scholarly journals EFFECT OF ORGANIC SOIL ON STRENGTH PROPERTIES OF COMPRESSED CEMENT-SOIL BLOCK

2017 ◽  
Vol 8 (1) ◽  
pp. 41-48
Author(s):  
M. S. Shirin ◽  
M. M. Ali ◽  
M. R. Hasan ◽  
Md. Saiful Islam

Compressed cement-soil block is used as low cost building material. In the south-western region of Bangladesh, there is availability of organic soil which is in the formation of overlying layer. Moreover, sandy materials do not occur and are not found easily in Bangladesh. The scarcity of sandy materials has led to the increase of the retail price and subsequently to higher production cost. So organic soil materials have been used as filler directly to produce cement-soil block. In this study, the compressive and flexural strengths of cement-soil block of density 1448kg/m³ to 1611kg/m³ with specified ratio of cement content were investigated using prism specimens. The observed elapsed periods were 1, 3, 7, 14, 28, 56 and 112 days with the variation of organic contents of 2%, 5%, 10%, 20% and 40%. Preferable results on the 28th day indicated that the compressive strength and the flexural strength of cement-soil block with 20% organic content increased by 125% and 102% respectively. Moreover, the influence of density on the strength properties of cement-soil block was found to be higher than the age of the specimen.

Author(s):  
Vitaliy A. Zuyevskiy ◽  
Daniil O. Klimyuk ◽  
Ivan A. Shemberev

Gear pumps are an important element of many production systems and their replacement in case of failure can be quite expensive, so it is important to have a modern and well-tuned technology for their recovery. There are many methods for restoring the pump's performance, depending on the reason that led to its failure. (Research purpose) The research purpose is in determining what causes most often lead to loss of pump performance, and developing a recovery method that provides the greatest post-repair service life of the pump and low cost of repair. (Materials and methods) Authors took into account that the applied coatings must have sufficient adhesion strength and resistance to mechanical, thermal and corrosion loads during operation. It was found that most often significant leaks of the working fluid, leading to failure, occur due to an increase in the gap between the inner surface of the housing and the gears due to active wear of the housing wells. Authors determined that the method of electric spark treatment of worn-out housing wells is best suited to perform the task (a large post-repair resource and low costs). (Results and discussion) It was found by laboratory studies of the adhesion strength of electric spark coatings with various electrodes that the best transfer of the material to the substrate is provided by bronze electrodes BrMKts3-1. It was noted that the coatings applied using the BrMKts3-1 electrode have high strength properties. (Conclusions) Research conducted in the center for collective use "Nano-Center" VIM confirmed the possibility of effective recovery of the gear pump by electric spark treatment.


Author(s):  
Andres Winston C. Oreta ◽  
Maejann E. Cuartero ◽  
Nikko Paolo P. Villanueva

<p>Sustainable construction can be promoted by producing construction materials with recycled waste. This study aims to address the issue of recycling plastic wastes and providing a means of livelihood in a relocation site of typhoon victims and urban settlers in Metro Manila by exploring the production of quality concrete hollow blocks (CHB) mixed with waste plastic wastes. In the study, the strength properties of concrete with various types of plastic wastes (PW) such as plastic bags (PB) and noodle wrappers (NW) as substitute to fine aggregates were investigated. Different percent substitutions, specifically 2.5%, 5%, 7.5% and 10%, were considered for each mix. The behaviour and strength properties of the concrete with and without PW were analysed and compared Moreover, the microscopic structures of the various types of mixes were observed using a Scanning Electron Microscopy (SEM) and related to the failure mode and strength performance. Results show that concrete with PB outperformed the other concrete mixes with plastics due to the plastic bag’s high stretchable property, compared to the noodle wrappers. In addition, plastics, in general, provide additional ductility to the concrete enabling them to tolerate more deformation at lower loads. The final product of the study is a mix design for producing non-load bearing concrete hollow blocks (CHB) that can be used for low-cost housing in the Philippines.</p>


2019 ◽  
Vol 18 (5) ◽  
pp. 2359-2393 ◽  
Author(s):  
Maarten Janssen ◽  
Sandro Shelegia

Abstract This paper studies vertical relations in a search market. As the wholesale arrangement between a manufacturer and its retailers is typically unobserved by consumers, their beliefs about who is to be blamed for a price deviation play a crucial role in determining wholesale and retail prices. The common assumption in the consumer search literature is that consumers exclusively blame an individual retailer for a price deviation. We show that in the vertical relations context, predictions based on this assumption are not robust in the sense that if consumers hold the upstream manufacturer at least partially responsible for the deviation, equilibrium predictions are qualitatively different. For robust beliefs, the vertical model can explain a variety of observations, such as retail price rigidity (or, alternatively, low cost pass-through), nonmonotonicity of retail prices in search costs, and (seemingly) collusive retail behavior. The model can be used to study a monopoly online platform that sells access to final consumers.


2010 ◽  
Vol 19 (7) ◽  
pp. 961 ◽  
Author(s):  
Laura L. Bourgeau-Chavez ◽  
Gordon C. Garwood ◽  
Kevin Riordan ◽  
Benjamin W. Koziol ◽  
James Slawski

Water content reflectometry is a method used by many commercial manufacturers of affordable sensors to electronically estimate soil moisture content. Field‐deployable and handheld water content reflectometry probes were used in a variety of organic soil‐profile types in Alaska. These probes were calibrated using 65 organic soil samples harvested from these burned and unburned, primarily moss‐dominated sites in the boreal forest. Probe output was compared with gravimetrically measured volumetric moisture content, to produce calibration algorithms for surface‐down‐inserted handheld probes in specific soil‐profile types, as well as field‐deployable horizontally inserted probes in specific organic soil horizons. General organic algorithms for each probe type were also developed. Calibrations are statistically compared to determine their suitability. The resulting calibrations showed good agreement with in situ validation and varied from the default mineral‐soil‐based calibrations by 20% or more. These results are of particular interest to researchers measuring soil moisture content with water content reflectometry probes in soils with high organic content.


2019 ◽  
Vol 9 (14) ◽  
pp. 2800 ◽  
Author(s):  
Maria S. Santos ◽  
Patrícia Fradinho ◽  
Sandro Martins ◽  
Ana G. Lima ◽  
Ricardo M. S. Boavida Ferreira ◽  
...  

Cheese whey has been described as an environmental hazard due to its high organic content. Although it has been suggested that whey can be used as food disinfectant, it continues to pose an environmental problem because it still contains a high organic load. Here, we aimed to develop a low-cost, scalable fermentation protocol to produce a disinfectant from dairy waste that has very little organic content and high levels of lactic acid. Fermentation was achieved with industrial whey from ewe, goat, and cow’s milk, using a specific mesophilic-lactic acid bacteria starter mix over 120 h, which yielded the highest lactic acid production and the lowest lactose content. Antibacterial activity was observed against Listeria monocytogenes, Salmonella enterica, and Escherichia coli O157:H7, plus a total of thirteen other food pathogenic and spoilage strains, and antibacterial activities were determined to be highest after 120 h. We further validated this whey’s application as a disinfectant in shredded lettuce and compared its efficacy to that of chlorine, evaluating microbial quality, texture, color, and sensory perception, pH, and O2 and CO2 determinations. Results showed that not only was microbial quality better when using our whey solution (p < 0.05), but also the quality indicators for whey were statistically similar to those treated with chlorine. Hence, our work validates the use of an industrial waste whey as a low-cost, efficient, and environmentally safe disinfectant, with potential applications for minimally processed foodstuffs as an alternative to chlorine.


2011 ◽  
Vol 250-253 ◽  
pp. 421-424
Author(s):  
Ying Xia Yu ◽  
Yu Feng Jiao ◽  
Bin Liang ◽  
Wei Zhang

Based on the compaction test and unconfined compression test of cement soil, the optimum water content is ascertained. The relationship is studied about cement content, curing time and unconfined compression strengths, ultimate strain of compacted cement soil in this paper. The results indicate that the unconfined compression strengths increase in linear with the increase of curing time and cement content on the whole, and the ultimate strains decrease with the increase of cement content and curing time. The results provide theoretical basis for rational construction mixture ratio and parameter which have been successfully used to a project and achieved good economic benefit.


2020 ◽  
Vol 17 (2) ◽  
pp. 1306-1310
Author(s):  
Nor Hasanah Abdul Shukor Lim ◽  
Farah Hanum Shaari ◽  
Eliza Hanum Shaari ◽  
Abdul Rahman Mohd Sam ◽  
Nur Hafizah Abd Khalid ◽  
...  

The application of copious and low-cost waste items, mainly from neat resources, has developed extra demanding than always. This paper debates the utilization of bamboo waste as original and new things in the building industry. The study comprises rudimentary characteristics, containing the morphology of the ingredients in terms of variations in the composition procedure. The bamboo ash was recycled as cement respect to with 10%, 20% and 30% replacement. The materials characteristic of bamboo ash, strength activity index, fresh state properties and strength properties of concrete were examined too. The concrete was cast in 100×100×100 mm cube size and compared with conventional concrete. The result how that bamboo ash show pozzolanic properties and 20% cement replacement by bamboo ash give comparable strength with control specimens at 28 days, which achieved the target design strength. The total outcomes have exposed that the addition of bamboo ash can produce concrete with more power, higher class and sustainability.


2013 ◽  
Vol 438-439 ◽  
pp. 197-201
Author(s):  
Xian Hua Yao ◽  
Peng Li ◽  
Jun Feng Guan

Based on the generalization and analysis of laboratory experimental results on mix ratio, the effects of various factors such as cement content, water-cement ratio, curing time, curing conditions and types of cement on the mechanical properties of unconfined compressive strength of cement soil are presented. Results show that the unconfined compressive strength of cement soil increases with the growing curing time, and it is greatly affected by the cement content, water-cement ratio, cement types and curing time, while the effect of curing conditions is weak with a cement content of more than 10%. Moreover, the stress-strain of the cement soil responds with the cement content and curing time, increasing curing time and cement content makes the cement soil to be harder and brittle, and leads to a larger Young's modulus.


2015 ◽  
Vol 61 (4) ◽  
pp. 59-78 ◽  
Author(s):  
F. C. Wang ◽  
W. Song

A study was undertaken to investigate the effects of crumb rubber on the strength and mechanical behaviour of Rubberized cement soil (RCS). In the present investigation, 26 groups of soil samples were prepared at five different percentages of crumb rubber content, four different percentages of cement content and two different finenesses of crumb rubber particle. Compressive strength tests were carried out at the curing age of 7 days, 14 days, 28 days and 90 days. The test results indicated that the inclusion of crumb rubber within cement soil leads to a decrease in the compressive strength and stiffness and improves the cement soil’s brittle behaviour to a more ductile one. A reduction of up to 31% in the compressive strength happened in the 20% crumb content group. The compressive strength increases with the increase in the cement content. And the enlargement of cement content is more efficient at low cement content.


2019 ◽  
Vol 5 (12) ◽  
pp. 2587-2597
Author(s):  
Sajid Kamil Zemam ◽  
Sa'ad Fahad Resan ◽  
Musab Sabah Abed

Construction materials made of renewable resources have promising potential given their low cost, availability, and environmental friendliness. Although hemp fibers are the most extensively used fiber in the eco-friendly building sector, their unavailability hinders their application in Iraq. This study aimed to overcome the absence of hemp fiber in Iraq and develop a new sustainable construction material, strawcrete, by using wheat straw and traditional lime as the base binder. A comparable method of developing hempcrete was established. The experimental program adopted novel Mixing Sequence Techniques (MSTs), which depended on changing the sequence of mixed material with fixed proportions. The orientation of the applied load and the specimen’s aspect ratio were also studied. The mixing proportion was 4:1:1 (fiber/binder/water) by volume. Results showed that the developed strawcrete had a dry unit weight ranging from 645 kg/m3 to 734 kg/m3 and a compressive strength ranging from 1.8 MPa to 3.8 MPa. The enhanced physical and strength properties varied with the MST and loading orientation. The properties of the developed hempcrete were compared with those of strawcrete.


Sign in / Sign up

Export Citation Format

Share Document