Iterative methodology on locating a cement plant

In this study, a cement plant location was determined by considering essential parameters such as the locations of resources and their importance in the manufacturing process. A crucial mathematical problem, named Weber problem, reinforced the decision of the method of allocating the factory. Additionally, not only the limitations of the cement production but also the importance weights of goods used in the manufacturing were taken into account in the iterative methodology in order to answer the engineering question via the mathematical problem. As a result, by optimizing the case through the iterations introduced in the paper, the location of the cement plant was set. Hence several losses such as extra travel distances and time wasting in transportation were minimized.No sponso

Effects of iron powder on properties of geopolymers subjected to different curing regimes

393-408Silica fume, slag and iron powder are by-products from various industries. In parallel with development of industrial technology, it is also known that these by-products which cause rapid pollution of the environment are also harmful to human health because they are easily respirable. For this reason, a series of experiments were carried out to determine physical and mechanical properties on samples prepared using different blend designs to examine the effect of factors such as curing conditions, binder type and waste iron powder content. Percentages of iron powder added to replace the aggregate are 10%, 20%, 30% and 40% by volume of slag aggregate. It was observed that the substitution of 30% by volume iron powder instead of slag in geopolymer mortars is the most effective in increasing splitting tensile strength. For 40% partial replacement of fine aggregates with iron powder, increases in compressive strength and flexural strength of slag-based mortars were 7.2% and 43.4%, respectively, compared to mortar without iron powder at 60°C curing conditions

Effects of iron powder on properties of geopolymers subjected to different curing regimes

Silica fume, slag and iron powder are by-products from various industries. In parallel with development of industrial technology, it is also known that these by-products which cause rapid pollution of the environment are also harmful to human health because they are easily respirable. For this reason, a series of experiments were carried out to determine physical and mechanical properties on samples prepared using different blend designs to examine the effect of factors such as curing conditions, binder type and waste iron powder content. The percentages of iron powder added to replace the aggregate are 10%, 20%, 30% and 40% by volume of the slag aggregate. It was observed that the substitution of 30% by volume iron powder instead of slag in geopolymer mortars is the most effective in increasing splitting tensile strength. For 40% partial replacement of fine aggregates with iron powder, the increases in the compressive strength and flexural strength of slag-based mortars were 7.2% and 43.4%, respectively, compared to mortar without iron powder at 60°C curing conditions

Utilisation of different types of coal fly ash in the production of ceramic tiles

The influence of varying proportions of different types of fly ash (used in place of feldspar) and different sintering temperatures on the sintered properties of ceramic tile bodies was evaluated. The results indicated that sintering ceramic tiles with a high fly ash content at a high temperature caused a decrease in the properties because of bloating. The ceramic samples containing a higher amount of fly ash that were sintered at low temperature exhibited lower water absorption, larger shrinkage and strength because of the densification observed also in microstructural investigation.<br><br>Se ha evaluado la influencia de la proporción de diferentes tipos de cenizas volantes (en lugar de feldespato) y diferentes temperaturas de sinterización en las propiedades de soportes cerámicos. Los resultados indicaron que las composiciones con un alto contenido de cenizas volantes provocaron una disminución en las propiedades de las piczas cocidas a alta temperatura como consecuencia del hinchamiento. Las composiciones con una mayor cantidad de cenizas sinterizadas a baja temperatura mostraron una menor absorción de agua, mayor contracción y resistencia mecánica debido a la densificación como también se observó en la investigación microestructural

Behavior of mortars produced with construction wastes exposed to different treatments

203-214Performance of cement mortars prepared by replacing 30% and 60% of crushed calcareous fine aggregate (CNA) with waste fine aggregates namely, crushed brick aggregate (CBA), crushed marble aggregate (CMA) and crushed ceramic aggregate (CCA) is investigated. For this purpose, absorption, unit weight, compressive strength, flexural strength, modulus of elasticity, capillarity, drying shrinkage, resistance to high temperature up to 400°C and resistance to freeze-thaw cycles are determined. In addition, X-ray flourescence (XRF) and X-ray diffraction (XRD) are performed on cement and aggregates and scanning electron microscopy (SEM) analysis is conducted on mortars in order to examine their mineralogy and morphology. It is found from the experimental results that CBA mortars exhibited the lowest strength values and the worst durability properties. However, CBA and CCA mortars are more effective in relative strength gain at 56 days. Residual strength values of CCA and CMA mortars after freze-thaw and high temperature resistance tests are higher than those of other mortars

Effects of Silica Fume and Micro Silica on the Properties of Mortars Containing Waste PVC Plastic Fibers

Investigations on the usability of waste plastics as a new generation of construction materials have become one of the main concerns of researchers and engineers in recent decades. Waste plastics can be used either as aggregate replacement or as fiber reinforcement to enhance the properties of cementitious mixtures. This study focuses on the properties of waste PVC fiber-reinforced mortars containing silica fume and micro silica. Plastic fibers were added to the mortar mixes by volume fractions of 0%, 1%, 2%, and 3%. Cement was replaced by micro silica and silica fume by 5%, 10%, and 15% by weight of cement, respectively. In total, 28 different groups of mortars were produced. The results showed an enhanced ductility and deformation behavior of mortars upon the addition of waste PVC plastic fibers. It can be seen that fibers restricted crack propagation and maintained integrity, hence improving the ductility of the mortars. On the other hand, the addition of fibers led to a reduction in the physical and mechanical properties of the mortar samples. The compressive strength of the mortar samples decreased gradually by increasing the fiber content. Cement replacement by silica fume improved mechanical and microstructural properties of the mortars. The results also demonstrated that silica fume significantly decreased the porosity and water absorption capacity of mortar samples

Physical and Mechanical Properties of Silica Fume and Calcium Hydroxide Based Geopolymers

Conventional portland cement has found worldwide usage in the production of cementitious materials in recent years. Nevertheless, environmental problems such as high demand of raw materials, energy consumption and high amount of carbon dioxide emission take place before and during manufacturing process. The attempts have been made to seek alternative binders and develop supplementary materials for construction sector. Therefore, this study reports the results of an experimental program on the comparison of geopolymers with different compositions in terms of evaluating their physical and mechanical behavior. For that purpose, the effect of binder types and amount of binders and alkali activator (sodium hydroxide) was investigated. In addition, acidic pumice and waste aluminium particles were also used as fine aggregate and air entraining agent, respectively, in geopolymer production. The test results revealed that as the content of alkali activator increased, compressive and flexural strength decreased. Addition of waste aluminium particles decreased bulk density and strength owing to the some extent of entrained air