Papers by Keyword: Aggregate

Abstract: Pavement failure occurs mostly due to poor selection of aggregate, which is highly dependent on aggregate petrography. The limited number of studies has been carried out in the past to relate the minerology of aggregate with the asphalt mix performance. This research aims to link the minerology of aggregate to the rutting of the asphalt pavement. In this study three different quarries of aggregates were collected for study i.e., Pathargarh, Surajgali and Murunj, Pakistan. Physical and mechanical properties of selected aggregate were determined before preparing the mix design. Aggregate properties were well within the limit specified by National Highway Authority (NHA). Then performance tests i.e., Hamburg wheel tracker test were performed on the asphalt mix to determine the rutting. The results showed that Pathargarh and Surajgali aggregate contains 96 and 95 percent carbonate making it basic. In contrast 84 percent quartz were found in Murunj aggregate. Rutting value of Pathargarh is better followed by Surajgali i.e., 3.43 mm and then Murunj 8.63mm. This study concludes that carbonate aggregate has rough texture making it better adhesion with bitumen, while quartz has poor adhesion with bitumen due to its smooth texture making it more susceptible to rutting.

Abstract: Self-compacting concrete (SCC) is a high-performance material that flows freely and consolidates without segregation or bleeding. This study investigated the effectiveness of incorporating coconut fiber into SCC to improve its strength and toughness. Three mixtures with coconut fiber inclusions of 0.2%, 0.4%, and 0.6% by weight of cement were used. The addition of coconut fiber reduced the workability and passing ability of the concrete, but all mixes met the SCC specification. The CFRSCC with 0.2% had the highest compressive and flexural strengths. The study concluded that adding 0.2% coconut fiber to SCC can increase its strength. The use of natural fibers like coconut can enhance the properties of concrete and could be an alternative to synthetic fibers, especially in regions where natural fibers are locally available and cost-effective.

Abstract: Using alternative resources from industrial by-products to produce aggregates while keeping production costs as low as possible would be environmentally beneficial and profitable. This study aims to examine the effect of the pore on mortar properties with eggshell powder (ESP) as its fine aggregate alternative based on two fundamental properties: microstructural and mechanical strength. The study replaced the sands (by volume) with ESP in the usual mortar mix with 10%, 20%, 30%, 40% and 50% chicken eggshell powder. The mortars underwent a wet curing period of 56 days with five observation days. The standard mortar properties, such as pH, carbonation depth, compressive strength, and sorptivity, were investigated. The findings show that the replacement rate significantly impacts the water-cement ratio, carbonation rate, sorptivity and compression strength. The additional calcareous of ESP is believed to have improved the mechanical component of the connection. There are no significant differences in pH for the control (R₀) and modified mortars. The greatest replacement percentage of 20% is advantageous for carbonation rate acceleration, sorptivity and early compressive strength. However, if the specifier focuses on pH and sorptivity improvements, no formulation alteration is required.

Abstract: The improvement of mixture quality has been the priority of the modern-day construction industry while reducing the financial implications of the final product. This investigation concentrated on the application of glass as fine aggregate in the production of concrete. The fine aggregates used were partially substituted with fine glass. The replacement was done at (0, 10, 20, 30, 40, and 50%) by weight of fine aggregates, with other materials constant. A concrete mixture was prepared and the slump flow test and density were examined. The concrete specimens were produced, cured, and compressive, flexural, and splitting tensile intensity tested at 7, 14, and 28 durations. The workability and density of concrete reduce as the percentage replacement increases and the maximum reduction are (25 and 6.5%) respectively for (50%) glass aggregate replacement. The highest development in concrete compressive strength, flexural and splitting tensile intensity is (16.4, 14.7, and 15.1%) for 28 days of the glass aggregate percentage (20%) and the highest decrease is (3.4, 3.1, and 3.6%) for the percentage (50%).

Abstract: The aim of study is to produce durable structural concrete by using waste ceramics with specified type (white clay ceramics) as coarse aggregates in concrete. Mechanical properties were studied, the study also show good resistance to fire resistance for concrete contains ceramics as coarse aggregates compared with normal aggregates concrete, good mechanical properties such as compressive, tensile, and flexural strength. Results of study gave 17.5% increment in compressive strength by using 100% replacement of waste ceramic, flexural strength increased with 27.8% increment. Study also show less reduction in strength due to fire resistance by using waste ceramics compared to ordinary concrete, and also more durable concrete for salty water effects by using ceramic.

Abstract: Recently, the frame composite materials have been developed greatly at the production introduction level. The manufacturing technology of these materials is carried out in two stages: first, large aggregates are glued into the frame, and second, the porous frame voids are impregnated with the matrix component. In this article, we studied the various aggregates’ effect on the polymer concrete frame structures properties using epoxy binders. The materials based on the quenched cullet, brickbats, granite and limestone crushed stone, and the polymer granules were considered as large aggregates. The studied properties were the strength and elastic modulus. Quantitative dependences of compressive and bending strength, elastic modulus of frame composites on the aggregate type and other prescription factors are obtained. Using the methods of mathematical experimental planning, the optimal particle size distribution for the composites with grains from quenched cullet was selected. Particular attention should be paid to the possibility of using industrial wastes in polymer concrete compositions: polymer granules, quenched cullet and brickbats. Used glass makes up about 10% of the household waste. Its reuse is usually associated with high capital costs allocated for sorting glass by color, removing stones and other impurities. Glass grinding allows to get a fine-grained filler and aggregate. Strength and deformation characteristics of the matrix compositions, frameworks and composites as a whole are determined.

Abstract: The scientific article "Application of Modified Peat Aggregate for Lightweight Concrete" presents the results of studies of the properties of a new composite material for use in enclosing structures of residential and public buildings. Physical and mechanical characteristics of possible aggregates of local production for this type of concrete affecting its operational properties are considered. The prospects of using fly ash as an additive improving the characteristics of polystyrene concrete with the addition of modified peat have been established. The analysis was made and the optimal compositions for obtaining lightweight concrete based on peat and polystyrene foam were selected. The desorption properties of lightweight concrete important for its effective operation as a wall material were tested. It was found that the use of new types of surfactants can improve the water wettability of peat particles and polystyrene granules, thereby reducing the water-cement ratio and improving the compressive strength of the material. Possible efficiency of application of this type of concrete for use in enclosing structures of buildings and constructions under construction in seismic regions of Russia is considered. The presence of damping effect manifested in the material due to the presence of polystyrene granules in the perception of a certain level of load, which is important for the work of concrete under seismic influences, was experimentally established.

Abstract: Abrasion is the physical wear of a surface due to cyclically recurring dynamic forces and shifts. Therefore, abrasion resistance can be defined as the ability of a surface to resist wear due to friction. The paper deals with the issue of the resistance of concrete surface layers to the effects of abrasion. The research focused on monitoring the influence of different types of aggregate on increasing the abrasion resistance of concrete surfaces. Concrete surfaces with three different types of aggregate were tested: amphibolite, granodiorite and psammite. The concrete class was C35/45. Abrasion was tested using the Böhme method. The highest abrasion resistance after 28 days of maturation was found in concrete surfaces with amphibolite aggregate.

Abstract: This document deals with study of nanoand micro particles of artificial corundum in cement mixtures. This inert material with high hardness is usually used as fine-grained additions of concrete mixture. The most important characteristic of corundum is very high hardness (number 9 on Mohr scale). That is the reason, why is mostly added to the cement mixture primary intended for high load flooring. In this paper were studied several type of recycled corundum classified due to its origin. Because it is a recycled material, it was necessary to first examined basic physical properties such as chemical composition or granulometry. We have applied this fine grain material to cement mixes and compared their mechanical properties. For comparison measurement were used a mixture without this admixture and mixture with a corundum with similar granulometry but non-recycled origin.

Abstract: Materials play a fundamental role in any branch of civil engineering. From ancient times to the present day, society has required enormous amounts of construction materials, which implies an excessive exploitation of materials that come directly from nature. This paper explains the main differences, similarities, benefits and characteristics of the 2 designs of asphalt mixtures by means Marshall methodology. The first design is for control mixture, which was elaborated with a conventional asphalt AC-20 and 100% of natural aggregate (NA). The second design is for asphalt mixture with 30% of recycled concrete aggregate (RCA) and 70% of NA. Finally, it was determined that both designs have similar characteristics, which indicates that the use of 30% RCA in asphalt mixtures is adequate. In addition, it represents economic and environmental savings.