Papers by Keyword: Bulk Density

Abstract: A study was conducted to evaluate the soil strength, physicochemical characteristics and yield of fluted pumpkin (Telfaira occidentalis) under different fertilizer sources in an Afisoil of Akure, Ondo State, Southwestern Nigeria. Four treatment, which include: Poultry manure (10 tom/ha), organomineral fertilizer (5 tom/ha), mineral fertilizer (5 tom/ha) and the control (0 fertilizer), replicated four times in a randomized complete block design (RCBD) were experimented in two blocks to make a total of 32 plots. Soil samples were collected randomly at 100, 200, 300, 400 and 500 mm depths and analyzed to determine bulk density (BD), total porosity (PT), micro porosity (MIP) and macro porosity (MAP) following standard procedures. Plant parameters (plant height, number of leaves, stem girth and leave yield were measured weekly to determine response of fluted pumpkin to the different fertilizer sources. Results showed that the soil of the site is predominantly sandy clay loam. The pH of the soil under the different fertility treatment showed an increasing order of the form: mineral fertilizer (MF) < control (C) < Organic manure (OM) < organomineral fertilizer (OML) with values 4.26 < 4.96 < 5.46 < 5.5. Leaf yield of fluted pumpkin was highest in treatment plot that received mineral fertilizer when compared with other soil treatments. Fertlizer sources produced no significant difference (P > 0.05) in the height of fluted pumpkin. Result of this research is useful for local farmers and policy makers in the choice of appropriate soil amendment and management system for fluted pumpkin in the study area.

Abstract: This paper explores the production and properties of geopolymer cement mortar using laterite soils. The aim was to evaluate the laterite-based geopolymer mortars for masonry bedding applications. The testing programme encompassed three series of mixes tested to determine setting times, flowability, flexural strength and compressive strength. Two types of sands were used including standard sand and natural sand. The effect of water-to-laterite ratios, activating agent concentration, and cement-to-sand ratio were established. The properties of standard cement paste, and mortar were used as a reference. The study found that geopolymer mortar made from laterite meets the requirements for masonry bedding.

Abstract: The presented work presents the results of the studies carried out to elucidate the possibility of obtaining by the microencapsulation method of powdered polyetheretherketones and spherical copolyetheretherketones recommended for use in 3D-printing. The influence of temperature-time and concentration parameters, the reaction medium on the size of microencapsulated particles of polyetheretherketones and copolyetheretherketones was determined. It was determined that the bulk density of microencapsulated particles of polyetheretherketone and copolyetheretherketones is 8-10 times higher than similar unencapsulated ones.

Abstract: Fine powders of strontium hexaferrite are widely used in powder metallurgy for the production of permanent magnets resistant to atmospheric oxygen and high working temperatures. Obtaining powders with predefined technological characteristics in minimal time and with minimal energy consumption is an actual problem of powder metallurgy. The paper provides the results of experimental studies of technological characteristics of strontium hexaferrite powder (SrFe₁₂O₁₉) during milling in a beater mill. Mechanical milling of coarse strontium hexaferrite was carried out in the mill with the system of rotating beaters for 120 minutes without and with the creation of a pseudo fluidized bed. The fluidization was formed by a perpendicular constant and alternating magnetic field with induction gradients of 150 and 210 mT/m. Average particle size and powder bulk density dependencies from milling time were studied. Experimental data show that milling with the formation of a magneto fluidized bed allows intensifying the process. Beginning from 70 minutes, the dependencies of average particle size and bulk density come to almost asymptotic behavior making further milling rather ineffective. Carried out research allows choosing optimal milling duration for obtaining the required average particle size.

Abstract: The harmful impact of Portland cement manufacture on a global scale has prompted an extensive search for clinker replacement materials and alternative low CO₂ cements. This paper investigated prospects and application of Calcined Clay Pozzolan with Hydraulic Lime in built industry. Limestone and Raw clay from Ewekoro and Owode-Ketu areas in Ogun State were sourced for the production after being calcined in kiln at temperatures of 950°C and 700°C for 2 hours respectively. Binders were produced by blending Calcined lime (L) and Calcined clay (C) together by mass in different variations (20%L:80%C; 40%L:60%C; 60%L:40%C; 80%L:20%C; 100%L:0%C). Consequently, these binders were mixed with fine aggregate to produce mortar cubes at a mix ratio and water cement ratio of 1:3 and 0.5 respectively. An average of 3 cubes were cast per mix to produce a total of 90, 100mm cubes and cured by water sprinkling for 3, 7, 14, 21, 28 and 90 days respectively. These cubes were subjected to bulk density and compressive strength tests in order to ascertain their durability. Owode-Ketu calcined clay was found to be a class N Pozzolana according to ASTM C618-08. The densities and compressive strengths of the various cubes ranged between 1785 – 1870 kg/m³ and 0.15 – 1.09 MPa respectively for all the curing periods. The binder 60%L:40%C was found to be the best of all the binders owing to its compressive strength (0.89 MPa) after 28 days curing period. All binders except 100%L:0%C could be used in any masonry, rendering, plastering and pointing application because they exhibited compressive strengths in the range of 0.4 to 2.5 MPa after 28 days curing period.

Abstract: The use of the periwinkle shell in the production of lightweight concrete has been studied and accepted to be used for concrete works. Hard water containing detergent-like chemicals has been observed to be used in mixing locally produced concrete. This exploratory study is on the effect of water mixed with detergent in a concrete prepared with the periwinkle shell as a coarse aggregate. A total of 27 concrete cubes of size 150mmx150mmx150mm were prepared in the laboratory with a mix ratio of 1:2:4. A water-cement ratio of 0.4 was used with the addition of detergent at varying percentages (0%, 0.3% and 0.6). The cubes were cured in water and tested at 7days, 14days and 28days respectively. Laboratory tests, which includes bulk density, specific gravity, grain size analysis, slump and the compressive strength test was carried out on the aggregates and concrete. The periwinkle shell had a bulk density of 1440kg/m³and a specific gravity of 2.50. The workability tested revealed that the slump values increased with increase in the percentages of detergent. The compressive strength at 28days and at 0.3% and 0.6% were 12.58N/mm² and 14.06N/mm² respectively. It was observed that the compressive strength decreased with the addition of detergent because of the tiny air bubbles introduced into the concrete by the detergent. From the results of the study, it can safely be concluded that the use of detergent contaminated water in concrete production will reduce its compressive strength and increase its workability.

Abstract: Malaysia has been recognized in recent decades as one of the world's leading palm oil producers and exporters. The number of palm oil mills multiplies each year, increasing the capacity of fresh fruit bunch waste or effluent discharged. Countless numbers of research and development, as well as implementation, have been dedicated to advancing the pollution control technologies. Most of the research is to treat and manage liquid and solid waste generated from palm oil mills. The main reason for such tremendous efforts is that the waste coming from palm oil mills has been declared as one of the pollution sources in the world. Thus, the purpose of this study was to utilize treated palm oil mill effluent (POME) sludge from the electrocoagulation process to produce bricks. Here, three different dilution rates, which was 60%, 90% and 100% of POME concentration have been analyzed in the electrocoagulation process, respectively. After the electrocoagulation process, the characteristics of POME effluents were evaluated, and the treated POME sludge was collected. Instead of being discarded after the treatment, the treated waste sludge from the electrocoagulation process was used to make bricks. Three different bricks labelled (A, B and C) from treated POME sludge from the electrocoagulation process (60%, 90% and 100%) were fabricated. These bricks have been analyzed based on the JKR Standard Specifications for Building Works. Data obtained showed that the compressive strength for the bricks (A, B and C) after seven days were 6.076, 8.233, and 6.344 N/mm². Meanwhile, the bulk density of the bricks (A, B and C) were 2247.92, 2233.95, and 2094.33 kg/m³. The results showed that the compressive strength for these brick samples had met the JKR Standard Specification for Building Works of 5.2 N/mm². It can be deduced that the bricks from treated POME can be a greener product compared to the traditional bricks. Moreover, the concept of a circular economy is adapted in this study to eliminate waste for a long-term sustainable environment.

Abstract: Sandcrete block is a vital building material used in the construction of building structures. The sandcrete blocks are produced by different manufacturers using river sand obtained from different locations as aggregate material without recourse to the minimum quality standard for the blocks produced. The study assessed the strength parameters of river sand used as an aggregate material in block production to determine its quality and suitability in relation to the strength of block produced. Three (3) block manufacturing sites in Nigeria were visited and 27 (twenty-seven) blocks of size 450 mm x 225 mm x 225 mm were selected randomly from the sites. The properties of the river sand was analyzed through sieve analyses, bulk density, silt content and water absorption while the compressive strength of the blocks was also tested. The result of sieve analysis of the river sand used in block production for this study all satisfied the particle size requirements of BS EN 933-1:1997 for general construction work including block production. The result of the study also shows that blocks produced with the river sand after 28days have an average compressive strength of 1.23 N/mm2 (SW), 1.54 N/mm2 (SE) and 1.95N/mm2 (NE). The study, therefore, concluded and recommended that regulatory and professional bodies in partnership with relevant associations should organize seminars for producers of sandcrete blocks on the best practices involved in producing quality sandcrete blocks.

Abstract: In the production of steel in a state-of-the art arc furnace, there are two serious issues, resulting from a decrease in bulk density of burden materials, and an increase in non-ferrous metals concentration. The paper presents the analysis results of changes in the chemical composition of iron-containing materials related with an increase in the content of non-ferrous metals: copper, tin, lead, antimony and unspecified metals in a given steel grade and a decrease in the bulk density of burden materials. A method of reducing impurities by means of using pellets produced from natural raw materials, that are pure in terms of impurities, is presented. A method of setting up charging of burden materials with different bulk density, using the filling coefficient of the furnace operating volume, is proposed. Combined burden materials that include various types of scrap and non-ferrous metals of iron-ore pellets, that are pure in terms of impurities, will ensure high-quality steel production.

Abstract: This article presents the results of research on the use of unstable steel slag with a fraction of 0/8 mm as a 100% substitute for natural aggregate in concrete production. Two types of cements were used for the production of concrete: Portland cement CEM I 42.5N and hybrid cement H-CEMENT. Both of these cements were produced by the company Považská cementárna, a.s., Ladce. The main objective of this study was to assess the suitable type of binder to be combined with unstable steel slag in the production of concrete composite. The prepared concrete was used to test the properties of a fresh concrete mix, i.e. its consistency and bulk density. Hardened concrete was used to test the strength and deformation properties, including cube strength after 3, 7, 14, 21, 28 and 90 days, as well as prism strength after 28 days. The static modulus of elasticity was determined using prisms after 28 days of age of the test specimens. Our attention was also focused on determining the class of leachability of the concretes based on steel slag with CEM I 42.5N and H-CEMENT. The durability of concrete prepared on the basis of steel slag was tested in an environment with increased temperature and pressure. The results of the strength characteristics tests show a difference between the 28-day average cube strength of concrete using CEM I 42.5N and H-CEMENT (34.6 MPa and 29.1 MPa), while after 90 days, the average cube strength value stabilized at about 38 MPa. The average values ​​of the static modulus of elasticity when using CEM I 42.5N and H-CEMENT are almost identical, achieving values ​​of 32.5 GPa and 32.8 GPa, respectively. Concrete based on steel slag with CEM I 42.5N and H-CEMENT can be included in leachability class IIb. The results of the durability test of concrete based on steel slag in an environment with increased temperature and pressure confirmed the use of H-CEMENT hybrid cement from the company Považská cementáren, a.s., Ladce, as a suitable binder. .