Ordinary Sand Research Articles

Manufacturing and application of artificial lightweight aggregate from water treatment sludge

The purpose of this study is to manufacture lightweight aggregates for the recycling of water treatment sludge (WTS), to identify the physical properties of the aggregates, and to present a means by which to utilize the manufactured lightweight aggregates. The chemical composition and thermal properties were examined via a raw materials analysis. The aggregate examined here was fired by the rapid sintering method and the single-particle density and water absorption rate were measured. WTS has a high LOI and the calcined inorganic material has high refractoriness. When 30 wt% of purified sludge was added, the single-particle density of the aggregates was in the range of 0.8–1.2g/㎤ at temperatures of 1150–1200 °C. At temperatures of 1200 °C or higher, ultra-lightweight aggregates having a single-particle density of 0.8 or less could be produced. When applied to concrete by replacing the general aggregate in the concrete, a specimen with strength values of 20–45 ㎫ at 28 days was obtained, and when applied as a filter material, the performance was equal to or exceeded that of ordinary sand.

Comparison of Compressive Strength Value of Concrete Using Pumice Sand with Ordinary Sand as Fine Aggregate

In this study, the method according to the Indonesian National Standard (SNI) was applied. The objects test in the form of cylindrical concrete in which the fine aggregate was pumice sand and ordinary sand. The test objects made were tested for compressive strength. There were 6 test objects made in this study with a size of 15 cm x 30 cm. In detail, 3 test objects were made of pumice sand, while the other 3 test objects were made of ordinary sand. The coarse aggregate for all test objects was crushed stone. The result shown the use of pumice sand as a substitute for fine aggregate can reduce the compressive strength of concrete by 23.53%. However, it can reduce the weight of concrete by 7.03%. Therefore, for construction that prioritizes weight, concrete with pumice sand as fine aggregate is better compared to concreate with ordinary sand as fine aggregate.

Thermophysical and Mechanical Characterization of Poto-Poto Compressed Blocks for Use as Fill Material

This article is devoted to the thermophysical and mechanical study of an eco-material, poto-poto. The objective is to study the influence of the addition of bamboo fibers on the thermophysical properties of the material, while verifying that it complies with the mechanical standards in Cameroon. A double study is therefore carried out: a mechanical characterization whose objective is to determine the mechanical properties (compressive strength, flexural strength and Young’s modulus) and a thermophysical characterization whose objective is to determine the thermal conductivity. For the thermophysical characterization, the asymmetric hot plane experimental setup based on 1D quadrupole modelling was developed and simulated for the estimation of thermal effusivity E and volume heat capacity ρCp. The obtained experimental results show that the apparent thermal conductivity of the developed materials decreases with increasing fibers. Although the reference material (0% fibers) has a much higher conductivity than the ordinary sand block (1.15 Wm-1 K-1), the addition of fibers, already at 2%, contributes to decrease this conductivity (0.95 Wm-1 K-1). From the point of view of thermal insulation and energy savings, the thermal conductivity results obtained show that the use of these materials with a maximum fibercontent of 6% would be a better thermal insulator than sand block or compressed earth brick. The compressive strength obtained is such that Rc > 0.6 MPa. All the materials developed meet the design standards when used as infill.

Research and Analysis on Present Situation of Desert Sand Concrete

Due to the rapid development of civil engineering industry, natural medium and coarse sand resources are increasingly scarce. If desert sand is studied and applied in the field of civil engineering, the shortage of sand resources and high unit price can be greatly solved.Therefore, it is very important to study desert sand instead of ordinary sand. Although the application of desert sand in engineering has made rapid development, many engineers and researchers have done a lot of experiments and in-depth research on the physical and chemical properties, mechanical properties and compaction characteristics of desert sand, and also made a lot of experimental research results. However, at present, because of the different engineering properties, different deserts are used and the test methods are different. Generally speaking, the understanding of this special material with engineering properties is not mature at home and abroad, and it is not widely used in civil engineering.

Reconfigurable Particle Swarm Robotics Powered by Acoustic Vibration Tweezer.

Inspired by natural swarms such as bees and ants, various types of swarm robotic systems have been developed to work together to complete tasks that transcend individual capabilities. Autonomous robots controlled by collective algorithm and colloidal swarms energized by external field have been designed in an attempt to emulate collective behaviors in nature. However, either sophisticated hardware designs or active agents with special electromagnetic properties and microstructural designs are needed. Here, for the first time, we create a swarm robotic system that can make any granular materials an active swarm robot by acoustic vibration tweezer. It should be noted that the particles energized by only one vibration generator are ordinary sand without any microstructural design. Therefore, it is the simplest and lowest cost swarm robot. Particles can display a solid-like aggregate, which is capable of robustly carrying and transporting an object that is about 1 million times heavier than a single particle. Moreover, through the cooperation of two swarm robots, we can achieve cooperative transport of a stick with a length of 1000 times the diameter of a single particle. The particle robot can move in a fluid-like amorphous group, which can change its own shape to adapt to the surrounding environment, thus having a strong environmental adaptability. Besides, it can move quickly (about 600 times the particle diameter per second) in a discrete state. Within one certain particle system, the particle swarm robot can emulate diverse biomimetic collective behaviors through navigated locomotion, multimode transformation, and cooperative transport.

Improvement of traction capacity of industrial railway transport in the Arctic and on the continental shelf

The Russian Arctic is extremely rich in minerals (hydrocarbons, various minerals, precious metals, etc.). In modern conditions, it is of particular importance to develop vast territories located beyond the Arctic Circle, due to their special socio-economic, geopolitical and defense significance. The rapid development of the Yamal field needs a reliable and modern trunk railway. The project called the Northern Latitudinal Railway has been included in the Strategy for the Development of Railway Transport until 2030. At the temperatures below minus 20 °C, the use of ordinary sand to improve adhesion usually has low effect due to a significant increase in the hardness of ice and ice crust. It should be noted that given sand is present at the contact of ice-glazed rails and wheels, their metal–metal interaction is interrupted by of this sandwiched sand interlayer, which leads to a decrease in the traction characteristics of locomotives. To increase the adhesion coefficient in winter, the author has proposed an engineering solution protected by patent No. 2504492, which consists in the feed of pre-heated, for example, using an induction heater, dry quartz sand to the rail–wheel contact zone. This invention allows increasing the coefficient of adhesion and, consequently, the traction force of locomotives on average up to 10%. Currently, we are carrying out studies to solve the problem of removing ice deposits from the working surface of rails using innovative “sandless” methods that eliminate the need of using ordinary sand. The solution to the problem of removing ice from rails will contribute to the creation of a terrestrial year-round communication between Chukotka and the Barents Sea, which duplicates the Northern Sea Route.

Effect of Particle Size of Quartz Sand Filler on Microstructure and Strength of Alkali-Activated Slag-Based Materials

Interaction between quartz sand and water glass has been investigated and characterized by using the Si/Na molar ratio to determine the role of silica in the polycondensation rate and mechanical properties of the synthesized materials as a function of quartz sand particle size. Results of atomic emission spectroscopy, SEM and compressive strength tests show that interactions between sodium silicate solution and quartz sand depend on the degree of dispersibility that determines the degree of amorphization of quartz sand. When using ordinary quartz sand sodium silicate solution acts as a thin layer of glue covering the grains of sand and weakly binds them to each other, while using finely ground quartz sand in the mixture there is a dissolution–precipitation reaction that modifies the surface layers of the particles and more strongly consolidating the granular system. The increase in the molar ratio of Si/Na in sodium silicate solution containing finely ground quartz sand occurs due to the increase in the proportion of amorphous quartz (according to XRD) and corresponds to the described mechanism. Then, samples of alkali-activated slag-based materials with a coarse ordinary quartz sand and finely ground quartz sand were synthesized, compared in terms of strength and the latter characterized by SEM, porosimetry, XRD. The increase of dispersibility and amorphization of quartz sand is established to favors to form consolidated of low-temperature curing materials based on alkali-activated slag and quartz sand with the significantly increased compressive strength from 30–44 MPa for mixtures based on ordinary coarse quartz sand to 95–140 MPa for finely ground slag/sand blended mixture.

The Study of the Characteristics of Sand Concrete Based on Marble Waste Sand

Abstract The present study aims to valorize the waste and in particular the waste from the Fil-fila quarry. The main reason for choosing the waste from this quarry was the need to reduce the impact on the environment (by reducing stockpiling) and the raw material cost (economic reason). This study therefore consists in recovering this type of waste (discarded powder subject to weather changes) as sand in partial replacement of dune sand in the formulation of sand concrete with percentages of 5, 10, 15 and 20 %, by studying the behavior of these concretes in the fresh state (workability, density and occluded air) and the properties in the hardened state (compressive and tensile strength by bending, absorption by immersion, shrinkage and weight loss, chemical effect of HCl and H2SO4 solutions), and subsequently comparing the results obtained with reference samples (0%) based on ordinary sand. Based on the obtained results, it can be concluded that the substitution of ordinary (dune) sand with marble waste sand provides acceptable results from the point of view of workability, strength and durability. These observations are likely to widen the field of applications of these sand concretes based on marble waste.

Experimental Study on Performance Influencing Factors and Reasonable Mixture Ratio of Desert Sand Ceramsite Lightweight Aggregate Concrete

The utilization of desert sand for making ceramsite lightweight aggregate concrete is proposed to make full use of local natural resources in the development of a new type of lightweight and load‐bearing wall material with good energy conservation, waste utilization, and thermal insulation performances. An orthogonal test was conducted to analyze the effects of the water‐binder ratio, sand ratio, desert sand substitution rate, and fly ash content on the slump, apparent density, and tube crushing strength of desert sand ceramsite lightweight aggregate concrete. Thus, the optimal mixture ratio of the desert sand ceramsite concrete was obtained for the LC20 and LC25 strength grades. Based on two reasonable mixture ratios, the physical and mechanical properties of the desert sand ceramsite concrete were investigated. The results revealed that the water‐binder ratio, sand ratio, and desert sand substitution rate were the main influencing factors, and the influence law is essentially consistent with that of ordinary desert sand concrete. Based on the reasonable substitution rate of desert sand, the main physical and mechanical properties of the desert sand ceramsite lightweight aggregate concrete, such as the tube crushing strength, tensile strength, and thermal conductivity, satisfied the requirements of the Chinese code’s specifications. In summary, desert sand can replace ordinary sand in ceramsite lightweight aggregate concrete for the production of new lightweight and load‐bearing wall materials.

Hadîs Musannefâtında Niyet-Amel İlişkisi

İbâdetlerin îfâsı için niyetin ne kadar önemli ve lüzumlu olduğu konusu her Müslüman tarafından bilinen bir gerçektir. Özellikle fıkıh kitaplarına göz atıldığında hemen hemen her ibâdet için delillerden hareketle niyetin hükmünün belirlenmeye çalışıldığı görülmektedir. Hâc ibâdetinde ise neredeyse her nüsük için niyetin hükmü üzerinde durulmaktadır. Bununla beraber hadîs okumalarımız sırasında bu konunun hadîs kitaplarında ve özellikle de musannef türü eserlerde fıkıh kitaplarıyla pek de örtüşmeyen bir şekilde ele alındığını fark ettik. Gerek rivâyetlerde gerekse musanneflerin bâb başlıklarında, bazı ibâdetler hariç niyet kelimesi fıkıh kitaplarında görüldüğü üzere ayrıntılı ve vurgulu olarak yer almamıştır. Bunun en bariz örnekleri olarak abdest ve namaz konusu karşımıza çıkmaktadır. Hz. Peygamber’in gerek abdest gerekse de namaz için niyet ettiği veya sahabeye niyet edin şeklinde bir emrinin vukûu söz konusu değildir. Dolayısıyla bu makalemizde abdest, namaz, oruç, hac ve zekât ibâdetleri özelinde hem hadîsler hem de musanneflerin bâb başlıklarından yola çıkılarak konuyla ilgili mevcut durum tespit edilmeye çalışılacaktır.

Study on Preparation Technology and Antifreeze Performance of Slag Micropowder Pumice Lightweight Aggregate Concrete

To study the influence of the amount of slag micropowder and the mixing ratio on the frost resistance of slag micropowder pumice lightweight aggregate concrete, the LC35 concrete was prepared with S95 grade slag powder, cement, ordinary sand and pumice as raw materials.The slow-freezing method was used to study the failure mode of the sample and the change of mass and compressive strength loss rate.The results show that the mass loss rate of slag micropowder pumice lightweight aggregate concrete after freezing and thawing cycles is small, and the loss of freeze-thaw strength is high. This mainly due to the destruction of aggregate pumice. Meanwhile, because of the Micro-filling effect of slag powder, the tensile strength has an effect of increasing the compactness of the concrete, and can effectively reduce the damage caused by the freeze-thaw cycle to the concrete.

Experimental Study on Volume Deformation of Iron Tailing-steel Slag Aggregate Concrete

Utilization in building materials is one of the main technical ideas for realizing large-scale, high added value recycling of industrial solid wastes such as iron tailings and steel slags. It is common to use only iron tailings or steel slags instead of ordinary sands or stones as concrete aggregates, but using them at the same time and combining their performance advantages to improve the mechanical properties and durability of concrete has not yet appeared. Therefore, sands were replaced by iron tailings as fine aggregates and stones were replaced by steel slags as coarse aggregates to prepare iron tailing-steel slag concrete in this research. And the strength, early crack resistance and long-term volume deformation of iron tailing-steel slag concrete were tested. The results show that iron tailings have negative effect on concrete strength when used as fine aggregates and steel slags are beneficial to concrete strength with a small adding amount. In addition, iron tailings with proper adding amount can inhibit the deformation of concrete caused by steel slags, in consequence of which early crack resistance and volume stability of concrete are improved.

Behavior of sand columns reinforced by vertical geotextile encasement and horizontal geotextile layers

In this paper, the effect of a group of sand columns in the loose soil bed using triaxial tests was studied. To investigate the effect of geotextile reinforcement type on the bearing capacity of these sand columns, Vertical encased sand columns (VESCs) and horizontally reinforced sand columns (HRSCs) were used. Number of sixteen independent triaxial tests and finite element simulation were performed on specimens with a diameter of 100 mm and a height of 200 mm. Specimens were reinforced by either a single sand column or three sand columns with the same area replacement ratio (16%) to evaluate the Influence of the column arrangement. Effect the number of sand columns, the length of vertical encasement and the number of horizontal reinforcing layers were investigated, in terms of bearing capacity improvement and economy. The results indicated that the ultimate bearing capacity of the samples with three ordinary sand columns (OSCs) is eventually about 11% more than samples with an OSC. Also, comparison of the column reinforcing modes showed that four horizontal layers of geotextile achieved similar performance to a vertical encasement geotextile at the 50% of the column height, from the viewpoint of strength improvement, while from the viewpoint of economy, the geotextile needed for encasing the single column is around 2.5 times of the geotextile required for four layers.

Analysis of Filtration Efficiency of Activated Carbon Coated Sand Beds

Sourcing the clean water has remained of the great importance ever since the civilisation has come into the existence. Continuous efforts are being made to find out the innovative methods and techniques to treat water efficiently and economically. In this study, an attempt is made to make efficient water filter, to be used at large scale in water treatment plants, economically and commercially viable. It is made from activated carbon coated sand acquired from thermal degradation of sugar on river sand particles. The carbon coated sand is activated by chemical treatment. It is found that filter function satisfactorily in removing the TDS and dissolved organics from polluted water. The high concentration of carbon on sand have better adsorption power (15% sugar on sand is better than 5% sugar in sand) and higher the number of passes through filter facilitate the better results. Though “ordinary sand” used in conventional systems is good in removing organics but do not removes inorganic dissolved particles. It also could be done by this type of filters. Higher amount of chemicals used in every sector reach back to the prime sources of water. Which requires to be “re-treated” by water treatment plants. Thus, it becomes a necessity to find out innovative techniques to treat water.

Engineering Characteristics and Reinforcement Approaches of Organic Sandy Soil

Organic sandy soil is widely distributed throughout Hainan Island. This study aimed at addressing the distribution, composition, and formation of organic sandy soil. The engineering properties of organic sandy soil were examined. The experimental results showed that the coefficient of uniformity and coefficient of curvature were 2.07 and 1.25, respectively. The maximum dry density and optimum water content were 1.723 g/cm3 and 12.23%, respectively. The undrained shear strength of organic sandy soil was around 37.5 kPa. The effective stress parameters c and φ were around 4 kPa and 23°, respectively. The compound tangent-exponential model was adopted for capturing the stress-strain behavior of organic sandy soil. As the unconfined compressive strength of the cement-admixed organic sandy soil was much lower than that of ordinary sand, some innovative ground improvement technologies were proposed for stabilizing organic sandy soil, such as thermal pile, fiber, and steel-, bamboo-, and freezing-cemented soil columns. The main purpose of these technologies is to enhance the bearing capacity of organic sandy soil but reduce the usage of cement, as the latter is not an eco-friendly material.

Using Waste Vermiculite and Dolomite as Eco-Friendly Additives for Improving the Performance of Porous Concrete

The present study investigated the applicability of waste vermiculite and dolomite as fine aggregate, known as appropriate mineral adsorbents to enhance the quality of urban runoff, for improving the mechanical properties of porous concrete. 180 samples were mixed by adding 5-30% vermiculite and dolomite, as fine aggregate, and combining them with ordinary sand; lime sand (combining of 5-15% of each). Results showed that although adding dolomite culminated in a minor reduction of permeability– average of about 30%-, the average of compressive strength was augmented by 120%. Results of compressive strength of dolomite samples were repeated in mixtures containing vermiculite (an increase of 57%). While exploiting vermiculite in high percentages (20, 25, and 30) resulted in an extensive decrease in the permeability (94%), it was improved to an acceptable level (about 40%) after using vermiculite in combination with ordinary sand (lime sand). All dolomite and improved vermiculite mixtures, after combining vermiculite with ordinary sand, had appropriate performance in draining storm-urban runoff; such that in the weakest case, stimulated storm runoffs with heights of 10, 20, 30 and 40 cm were completely drained only after 17, 36, 59 and 87 seconds, respectively. Also, using vermiculite resulted in reducing the concrete weight (about 100 kg). Generally, although a little reduction in the permeability was seen, but using waste vermiculite and dolomite improved the mechanical properties of porous concrete significantly.

Inline quantification of extrudability of cementitious materials for digital construction

Digital construction (DC) is a new process, and hence, no standard experimental methods for process-specific material characterization are as yet available. This article proposes a methodology for characterizing the extrudability of cement-based materials for DC, both quantitatively and inline. A 3D-printing test device was used for this purpose, which enabled the elimination of most artefacts in the characterization of materials. Unit extrusion energy UEE, defined as the energy consumed per extruded unit volume, was used as the measure of extrudability, lower UEE implying higher extrudability. The results obtained using the proposed approach were compared with results of a simple ram-extruder, slump-flow and viscometer tests. Two fine-grained concrete mixtures under investigation, one with ordinary sand and one with very fine sand, having respective yield stresses of 306.2 Pa and 642.7 Pa, were characterized. They showed a significant difference in their extrudability: the UEE needed in the case of material with finer sand was 1.62 times higher than that of the mixture with coarser sand. Interestingly, average ram extrusion force for the finer mixture was much lower than that of the coarser mix, underlining the challenges in material characterization and the need to consider the possible artefacts of various testing methods. Comparative analyses substantiated the significance of the proposed inline extrudability quantification method for DC.

Investigation on Potential of Recycle Plastic Bottles as a Crash Cushion for Road Barrier

Road accident is a major problem in the country and should be dealt with an effective ways. Road furniture is one of the factors that contributing an accidents than other factors. Therefore, this study focuses on waste material such as recycle plastic bottle that potential to be used as a road barrier and crash cushion. The objective of this study are to investigate the potential of plastic bottles filled with sand as crash cushion, examine the impact strength of plastic bottles and designing crash cushion by using recycled materials. Some plastic bottles of soft drinks containing ordinary sand was prepared and undergone experimental and simulation works. Free fall Impact test that imposed on the plastic bottles has been carried out to identify the strength and its energy absorption. The numerical simulation of impact test was conducted using Finite Element Method to obtain impact failure and to observe its details response under low velocity impact loads. The numerical results by employing FEM well agreed with practical works. Where, the absorption of energy from the impact test shows that the difference does not exceed 50%. In addition, the deformation of both test are almost similar. Therefore, the use of recycled materials such as plastic bottles filled with sand as crash cushions that can be considered as alternative and environmentally friendly materials.

Strength and consolidation characteristics of clay with geotextile-encased sand column

Installing sand columns in clays is a common ground improvement technique used to treat soft soils, and the inclusion of geotextile to encase the sand column can further improve the performance of the reinforced clay composite. In this work, the shear strength and consolidation characteristics of clay, clay with an ordinary sand column (OSC) and clay with a geotextile encased sand column (GESC) were investigated by carrying out laboratory direct shear and oedometer tests to study the response of the reinforced clay composite under both lateral and vertical loading conditions. It was found that the OSC and GESC significantly increased the shear strength of the clay, mainly by improving the friction angle, with little impact on the apparent cohesion. Furthermore, the OSC and GESC reduced the compression index, swell index, and recompression index of the clay to some extent. The secondary compression indexes obtained from the reloading stage were lower than those from the initial loading stage, indicating that over-consolidated clay has a lower secondary compression index than normally consolidated clay. The coefficients of consolidation showed an upward trend as the effective consolidation stress increased. In addition, the compressibility and hydraulic conductivity tended to decrease with increasing effective consolidation stress.

Generation of Electricity Using Sand

Conserving energy has become the biggest issue in the present scenario. This paper proposes an economical and affordable method for the design and manufacturing of sand power generation. Due to the development and modernization, the electricity demand is increasing to the high extent. To overcome this demand globally effectively without any destructive effect on the environment is possible by using sand power generation. The sand is available abundantly on the surface of the earth. The basic concept of Sand power generation is, the sand Power generator is a simple technology, more economical, more effortless can meet from domestic (household) to average power requirements. In this process, ordinary sand placed in the main funnel is allowed to fall on the blades of a sand wheel through conveyor belts which leads to rotate the turbine, which is used to generate power and stored in a DC battery. The concept of sand power generation is simple. When sand moves down from the higher altitude to lower one its potential energy is converted into kinetic energy. This motion is converted into rotational motion and that rotational motion is converted into electricity by using a Mini DC generator.