scholarly journals Applicability of using the 3D concrete printing technology in Sudan

2021 ◽  
Vol 9 (2) ◽  
pp. 64-70
Author(s):  
Ruaa Elnaeem ◽  
Mohammed Taglsir
Keyword(s):  
Low Cost ◽  
Three Dimensional ◽  
Sand Mixture ◽  
Housing Projects ◽  
Construction Methods ◽  
Concrete Mixtures ◽  
Complex Shapes ◽  
Low Cost Housing ◽  
Materials Used ◽  
The Cost

Three-dimensional (3D) Printing is an advanced manufacturing process that has been applied to many fields. Recently, the 3D Concrete Printing (3DCP) has been employed for construction due to its ability to produce complex shapes easily, with less human intervention and with minimum material wastage. However, there are challenging issues regarding the cost of construction and the components of concrete mixture which are not fully explored. The aim of this paper is to review the 3DCP technology and investigate the possibility of applying it in Sudan, specifically for low-cost housing. In order to meet this aim, a comprehensive review has been done to study the projects implemented worldwide using 3DCP technique. Then, some concrete mixtures have been reviewed analyze the amount of materials used in each mix. The necessary tests to ensure the, workability, Extrudability and buildability have also been specified. Then the 3DCP technique has been compared with three common construction methods in Sudan for low-cost housing those were 40 square meters area in plan. These methods are the cement blocks, the Ferrocement and the graded sand mixture.. The comparison has been made in terms of construction cost, construction duration and the man-force required. The results have shown that the 3DCP model needed the least number of construction days. However, it was the highest in terms of the cost and the second best in terms of the used labors. It has been concluded that applying 3DCP technology in Sudan is possible and could be effective in the low-cost housing projects.  

A Very Low-Cost, Labor-Efficient, and Simple Method to Block Scattered Ultraviolet Light in PDMS Microfluidic Devices by Inserting Aluminum Foil Strips

2018 ◽  
Vol 11 (1) ◽  
Author(s):  
Shuo Wang ◽  
Peter Shankles ◽  
Scott Retterer ◽  
Yong Tae Kang ◽  
Chang Kyoung Choi
Keyword(s):  
Soft Lithography ◽  
Uv Light ◽  
Low Cost ◽  
Microfluidic Devices ◽  
Aluminum Foil ◽  
Material Synthesis ◽  
Simple Method ◽  
Micro Particles ◽  
Complex Shapes ◽  
The Cost

Abstract Opto-microfluidic methods have advantages for manufacturing complex shapes or structures of micro particles/hydrogels. Most of these microfluidic devices are made of polydimethylsiloxane (PDMS) by soft lithography because of its flexibility of designing and manufacturing. However, PDMS scatters ultraviolet (UV) light, which polymerizes the photocrosslinkable materials at undesirable locations and clogs the microfluidic devices. A fluorescent dye has previously been employed to absorb the scattered UV light and shift its wavelength to effectively solve this issue. However, this method is limited due to the cost of the materials (tens of dollars per microchip), the time consumed on synthesizing the fluorescent material and verifying its quality (two to three days). More importantly, significant expertise on material synthesis and characterization is required for users of the opto-microfluidic technique. The cost of preliminary testing on multiple iterations of different microfluidic chip designs would also be excessive. Alternatively, with a delicate microchannel design, we simply inserted aluminum foil strips (AFS) inside the PDMS device to block the scattered UV light. By using this method, the UV light was limited to the exposure region so that the opto-microfluidic device could consistently generate microgels longer than 6 h. This is a nearly cost- and labor-free method to solve this issue.

scholarly journals Part of the Solution

2010 ◽  
Vol 132 (01) ◽  
pp. 46-49 ◽  
Author(s):  
Jean Thilmany
Keyword(s):  
United States ◽  
Rapid Prototyping ◽  
Affordable Housing ◽  
Low Cost ◽  
The United States ◽  
Industrialized Countries ◽  
Construction Methods ◽  
Emergency Housing ◽  
Low Cost Housing ◽  
New Buildings

This article presents numerous examples of rapid prototyping applications in the United States and explains its benefits. Constructing housing via rapid prototyping methods is expected to save time and money and bring affordable and environmentally friendly housing to people in need. Using an additive-manufacturing technique for constructing new buildings could provide emergency housing for victims of disasters. The technique could also be used for affordable housing for those in the United States or in third-world countries, or for creating new housing styles that bring curved, organic designs rather than straight surfaces to the homes. In industrialized countries, automating the manufacturing of products such as shoes or cars can cut costs about 25% as compared to manual construction methods. Makers of rapid prototyping technology are using CT scans to create exact-fit implants for craniofacial and maxillofacial operations. The rapid prototyping process is also being matched with humanitarian efforts in another project, this one situated in war-torn Iraq. Analysts suggest that custom medical devices and low-cost housing—affordable for everyone and quick to manufacture accurately—will help grow rapid prototyping into a robust industry.

scholarly journals ASSESSING THE ACCURACY AND PRECISION OF IMPERFECT POINT CLOUDS FOR 3D INDOOR MAPPING AND MODELING

2018 ◽  
Vol IV-4/W6 ◽  
pp. 3-10
Author(s):  
J. Chen ◽  
O. E. Mora ◽  
K. C. Clarke
Keyword(s):  
Low Cost ◽  
Random Noise ◽  
Three Dimensional ◽  
Laser Scanner ◽  
Point Clouds ◽  
Accuracy And Precision ◽  
Wide Range ◽  
Sharp Edges ◽  
The Cost ◽  
Indoor Spaces

<p><strong>Abstract.</strong> In recent years, growing public interest in three-dimensional technology has led to the emergence of affordable platforms that can capture 3D scenes for use in a wide range of consumer applications. These platforms are often widely available, inexpensive, and can potentially find dual use in taking measurements of indoor spaces for creating indoor maps. Their affordability, however, usually comes at the cost of reduced accuracy and precision, which becomes more apparent when these instruments are pushed to their limits to scan an entire room. The point cloud measurements they produce often exhibit systematic drift and random noise that can make performing comparisons with accurate data difficult, akin to trying to compare a fuzzy trapezoid to a perfect square with sharp edges. This paper outlines a process for assessing the accuracy and precision of these imperfect point clouds in the context of indoor mapping by integrating techniques such as the extended Gaussian image, iterative closest point registration, and histogram thresholding. A case study is provided at the end to demonstrate use of this process for evaluating the performance of the Scanse Sweep 3D, an ultra-low cost panoramic laser scanner.</p>

scholarly journals An Experimental Study on Eco-Friendly and Cost-Effective Natural Materials for Productivity Enhancemento Single Slope Solar Still

2021 ◽  
Author(s):  
SENDHIL KUMAR NATARAJAN ◽  
Subbarama Kousik Suraparaju ◽  
Rajvikram Madurai Elavarasan ◽  
Rishi Pugazhendhi ◽  
Eklas Hossain
Keyword(s):  
Rice Straw ◽  
Evaporation Rate ◽  
Low Cost ◽  
Cost Effective ◽  
Solar Still ◽  
Condensation Rate ◽  
Evaporation And Condensation ◽  
Glass Cover ◽  
Materials Used ◽  
The Cost

Abstract The proposed research study aims to improve the productivity of solar still (SS) by using low-cost and eco-friendly materials. The aforementioned objective was achieved by enhancing the evaporation rate of seawater in the absorber basin and the condensation rate over the glass cover of the solar still. In this study, the low-cost and eco-friendly materials used for enhancing the evaporation rate in the solar still were Molasses Powder (MP), Sawdust (SD), Rise Husk (RH). In addition to these materials, Bamboo Straw (BS), Banana Leaf stem (BL), and Rice Straw (RS) were used as absorbing materials over the glass cover for enhancing the condensation rate. The experiments were carried out under similar meteorological conditions and the results of the modified solar still were compared with Conventional Solar Still (CSS). The productivities of CSS, SSMP, SSRH, SSSD, SSBS, SSBL and SSRS were about 2250 mL/m2, 2383 mL/m2, 2467 mL/m2, 3033 mL/m2, 2700 mL/m2, 2683 mL/m2, and 3367 mL/m2 , respectively. The results of the experimental investigation highlighted that the SSSD had a comparatively better evaporation rate and 34.81% higher yield than CSS. Besides, SSRS had a comparatively better condensation rate and a 51.88% higher yield than CSS. Later, the combination of sawdust (SD) and rice straw (RS) was investigated for combined enhancement of evaporation and condensation. The solar still with sawdust and rice straw (SSSDRS) showed a 62.88% improvement in productivity with 3633 mL/m2 when compared to CSS. Also, the economic analysis showed that the cost per litre (CPL) of freshwater obtained from SSSDRS was about ₹ 1.9 ($ 0.025) with a payback period of 4.4 months which was the least when compared to all the considered cases.

A study on materials used for low cost housing construction in India

2021 ◽  
Author(s):  
M. P. Thiyaneswaran ◽  
K. Jeevitha Pranusha ◽  
L. Bala Krishnan ◽  
N. Kiran Raj
Keyword(s):  
Low Cost ◽  
Housing Construction ◽  
Low Cost Housing ◽  
Materials Used

Properties of Compressed Interlock Earth Blocks Manufactured from Locally Available Lateritic Soil for Low Cost Housing Projects

2021 ◽  
Vol 39 ◽  
pp. 85-93
Author(s):  
Dissanayake Dmdok
Keyword(s):  
Compressive Strength ◽  
Construction Industry ◽  
Cement Content ◽  
Low Cost ◽  
Soil Samples ◽  
Lateritic Soil ◽  
Housing Projects ◽  
Earth Blocks ◽  
Low Cost Housing ◽  
Compaction Ratio

This investigation was carried out to identify the engineering properties of compressed interlock earth blocks manufactured from locally available lateritic soil and introduce to use the manufactured soil blocks to minimize the material and finishing cost for the low cost housing projects. The soil samples used in this study were well-graded lateritic sandy soil which has the composition of 1.9% gravel, 94% sand and 4.1% silt / clay. These soil samples were passed through the 100-mesh sieve and mixed with ordinary Portland cement to prepare the admixture. While compressing through a hydraulics jack by varying the compositions and the volume of soil-cement admixtures, compaction soil blocks were manufactured in a locally fabricated 250 mm x125 mm x100 mm standard steel mould. The manufactured soil blocks allowed to cure while spraying small quantity of water and covering with polythene for 28 days. Average compressive strengths of soil blocks made with 5% cement with 1.6:1 and 1.8:1 volume compactions were 1.3 Mpa and 1.9 Mpa, respectively. However, both compressive strength values were less than the standard limits of 2.8 MPa stated in SLS 1382:2009, local standards for soil blocks used for construction industry. However, soil blocks made with 10% cement under same compaction ratios attained compressive strengths of 3.0 MPa and 3.6 MPa respectively and it is above the required standards limits. However, 15% and 20% cement containing earth blocks have much higher compressive strengths but increase the cost of production. Regression analysis results confirmed the strong correlation between cement content and the compressive strength of the soil bricks. The soil bricks manufactured with more than 12.06% cement soil mix by maintaining compaction ratio into 1.6:1 or Soil bricks manufactured with more than 5.16% cement mix by maintaining compaction ratio into 1.8:1 will produce standards soil bricks for construction industry and these results further confirmed that wet and dry compressive strength of soil bricks will increase with increasing the compaction ratio and the cement content. However, when considering the compressive strength, water absorption level and cost effectiveness, soil bricks manufactured by maintaining compaction ratio into 1.8:1 with more than 5.16% cement mix will produce required standards cost effective soil bricks for construction industry.

scholarly journals Identification of Schedule-Performance Indicators and Delay-Recovery Strategies for Low-Cost Housing Projects

2019 ◽  
Vol 11 (21) ◽  
pp. 6005 ◽  
Author(s):  
Elnaz Safapour ◽  
Sharareh Kermanshachi ◽  
Bahaa Alfasi ◽  
Reza Akhavian
Keyword(s):  
Low Income ◽  
Construction Projects ◽  
Low Cost ◽  
Design And Technology ◽  
Resource Location ◽  
Cost Overruns ◽  
Housing Projects ◽  
Schedule Delay ◽  
Low Cost Housing ◽  
Schedule Performance

Many construction projects suffer from schedule delays that ultimately lead to considerable cost overruns and defeat the purpose of low-cost housing (LCH), which is to support low-income earners. It is, therefore, vital that the schedule delays and cost overruns be minimized. The objectives of this research were to investigate, identify, and classify the schedule-delay indicators (SDIs), prioritize them based on their level of impact, and formulate constructive strategies to improve the schedule performance. To achieve the objectives set forth, 68 interviews were conducted with professionals who are active in LCH projects, and a structured survey was developed and distributed to other experts involved in LCH projects to validate the result of the interviews and collect additional data. Survey responses were collected from 101 individuals and were analyzed. The significant SDIs were identified and classified by the research team and were ranked and prioritized, using the Relative Importance Index (RII) method. The results demonstrated that the identified SDIs could be classified into the following eight main categories: legal, design and technology, project characteristic, project management, material resource, human resource, location, and finance. The outcomes of this study will help project managers and stakeholders identify the causes of schedule delays early in the project and implement effective strategies for improving project performance in low-cost housing projects.

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