽  
Potable Water ◽  
Water Footprint ◽  
State Of The Art ◽  
Construction Materials ◽  
Negative Effects ◽  
Different Types ◽  
Hardened State ◽  
Technical Properties ◽  
Industrial Sewage

Construction industries consume huge amounts of potable water during activities such as washing of aggregates, stone crushing, manufacturing, and curing of concrete, mortars, grouts, and wetting of masonry bricks. It is also responsible for wastewater generated during the finishing and cleaning of buildings and construction equipment. Therefore, the water-footprint of construction industry cannot be ignored to reach the state-of-the art sustainability. This study reviewed the technical properties of construction materials made with non-potable water (NPW), i.e., domestic and industrial sewage. The study identified the positive and negative effects of non-potable water on the fresh- and hardened-state properties of concrete. This study also identified the gaps in the literature that can be analysed in order to produce reliable information related to the use of different types of NPW on the properties of concrete.

scholarly journals Holistic modelling approach for special concrete: from fresh- to hardened-state

2019 ◽  
Vol 3 ◽  
pp. 84-90 ◽  
Author(s):  
Sergio H.P. Cavalaro ◽  
Ana Blanco ◽  
Ricardo Pieralisi
Keyword(s):  
Construction Industry ◽  
Construction Materials ◽  
Production Processes ◽  
Modelling Strategies ◽  
Hardened State ◽  
Holistic Design ◽  
Precautionary Measures ◽  
Metallic Parts ◽  
Long Term Performance ◽  
Term Performance

In the construction industry, the design of dimensions and material properties is generally separated from the design of material composition and of the production processes used. Such divide is enabled by robust construction materials (like concrete) little affected by production processes if minimum precautionary measures are in place. The same does not hold true for special concrete types; whose higher sensibility compels a shift towards more comprehensive approaches that assimilate the production process in a holistic design. The design driven by integrated numerical simulations encompassing from production to the long-term performance is already ordinary in the manufacturing of plastic and metallic parts. Nevertheless, it remains an alien to the construction industry. The objective of this paper is to review existing studies that might underpin this holistic design approach in construction and show some of its capabilities. Advanced modelling strategies available to simulate the behaviour from the fresh- to the hardened-state are discussed for the cases of pervious concrete and fibre reinforced concrete. This approach provides a deeper insight about the material behaviour and aids to a new level of numerical optimisation of their compositions and production processes, unlocking a potential transformation of the modus operandi of the construction industry.

scholarly journals A Review on Self Compacting Concrete with Cementitious Materials and Fibers

2018 ◽  
Vol 8 (3) ◽  
pp. 2969-2974 ◽  
Author(s):  
N. A. Memon ◽  
M. A. Memon ◽  
N. A. Lakho ◽  
F. A. Memon ◽  
M. A. Keerio ◽  
...  
Keyword(s):  
Construction Industry ◽  
Cement Content ◽  
Developed Countries ◽  
Cementitious Materials ◽  
Normal Concrete ◽  
Conventional Concrete ◽  
Cement Replacement ◽  
Different Types ◽  
Construction Activity ◽  
Hardened State

Self-compacted concrete (SCC) is cast in the formwork without compaction and it fulfills the formwork due to its own weight. SCC is considered to have many advantages in comparison with conventional concrete like improved construction quality, faster construction activity, reduced cost etc. SCC is produced with the same ingredients of normal concrete. However, cementitious materials are also adopted to replace the cement content in SCC in order to use waste materials from industries and agricultural products. To further enhance the performance of SCC, different types of fibers are tried in order to produce fiber reinforced SCC. The fibers in the concrete bridge the cracks and diffuse the crack propagation which improves mechanical properties. In developed countries SCC has reasonable acceptance in construction industry but in developing countries like Pakistan has not gained acceptance. This paper is focused on undertaking a review of SCC with cement replacement and fiber reinforcement materials. The main objective of this paper is to compile the literature in order to understand the various properties of SCC in fresh and hardened state when these cement replacement materials and fibers are used.

scholarly journals Turning trash into an asset: a case study of prince sultan university campus waste

2020 ◽  
Vol 167 ◽  
pp. 06003
Author(s):  
Shabir Hussain Khahro ◽  
Tauha Hussain Ali ◽  
Zubair Ahmed Memon ◽  
Amjad Ali Panhwar ◽  
Anas Haribat
Keyword(s):  
Tensile Strength ◽  
Natural Resources ◽  
Construction Industry ◽  
Commercial Product ◽  
University Campus ◽  
Rapid Urbanization ◽  
Different Types ◽  
Compressive Loads ◽  
Hardened State

Concrete is one of the key material used in the construction industry. Concrete is used as a compressive material and it is also reinforced by rebar’s to improve its tensile strength. Due to rapid urbanization concrete use is getting huge demand and it became a major business industry. Whereas, it also utilizes natural resources to the same hasty level. Therefore, this paper utilizes waste tissues of a university as an aggregate replacer. The different test was performed in a green and hardened state. It is observed that the new concrete is good in workability and it has normal temperature but it is not good at resisting higher compressive loads. Similarly, the waste material collected after the tests and utilized in making a commercial product. This paper aims to save the environment by utilizing different types of waste in making useful items to save resources.

scholarly journals The Effects of Recyling on Economy: The Case of Usage of Scrapped Tires in Construction Industry

2016 ◽  
Author(s):  
Hümeyra Tosun ◽  
Fatih Kürşat Fırat
Keyword(s):  
Construction Industry ◽  
National Economy ◽  
Capital Expenditure ◽  
Construction Materials ◽  
Raw Material ◽  
World Population ◽  
Positive Contribution ◽  
Negative Effects ◽  
Economic Contribution ◽  
Materials Recycling

Today, rapidly industrialization and an accompanying increase of the world population cause diminishing of the limited amount of natural resources. The purpose of this study is to examine the recycling applications in the construction industry and to investigate the contribution of scrapped tires to construction industry and national economy. The construction industry is one of the fields that has the largest raw material consumption. Due to the high demand for the construction materials recycling is often employed and provide a significant economic contribution. Today, scrapped tires both exist abundantly and are currently worthless wastes. This wastes not only pollute the environment but also cause negative effects on the human healthy. Because of this reason, old tires are either reduced to certain dimension or melted in the recycling plants. The new products that therefore emerges is added in to the hot mix asphalt and then used in highway constructions, which are a significant capital expenditure for the national economy. As a result of this study, it is reveal that recycling in the construction industry has very significant positive contribution to natural environment and the existing recycling resources are not well-utilized. Moreover, the applications that have been done so far provided significant contributions to the national economy. Consequently, recycling studies should be speeded up and governmental supports should be put into practice.

scholarly journals Waste-Based One-Part Alkali Activated Materials

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 2911
Author(s):  
Margarida Gonçalves ◽  
Inês Silveirinha Vilarinho ◽  
Marinélia Capela ◽  
Ana Caetano ◽  
Rui Miguel Novais ◽  
...  
Keyword(s):  
Compressive Strength ◽  
Microstructural Analysis ◽  
Construction Materials ◽  
Sodium Metasilicate ◽  
High Compressive Strength ◽  
Hardened State ◽  
First Time ◽  
Furnace Slag ◽  
Alkali Activated

Ordinary Portland Cement is the most widely used binder in the construction sector; however, a very high carbon footprint is associated with its production process. Consequently, more sustainable alternative construction materials are being investigated, namely, one-part alkali activated materials (AAMs). In this work, waste-based one-part AAMs binders were developed using only a blast furnace slag, as the solid precursor, and sodium metasilicate, as the solid activator. For the first time, mortars in which the commercial sand was replaced by two exhausted sands from biomass boilers (CA and CT) were developed. Firstly, the characterization of the slag and sands (aggregates) was performed. After, the AAMs fresh and hardened state properties were evaluated, being the characterization complemented by FTIR and microstructural analysis. The binder and the mortars prepared with commercial sand presented high compressive strength values after 28 days of curing-56 MPa and 79 MPa, respectively. The mortars developed with exhausted sands exhibit outstanding compressive strength values, 86 and 70 MPa for CT and CA, respectively, and the other material’s properties were not affected. Consequently, this work proved that high compressive strength waste-based one-part AAMs mortars can be produced and that it is feasible to use another waste as aggregate in the mortar’s formulations: the exhausted sands from biomass boilers.

scholarly journals Investigations of Museum Indoor Microclimate and Air Quality. Case Study from Romania

Atmosphere ◽  
2021 ◽  
Vol 12 (2) ◽  
pp. 286
Author(s):  
Dorina Camelia Ilieș ◽  
Florin Marcu ◽  
Tudor Caciora ◽  
Liliana Indrie ◽  
Alexandru Ilieș ◽  
...  
Keyword(s):  
Air Quality ◽  
Volatile Organic Compounds ◽  
Organic Compounds ◽  
Construction Materials ◽  
International Standards ◽  
Total Volatile ◽  
Negative Effects ◽  
Museum Exhibits ◽  
Volatile Organic ◽  
Total Volatile Organic Compounds

Poor air quality inside museums is one of the main causes influencing the state of conservation of exhibits. Even if they are mostly placed in a controlled environment because of their construction materials, the exhibits can be very vulnerable to the influence of the internal microclimate. As a consequence, museum exhibits must be protected from potential negative effects. In order to prevent and stop the process of damage of the exhibits, monitoring the main parameters of the microclimate (especially temperature, humidity, and brightness) and keeping them in strict values is extremely important. The present study refers to the investigations and analysis of air quality inside a museum, located in a heritage building, from Romania. The paper focuses on monitoring and analysing temperature of air and walls, relative humidity (RH), CO2, brightness and particulate matters (PM), formaldehyde (HCHO), and total volatile organic compounds (TVOC). The monitoring was carried out in the Summer–Autumn 2020 Campaign, in two different exhibition areas (first floor and basement) and the main warehouse where the exhibits are kept and restored. The analyses aimed both at highlighting the hazard induced by the poor air quality inside the museum that the exhibits face. The results show that this environment is potentially harmful to both exposed items and people. Therefore, the number of days in which the ideal conditions in terms of temperature and RH are met are quite few, the concentration of suspended particles, formaldehyde, and total volatile organic compounds often exceed the limit allowed by the international standards in force. The results represent the basis for the development and implementation of strategies for long-term conservation of exhibits and to ensure a clean environment for employees, restorers, and visitors.

scholarly journals Multiple objects tracking in the UAV system based on hierarchical deep high-resolution network

2021 ◽  
Author(s):  
Wei Huang ◽  
Xiaoshu Zhou ◽  
Mingchao Dong ◽  
Huaiyu Xu
Keyword(s):  
High Resolution ◽  
Object Tracking ◽  
High Performance ◽  
State Of The Art ◽  
Class Imbalance ◽  
Unified Framework ◽  
Multiple Objects ◽  
Tracking Process ◽  
Objects Tracking ◽  
Different Types

AbstractRobust and high-performance visual multi-object tracking is a big challenge in computer vision, especially in a drone scenario. In this paper, an online Multi-Object Tracking (MOT) approach in the UAV system is proposed to handle small target detections and class imbalance challenges, which integrates the merits of deep high-resolution representation network and data association method in a unified framework. Specifically, while applying tracking-by-detection architecture to our tracking framework, a Hierarchical Deep High-resolution network (HDHNet) is proposed, which encourages the model to handle different types and scales of targets, and extract more effective and comprehensive features during online learning. After that, the extracted features are fed into different prediction networks for interesting targets recognition. Besides, an adjustable fusion loss function is proposed by combining focal loss and GIoU loss to solve the problems of class imbalance and hard samples. During the tracking process, these detection results are applied to an improved DeepSORT MOT algorithm in each frame, which is available to make full use of the target appearance features to match one by one on a practical basis. The experimental results on the VisDrone2019 MOT benchmark show that the proposed UAV MOT system achieves the highest accuracy and the best robustness compared with state-of-the-art methods.

scholarly journals Fighting Together against the Pandemic: Learning Multiple Models on Tomography Images for COVID-19 Diagnosis

AI ◽  
2021 ◽  
Vol 2 (2) ◽  
pp. 261-273
Author(s):  
Mario Manzo ◽  
Simone Pellino
Keyword(s):  
Network Architecture ◽  
State Of The Art ◽  
Ensemble Classification ◽  
Effective Vaccine ◽  
Rt Pcr ◽  
Neural Network Architecture ◽  
Experimental Phase ◽  
Different Types ◽  
Polymerase Chain ◽  
Better Than

COVID-19 has been a great challenge for humanity since the year 2020. The whole world has made a huge effort to find an effective vaccine in order to save those not yet infected. The alternative solution is early diagnosis, carried out through real-time polymerase chain reaction (RT-PCR) tests or thorax Computer Tomography (CT) scan images. Deep learning algorithms, specifically convolutional neural networks, represent a methodology for image analysis. They optimize the classification design task, which is essential for an automatic approach with different types of images, including medical. In this paper, we adopt a pretrained deep convolutional neural network architecture in order to diagnose COVID-19 disease from CT images. Our idea is inspired by what the whole of humanity is achieving, as the set of multiple contributions is better than any single one for the fight against the pandemic. First, we adapt, and subsequently retrain for our assumption, some neural architectures that have been adopted in other application domains. Secondly, we combine the knowledge extracted from images by the neural architectures in an ensemble classification context. Our experimental phase is performed on a CT image dataset, and the results obtained show the effectiveness of the proposed approach with respect to the state-of-the-art competitors.

scholarly journals Cements with calcareous fly ash as component of low clinker eco-self compacting concrete

2019 ◽  
Vol 9 (1) ◽  
pp. 196-201
Author(s):  
Jacek Gołaszewski ◽  
Grzegorz Cygan ◽  
Tomasz Ponikiewski ◽  
Małgorzata Gołaszewska
Keyword(s):  
Fly Ash ◽  
Hardened Concrete ◽  
Self Compacting Concrete ◽  
Basic Properties ◽  
Ecological Self ◽  
Different Types ◽  
Hardened State ◽  
Main Component ◽  
New Generation ◽  
Good Workability

AbstractThe main goal of the presented research was to verify the possibility of obtaining ecological self-compacting concrete of low hardening temperature, containing different types of cements with calcareous fly ash W as main component and the influence of these cements on basic properties of fresh and hardened concrete. Cements CEM II containing calcareous fly ash W make it possible to obtain self-compacting concrete (SCC) with similar initial flowability to analogous mixtures with reference cement CEM I and CEM III/B, and slightly higher, but still acceptable, flowability loss. Properties of hardened concretes with these cements are similar in comparison to CEM I and CEM III concretes. By using cement nonstandard, new generation multi-component cement CEM “X”/A (S-W), self-compacting concrete was obtained with good workability and properties in hardened state.

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