Aggregate Mixture Research Articles

Mechanical Properties of Unbound Perlis Limestone and Granite Aggregate Mixture for Road Application

The most important component of road construction is aggregate. As 70–80 percent of aggregates are used in road construction, the majority of aggregates used in Malaysia’s road construction are granite aggregates. Due to the lack of substitutes for aggregates and the rise in demand, this may hinder the development of the road construction process. This research seeks to identify high-quality alternatives to granite aggregate that can be utilised to their full potential. Since there is no granite in Perlis, Malaysia, the mechanical properties of the Perlis limestone aggregates were evaluated to ensure that they can be used alone or in combination with granite aggregates in road construction. The AIV, ACV, and LAA tests were conducted on both individual samples of Perlis limestone and granite aggregate, as well as combinations containing various percentages of each. In all tested parameters, the results indicated that Perlis limestone aggregates were superior to granite aggregates. In addition, when Perlis limestone and granite were combined in an unbound state with the presence of limestone, the strength and resistance to abrasion and impact increased linearly. It is believed that incorporating Perlis limestone into unbound layers of road construction, such as roadbase and subbase, will enhance their performance.

Modelling the effect of concrete cement composition on its strength and failure behavior

Typical concrete is a mixture of Portland cement, water, and aggregates. While aggregates have a substantial effect on the concrete strength and fracture behavior, the focus of the present study is on the hardened cement paste which can be further divided into the unreacted core, inner and outer products. In high strength concrete, water-to-cement ratio is low, and thus the distance between cement particles is small. Also, the amount of unreacted (high strength) core is higher, and the porosity is low. When water-to-cement ratio is higher, both the distance between cement particles and the porosity due to capillary pores increases. In the present study, we develop a numerical model based on the embedded discontinuity finite elements to predict the effect of the water-to-cement ratio on the compressive fracture behavior of concrete. Representative 2D plane strain simulations demonstrate that the present method captures the major features of concrete fracture and, particularly, qualitatively predicts the known effects of the water-to-cement ratio on concrete compressive strength.

Recycled Aggregates from Ceramic and Concrete in Mortar Mixes: A Study of Their Mechanical Properties.

In recent decades, large amounts of construction and demolition waste (CDW) have been generated and accumulated throughout Europe, which is a challenge to manage and control nowadays. This work shows the results of a study carried out with samples of ceramic recycled aggregates (CRAs) and recycled concrete aggregates (RCAs) mixed with cement (C) in mortars. The main objective of this research is to demonstrate how, by adding CRAs and RCAs to a mixture of cement and natural aggregate (NA), it is possible to develop a high-strength mortar and achieve the best mixing ratio. To achieve these objectives, the characterization of the samples was initially carried out such as XRF, XRD and SEM. Next, tests were carried out on the products obtained, such as the consistency of the fresh mortar and the density of the specimens. Finally, a study of mechanical compressive strength was performed at 7, 28 and 200 days. The results show that although both CRAs and RCAs negatively affect the curing process of the specimens, it is possible to develop mortars with compressive strengths greater than 20 MPa. An obvious increase in mechanical compressive strengths was seen between 7 and 200 days of analysis. The results achieved in this research could be an important guide for the management of CDWs by local industries, thus favouring the development of the circular economy.

Performance enhancement of road base material using calcium carbide residue and sulfonic acid dilution as a geopolymer stabilizer

Alkali activated industrial waste/by-product geopolymers have recently gained extensive attention from researchers as a replacement for cement in concrete manufacturing. However, little attention has been given to their employment as a stabilizer of unbound granular base/subbase (UGB) materials in road construction. Stabilizing granular base materials with geopolymers is explored in this study. The investigated geopolymer is composed of calcium carbide residue (CCR), a waste product resulting from the manufacturing of acetylene gas, which activated by a linear alkyl benzene sulfonic acid (LABSA). Four proportions of sulfonic acid dilution ratios and seven solid/liquid (CCR/diluted LABSA) mixes were prepared. The unconfined compressive strength (UCS) of the mixtures was determined in the laboratory. The maximum UCS was achieved by blending a diluted LABSA of (300/1000) ml with a geopolymer (solid: liquid) blend proportion of (80%:20%) by the total weight of aggregate. Based on the results, aggregate mixtures of 2.5%, 5%, 7.5%, and 10% of geopolymer blend content were prepared to determine the maximum UCS value corresponded to the optimum geopolymer mixing ratio. This optimum geopolymer ratio was recommended at 7.5%, which was then exposed to different curing times and environmental conditions to explore the variation in UCS as well as the elastic modulus (E). In addition, Scanning Electron Microscopy (SEM) and Energy Dispersive X-ray Spectroscopy (EDX) measurements revealed that the stabilized aggregate contained geopolymer gels generally produced microstructures that are more uniform and denser than the untreated aggregate structure. A blend of CCR and LABSA can be used as a feasible and sustainable eco-friendly alternative as a stabilizing agent for UGB in pavement engineering applications.

Comparison of Coronal Discoloration Induced by White MTA and CEM Cement

Coronal discoloration of endodontically treated teeth is a challenge in clinical dentistry. This study aimed to compare coronal discoloration induced by White Mineral Trioxide Aggregate and Calcium-enriched mixture cement. Fifty single-rooted, unrestored premolar teeth extracted for orthodontic reasons were selected. After access cavity preparation, all the root canals were instrumented with MTWO rotary files up to #40.6%. The specimens were randomly assigned to two experimental groups, White Mineral Trioxide Aggregate and Calcium-enriched mixture cement groups (n = 20), and two control groups (n = 5). In the White Mineral Trioxide Aggregate and Calcium-enriched mixture cement groups, the material was condensed via the access cavity 3 mm below the cementoenamel junction to a thickness of 3 mm. Tooth color was assessed using computer analysis of digital images. Tooth color measurements were recorded at eight time intervals: before material placement (but after tooth preparation), at 24 h, 48 h, one week, two weeks, four weeks, eight weeks, and sixteen weeks after material placement. Data were analyzed using t-test, ANOVA, repeated measure ANOVA, and Tukey HSD tests. The significance level was set at 5% for all the tests. Cervical discoloration of teeth in both experimental groups significantly increased over time (p < 0.05). However, samples in the White Mineral Trioxide Aggregate group showed more discoloration in cervical regions than Calcium-enriched mixture cement specimens after two, four, eight, and sixteen weeks (p < 0.05). Applying both White Mineral Trioxide Aggregate and Calcium-enriched mixture cement induced coronal discoloration; however, White Mineral Trioxide Aggregate samples exhibited greater cervical discoloration than Calcium-enriched mixture cement specimens after two, four, eight, and sixteen weeks.

Study of Mechanical and Thermal Properties for Epoxy Grouts Subjected to Seawater Conditioning at Elevated Temperature: Tensile Test and Compressive Test

Pipelines and risers are major transportation of oil and gas. These components are often exposed to extreme marine environmental conditions that can cause pipelines to fail due to corrosion. Hence, epoxy grouts are used as a coating material on the surface of pipelines and risers for supporting the pipe structure and corrosion prevention. In this case, the efficiency of epoxy grout is important in pipeline rehabilitation. Research on the adaptation of seawater, temperature, and epoxy grouts is carried out to determine the changes in mechanical and thermal properties of the material. The preparation of epoxy grouts was prepared with a mixture of epoxy resins, epoxy hardeners, and aggregates. After the sample compounds have been flattened, the mixture will be put into the mold. The seawater aging process was performed for seven days before conducting laboratory experiments. After the seawater aging process, there were physical changes on the surface of the epoxy grouts which are the epoxy grout become harder and there were voids that can act as stress concentration points that may cause micro-crack on the specimen. Next, tensile (ASTM 638) experiments were performed at different temperatures of 27°C, 40°C, 52°C, 72°C, 80°C and 100°C while the result of compression experiment is based on the literature critique of past journals. Based on the result, the young modulus and ultimate tensile strength of the epoxy grouts are decreased with increasing temperature. The increment of temperature causes the epoxy grouts to become weaker due to the changes in the polymer matrix structure of the epoxy grouts which lead to the failure at low load and shortens the life of the material. In addition, epoxy grouts are amorphous materials where the glass transition temperature determine the mechanical and physical properties of epoxy grouts. Therefore, the results of the study found that the epoxy grouts changed its mechanical properties from brittle to ductile when the temperature is at 72°C. From the comparison between samples immersed and not immersed in seawater, there is a decrease in Young’s modulus, ultimate tensile stress and strain due to the effect of seawater reaction. In conclusion, the increment in temperature and seawater adaptation factors affect the strength and durability of epoxy grouts.

PERFORMANCE OF JUTE FIBER REINFORCED CONCRETE IN THE CONTEXT OF BANGLADESH

Concrete is a mixture made up of a proportional mixture of water, aggregate (sand or gravel), cement, and admixtures to impart advantageous properties. Despite its high compressive strength, concrete is fragile; compared to its compressive strength, its tensile strength is only about 10%, and it also has a low resistance to cracking, which restricts its application. Fiber-reinforced concrete, which combines concrete with fibrous material to solve these limitations, is a solution. Fiber-reinforced concrete (FRC) has emerged as a new sustainable material for a varied range of applications, including building pavements, huge industrial building floors, and runways. Natural fibers are used in contemporary technologies (jute fiber) and this study explores the use of non-metallic fibers (jute fiber) in concrete. The purpose of this article is to analyze the strength properties of non-metallic fibers in concrete and compare them to standard plain concrete specimens. When Jutes fiber is added to concrete, the compressive strength increases to a certain limit, increasing fiber content. In this study, chopped jute fibers were utilized to create an FRC material to see whether the 28-day strength could be improved. Mixing and casting issues were created by fiber clumping at high fiber concentrations. In this experiment, 10 mm and 15 mm long jute samples (0.1%, 0.2%, and 0.3%) of volumetric weight are mixed with concrete. The mix design followed the American Concrete Institute's recommendations (ACI, 211.1-91). The ratio of water to cement was 0.4. Compressive strength of the concrete decreases, also resulting in poor workability. When compared to ordinary concrete, the compressive strength of 28 days was improved by 64.34%, and the optimal content of jute was determined to be 0.1%. The compressive and tensile strength of the fiber was also affected by its length. The ductile behavior of the FRC improves as the fiber content increases. In this investigation, it was also discovered that the modulus of elasticity of FRC was increased when compared to ordinary concrete

Effect of High Strength Concrete Prepared from Recycled Aggregates on the Behavior of Reinforced Concrete Beams Under Flexure

Experimental study of the flexural implementation of high-strength reinforced recycled aggregate mixture is investigated for 100 × 150 × 1000 mm beams of reinforced concrete with different coarse recycled aggregate ratios plus three steel reinforcement ratio (ρ) casting and testing at 28 days. The aim of this research is to use coarse recycled aggregate ratios as a natural coarse aggregate replacement by (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%) in high strength concrete. Former investigations experiments have been carried out and provided on the characteristics of the mixture prepared with recycled aggregates, such as strength in compressive, workability, flexural tensile strength, and splitting tensile strength. Prism and cylinders have been prepared, and specimens have been tested at ages 7, 14, 28 days of curing. This investigation considers the flexural efficiency of reinforced recycled aggregate mixture beams in describe as cracking and ultimate flexural strength, and load-deflection correlation, the moment at mid-span, and ductility and failure modes. Results show that 100% recycled coarse aggregate degrades the concrete strength relevant to 18.0, 18.9, and 19.3%, 16.2, 16.6, and 19.4% and 16.0, 16.2, and 18.2% in expression of compressive, splitting and flexural strength with tensile for 7, 14 and 28 days, reduces the workability by 33.3% and decreases the cracking and ultimate load with the improved rate of recycled coarse aggregate regarding of 39.4 and 45.1% and 10.9% for ductility for the beams with ratio of reinforcement of ρ=0.0157%. Decreasing the reinforcement ratios with ρ=0.0105 and 0.0067% while keeping the strength of concrete constant 100% recycled coarse aggregate decreases the cracking and ultimate load of about 11.3 and 20.8% and 15.6 and 24.4% respectively and 2.0 and 4.3% for ductility.

Production and characterization of lightweight aggregates from municipal solid waste incineration fly-ash through single- and double-step pelletization process

The performance of a cold-bonding pelletization process was investigated for lightweight aggregates (LWAs) production from municipal solid waste incineration (MSWI) fly-ash (FA), by including multiple waste materials in the aggregate mixture. Before pelletization, FA was pre-treated by washing with water, which led to a reduction of chloride (66.79%) and sulphate (25.30%) content. This was further confirmed by XRF and XRD analyses, which showed a reduction of chloride elements and the content of chlorine crystalline phases. The pelletization process was carried out using both single- and double-step methods. For single-step pelletization, all the mixtures contained 80% FA, combined with various compositions of cement (5, 10, and 15%) and granulated blast furnace slag (GBFS) (5, 10, and 15%). For the double-step pelletization 30% of cement and 70% of marble sludge (MS) were added to each of the previous mixtures. The apparent density of all the aggregates varied between 1.60 and 1.87 g cm−3, suggesting their suitability to be classified as LWAs. Aggregates produced from double-step pelletization showed improved characteristics, with water absorption capacity and open porosity generally lower compared to the corresponding aggregates from the single-step pelletization. The best values of compressive (crushing) strength (almost 11 MPa) were observed for double-step pelletization aggregates with initial cement: GBFS mixture of 15%:5%. Results from leaching tests showed an overall significant release of chloride and sulphate. Nevertheless, leaching from double-step pelletization aggregates was reduced by 1.73-4.02 times for chloride and 1.58-5.67 times for sulphate, further suggesting that better performances are achievable through the addition of an aggregate second layer.

Pervious concrete as environmentally friendly materials-an overview

Pervious concrete contains a mixture of water, cement, coarse aggregates and little or no fine aggregates. Pervious concrete is increasingly known as an environmentally friendly material due to its usefulness in improving water quality by removing all suspended solid particles in the flood, reducing the flow of flood water, reducing the heat island effect and other environmental benefits. In this article, the results of valid research on the physical (slump, density, porosity, water permeability) and mechanical (compressive strength, flexural strength, splitting tensile strength) properties of Pervious concrete have been briefed and reported.

Do large‐scale associations in birds imply biotic interactions or environmental filtering?

AbstractAimThere has been a wide interest in the effect of biotic interactions on species' occurrences and abundances at large spatial scales, coupled with a vast development of the statistical methods to study them. Still, evidence for whether the effects of within‐trophic‐level biotic interactions (e.g. competition and heterospecific attraction) are discernible beyond local scales remains inconsistent. Here, we present a novel hypothesis‐testing framework based on joint dynamic species distribution models and functional trait similarity to dissect between environmental filtering and biotic interactions.LocationFrance and Finland.TaxonBirds.MethodsWe estimated species‐to‐species associations within a trophic level, independent of the main environmental variables (mean temperature and total precipitation) for common species at large spatial scale with joint dynamic species distribution (a multivariate spatiotemporal delta model) models. We created hypotheses based on species' functionality (morphological and/or diet dissimilarity) and habitat preferences about the sign and strength of the pairwise spatiotemporal associations to estimate the extent to which they result from biotic interactions (competition, heterospecific attraction) and/or environmental filtering.ResultsSpatiotemporal associations were mostly positive (80%), followed by random (15%), and only 5% were negative. Where detected, negative spatiotemporal associations in different communities were due to a few species. The relationship between spatiotemporal association and functional dissimilarity among species was negative, which fulfils the predictions of both environmental filtering and heterospecific attraction.Main conclusionsWe showed that processes leading to species aggregation (mixture between environmental filtering and heterospecific attraction) seem to dominate assembly rules, and we did not find evidence for competition. Altogether, our hypothesis‐testing framework based on joint dynamic species distribution models and functional trait similarity is beneficial in ecological interpretation of species‐to‐species associations from data covering several decades and biogeographical regions.

Development of a dry mortar with nanosilica and different types of industrial waste for the application in borehole heat exchangers

A geothermal borehole is a heat exchanger between the soil and a heat transfer fluid. This fluid flows throw in the geothermal pipes, which has been inserted into borehole. Using a Ground Source Heat Pump (GSHP) systems, the fluid provides heating and cooling buildings.The space between the geothermal pipes and the ground is filled with a geothermal backfill. This geothermal fill must be having high thermal conductivity for facilitate the heat flow. In this way this fill is an important element in a Borehole Heat Exchanger as its choice can result in significant economic and energy savings during the geothermal installation’s lifetime. However, in general it has not received enough attention.The geothermal backfill materials formed by a mixture of cement, fine aggregate, sand and/or additions are known as geothermal grouts. The aggregated additives and the other materials aggregated confers to the geothermal backfill high thermal conductivity. This property is rejected in the conventional grouts used in buildings.On the other hand, the use of industrial waste or by-products in geothermal grouts is considered more sustainable, for it reduces landfill volume and the need of exploiting new mineral resources.This paper describes the development of a geothermal grout, named MG 7. MG-7 has improved thermal properties compared with conventional grouts. In this case, mining and by-products from surrounding companies have been used, following the principles of the circular economy.To determinate the geothermal grout properties different techniques and conventional equipment has been used. However, to calculate the thermal conductivity a specific device developed by the authors. Finally, it has been obtained a pre-dosed geothermal grout with a thermal conductivity of 2.01 ± 0.08 W/m∙K (K = 2), in which 30 % of the aggregates come from industrial waste, such as mine tailings, ladle furnace slag, fly ash and silica fume. It also contains 2 % of silica nanoparticles.

Influence of technological parameters on the behaviour in operation of the asphalt milling equipment

Within the work will be studied, in particular, the aspects related to the mechanical stresses that manifest themselves at the level of the cutter teeth used to strip the worn asphalt clothing. Studies in the field have focused on the interaction between the teeth of the milling drum and the asphalt clothing. The literature provides information and results focused, especially, on the aspects related to the way in which the dislocation of the asphalt concrete components occurs (the mixture of aggregates and filler / bitumen in solid state) under the action of the milling tooth. The authors present a method of simulating (using the combination of FEM-DEM numerical methods) of the cutting process by which it is ensured the highlighting of the developed tensions at the level of the active part of the tooth. In this way, it is attempted to bring to the fore the operating conditions specific to the milling equipment and to identify how they influence the interaction between the asphalt and the active part of the cutter teeth.

Classify Aggregate In Asphalt Pavement Layers (A.C-B.C) using Sieve Shaker

Aggregates are a significant feature of asphalt mixtures, which significantly affect the volumetric properties and mechanical performance. Layers of concrete asphalt consist of a mixture of fine aggregates, coarse aggregates, and fillers mixed with penetration grade asphalt. The concrete pavement layer (asphalt concrete) has several types: wear surface layer, intermediate surface layer, and foundation layer. The experimental research method with the gradation testing method using the Sieve Shaker machine with aggregate objects. The aggregate used in the form of fine aggregates from Lumajang sand and coarse aggregates from Kediri Kediri is taken randomly with a maximum size of 2.36 mm, aggregate used in the form of corals originating from Kedak area, Semen Subdistrict, Kediri Regency with a maximum size of 19mm. This study aimed to determine the feasibility of aggregate classification in the classification of road pavement layers. The study was conducted using the Sieve Shaker machine with reference to the AASHTO T27. This study obtained the results that the aggregates tested from the Kedak, Kediri, and Pasir Lumajang regions deserved to be included in the Asphalt concrete A.C-B.C category in accordance with Bina Marga Division 6.

Effect of High Strength Concrete Prepared from Recycled Aggregates on the Behavior of Reinforced Concrete Beams Under Flexure

Experimental study of the flexural implementation of high-strength reinforced recycled aggregate mixture is investigated for 100 × 150 × 1000 mm beams of reinforced concrete with different coarse recycled aggregate ratios plus three steel reinforcement ratio (ρ) casting and testing at 28 days. The aim of this research is to use coarse recycled aggregate ratios as a natural coarse aggregate replacement by (0, 10, 20, 30, 40, 50, 60, 70, 80, 90, and 100%) in high strength concrete. Former investigations experiments have been carried out and provided on the characteristics of the mixture prepared with recycled aggregates, such as strength in compressive, workability, flexural tensile strength, and splitting tensile strength. Prism and cylinders have been prepared, and specimens have been tested at ages 7, 14, 28 days of curing. This investigation considers the flexural efficiency of reinforced recycled aggregate mixture beams in describe as cracking and ultimate flexural strength, and load-deflection correlation, the moment at mid-span, and ductility and failure modes. Results show that 100% recycled coarse aggregate degrades the concrete strength relevant to 18.0, 18.9, and 19.3%, 16.2, 16.6, and 19.4% and 16.0, 16.2, and 18.2% in expression of compressive, splitting and flexural strength with tensile for 7, 14 and 28 days, reduces the workability by 33.3% and decreases the cracking and ultimate load with the improved rate of recycled coarse aggregate regarding of 39.4 and 45.1% and 10.9% for ductility for the beams with ratio of reinforcement of ρ=0.0157%. Decreasing the reinforcement ratios with ρ=0.0105 and 0.0067% while keeping the strength of concrete constant 100% recycled coarse aggregate decreases the cracking and ultimate load of about 11.3 and 20.8% and 15.6 and 24.4% respectively and 2.0 and 4.3% for ductility.

Influence of the Aggregate Shape and Resistance to Fragmentation on Unbound Base Layer Resilient Modulus

The performance of unbound base materials, exclusively of the upper base layers, besides compaction level and layer thickness, depends on unbound material type, aggregates shape, fine content and mechanical properties of aggregates. The response of the pavement structure to loading is expressed through stress and strain magnitudes, accumulation of which leads to layer permanent deformations. One of the key factors for designing unbound base layers is resilient modulus, which can be found from triaxial tests. The aim of the research is to analyse the effect of the aggregate particle shape, structure and the resistance to crushing properties on resilient modulus of the upper layers of the unbound base layers. The following properties have been determined during the tests: aggregate particle size distribution, particle shape and flakiness, percentage of crushed and broken particle surfaces, density, water absorption, resilient modulus under low stress level loading. According to the performed research with tested aggregate mixtures, it is assumed that most influence on resilient modulus is exerted by aggregate whole granular size distribution, water absorption and the largest aggregate particle surface angularity. Resilient modulus in the tested dolomite fraction mixtures differing from 32 mm to 56 mm showed any reasonable difference with mean nominal pressures being higher than 300 kPa.

Investigation of the Effect of Yarn Waste Fibers and Cocamide Diethanolamide Chemical on the Strength of Hot Mix Asphalt

In this study, conventional bitumen test were performed on bituminous binder modified with Cocamide Diethanolamide chemical at different ratios. According to results of tests, the most suitable additive ratio has been determined as 5%. However, it was concluded that indirect tensile strength and resistance to moisture of samples prepared with bituminous binder modified with 5% Cocamide Diethanolamide has been adversely affected. It was desired to investigate that whether these properties could be strengthened by yarn waste fibers. Firstly, the effect of 0.1%, 0.2% and 0.3% yarn waste fibers on samples prepared with reference bituminous binder was investigated. Obtained results showed that both indirect tensile strength and resistance to moisture of samples containing 0.1% yarn waste fiber increased. Therefore, 0.1%, 0.2% and 0.3% yarn waste fibers were added to the aggregate mixture and mixing of them with bituminous binder modified with 5% Cocamide Diethanolamide were provided. According to obtained results, different ratios of yarn waste fibers added to aggregate mixture did not have a positive effect on moisture sensitivity. Tensile strength ratio values of samples containing bituminous binder modified with 5% Cocamide Diethanolamide and yarn waste fibers added to the aggregate mixture did not provide specification limit.

Small soluble α-synuclein aggregates are the toxic species in Parkinson’s disease

Soluble α-synuclein aggregates varying in size, structure, and morphology have been closely linked to neuronal death in Parkinson’s disease. However, the heterogeneity of different co-existing aggregate species makes it hard to isolate and study their individual toxic properties. Here, we show a reliable non-perturbative method to separate a heterogeneous mixture of protein aggregates by size. We find that aggregates of wild-type α-synuclein smaller than 200 nm in length, formed during an in vitro aggregation reaction, cause inflammation and permeabilization of single-liposome membranes and that larger aggregates are less toxic. Studying soluble aggregates extracted from post-mortem human brains also reveals that these aggregates are similar in size and structure to the smaller aggregates formed in aggregation reactions in the test tube. Furthermore, we find that the soluble aggregates present in Parkinson’s disease brains are smaller, largely less than 100 nm, and more inflammatory compared to the larger aggregates present in control brains. This study suggests that the small non-fibrillar α-synuclein aggregates are the critical species driving neuroinflammation and disease progression.

Experimental Study of Concrete Making Using Recycled Coarse Aggregate

Concrete is a form of construction in the form of a composite material consisting of a mixture of fine aggregate, coarse aggregate, cement, and water. However, in certain cases, the concrete application is often a problem, especially the lack of a minimal amount of coarse aggregate material, increasing material prices. Recycled concrete aggregate (RCA) is an embodiment of concrete composed of recycled materials. Recycled material is obtained from fragments or remnants of the demolition of unused concrete. The method used to make concrete from the constituent materials using concrete waste as coarse aggregate per the rules of science is experimental. The tests are the aggregate moisture content test, the mud content test, the coarse aggregate abrasion test, the slump test, and the concrete compressive strength test at 28 days of treatment. The compressive strength results showed that the normal concrete sample could reach FC 18.53 MPa. The concrete sample using recycled coarse aggregate reached FC 23.79 MPa, so using recycled materials for manufacturing concrete can achieve the planned target

Investigations of Properties of Soil-Aggregate Mixtures

The subject of this paper is the evaluation of the use of waste material, which is the native soil. On the example of the base ground taken from the village of Lipie (Podkarpackie voivodeship), soil-aggregate mixtures were prepared with a different degree of addition of natural aggregate. The study analysed the quantitative and qualitative parameters of the prepared mixtures and assessed their physical and mechanical properties to determine their suitability for the construction of nfrastructural facilities. It should be noted that most specifications recommend the use of primarily aggregate mixtures. The paper presents the results of a study analysing the effect of aggregate admixture to the native soil on selected physical and strength properties of the mixtures developed. The obtained results confirmed the validity of research on the use of soil-aggregate mixtures for construction purposes.