From lab testing it was found that, the density of. Enhancement of properties of recycled coarse aggregate. Examples of classes of concrete aggregate are shown below. Aggregates types of aggregates coarse aggregate, fine. Recycled concrete as aggregate for structural concrete production. Rcas porous network has influenced physical properties, such as capillary absorption of water and the porosity accessible to water. Close to half of the coarse aggregates used in portland cement concrete in north america are gravels. Currently, only the use of coarse aggregate derived from construction or. The coarse aggregate particles are usually crushed.
Natural sand, crushed stone dust or manufactured sand by crushing rock. The main objective of this study was utilization of marble waste. Mix proportions in order to investigate properties of cs concretes, six mixes were employed. In this paper, c25 waste road concrete is used as an experimental material, the uniaxial compression strength and tensile splitting strength of c25 rac whose coarse aggregate replacement rate is 0%, 25%, 50%, 75%, and 100% are tested under the condition that the watertocement ratio is 0. Two different arrangements have been used to determine the shear. Depending on composition, shape, size and other properties of fine aggregate you can have a significant impact on the output. Fine coarse salts artificial aggregate maximum size toughness wear permeability coarse aggregate mineral composition particle shape surface characteristics organic impurities gradation soundness chemical activity physical properties specific gravity hardness thermal properties absorption elastic properties cement solutions water retentivity.
The methodology for determining the fractional parts of an aggregate particle, pores versus solids and interstitial voids in the bulk volume are shown. Aggregates coarse aggregates 5 mm fine aggregates properties of aggregates must be known before mixing concrete to obtain a desirable mixture. The role of fine aggregate can be described in few points. Their wet to dry strength variation needs to be small. The size of aggregate used may be related to the mix proportions, type of work etc. Difference between fine and coarse aggregate civil engineering. The standard testing procedure for this is the american society of testing. Effects of aggregate size, shape, and surface texture on the. For recycled coarse aggregate, the parent concrete is crushed through a mini jaw crusher maintaining the size of aggregate between 20 and 4. Each material was characterized for physical and chemical properties in accordance with the appropriate astm standards. If they are to be used in concrete, they should not react with the alkaline environment of the concrete. Kaplan 1959 studied the effects of the properties of coarse aggregates on.
Although some variation in aggregate properties is expected, characteristics that are. He also pointed out that coarse aggregate bituminous concrete, where little or no gradation control of the aggregate was attempted, has performed well for 20 years. The cf and 818 charts for the wg and nwg combined aggregates are plotted in fig. Aggregates are available in nature in different sizes. Rashid, debashis mallick and tozammel haque department of civil engineering, khulna university of engineering and technology, khulna, bangladesh email. Pdf assessment of properties of recycled coarse aggregate. Testing of properties of cement, fine aggregate, coarse aggregate and coconut shells.
Pdf assessment of physical properties of coarse aggregates in. Easting quantity of cement, fine aggregate, coarse aggregate, coconut shells required for the experimental work. Concrete is by far the most versatile and most widely used construction material worldwide. Materials utilized for this project consisted of cfa, cement, fine aggregate, coarse aggregate, and coal fly ash. Test and analyses has been carried out to establish relationships among the compressive strength, split tensile strength and shear strength of concrete using recycled coarse aggregate. For the preparation of economical concrete mix on should use largest coarse aggregates feasible for the structure. The nwg aggregates were developed by combining different proportions of size number 57 coarse aggregate and fine aggregates. The properties of the coarse aggregate used in a concrete mixture affects the modulus for a few reasons.
Aggregates are divided into two categories from the consideration of size i coarse aggregate and ii fine aggregate. Concrete 1 concrete a composite material that consists essentially of a binding medium, such as a mixture of portland cement and water, within which are embedded particlesorfragmentsofaggregate,usuallyacombination of. Properties of aggregates construction aggregate porosity. Coarse aggregates in high strength concrete given the critical role that the interfacial transition plays in highstrength concrete, the mechanical properties of coarse aggregate will have a more pronounced effect than they would in conventionalstrength concrete. The gradation, particle shape and texture of the coarse aggregate along with fineness modulus of the fine aggregate will.
Aggregate particles have certain physical and chemical properties which make the aggregate acceptable or unacceptable for specific uses and conditions. The current manuscript presents a detailed study on physical properties of aggregates procured from all seventeen districts in gujarat. To establish suitability for use in agency concrete, mndot performs concrete aggregate property testing on fine and coarse aggregate sources in accordance with mndot specifications 3126, 31 and 37. Sep 03, 2017 the final properties of the concrete will depend on the cement characteristics, the type and amount of aggregate, the watercement ratio, and the completeness of the reaction subject to time, humidity, and temperature. Properties of aggregates also has effect on resulting concrete. As a result of the depletion of natural sources of coarse aggregates and lack. Pdf comparison of properties of coarse aggregate obtained from. Production of mix normal concrete of grade m 20 in the. The following tests are required for basic understanding of aggregate properties.
This bulletin describes types of aggregates normally used in concrete, aggregate properties affecting performance of the concrete, tests used to measure aggregate properties, and. Coarse aggregates are mainly used in concrete, railway track ballast, etc. Using rcas affects mechanical properties of concrete, whether compressive strength or splitting tensile strength. It is well recognized that coarse aggregate plays an important role in concrete. Onefourth of the minimum dimension of the concrete member. Some natural aggregate deposits, called pitrun gravel, consist. Coarse aggregate acts as inert filler material for concrete. Experimental investigation of concrete using coconut shell as. The purpose of the fine aggregate is to fill the voids in the coarse aggregate and to act as a workability agent. Physical properties of fine and coarse aggregate uwm. Fine aggregates are used in mortar, plaster, concrete, filling of road pavement layers, etc. Effects of aggregate types on thermal properties of concrete milon k. This paper presents the results of an experimental investigation into the effects of high temperatures on the properties of concrete made with crushed clay bricks as the coarse aggregate. Aggregate sampling aashto t 2 sample preparation aashto t 248 aggregate gradation of both fine and coarse aggregates aashto t 27 wash loss determination of minus no.
Is456 suggests following recommendation to decide the maximum size of coarse aggregate to be used in p. Griffith and kallas 11, from a study of crushed and uncrushed coarse and fine aggregates, found that the relative proportions of coarse and fine aggregate for maximum. The lower percentage of fine to total aggregate provides an increase in compressive strength at the expense of workability. As expected, a lightweight aggregate will have a lower modulus than. The main purpose of this work is to determine the basic properties of rac depending on the coarse recycled aggregate content, and to compare them to the properties of concrete made with natural aggregate naccontrol concrete. Source of aggregates, density and porosity water absorption of a1 and a2 coarse aggregates were kept constant. Gravels constitute the majority of coarse aggregate used in concrete with. A higher aggregate modulus will result in a concrete having a higher modulus. Mechanical and durability properties of concrete based on. One property is the modulus of elasticity of the coarse aggregate. Comparison of properties of coarse aggregate obtained from recycled concrete with that of conventional coarse aggregates. In addition, their differences primarily depend on the. Material passing 75 m sieve should not be 4% by weight. Aggregate particles have certain physical and chemical properties which make the aggregate acceptable.
Coarse aggregate typically occupies over onethird of the volume of concrete, and research indicates that changes in coarse aggregate can change the strength and fracture properties of concrete. Influence of crushed coarse aggregates on properties of concrete. Properties of concrete with coconut shells as aggregate. The detailed data on properties of these materials are reported elsewhere 14. Physical properties the physical properties of aggregates are those that refer to the physical structure of the particles that make up the aggregate. Aggregate properties significantly affect the workability of plastic concrete and also the durability, strength, thermal properties, and density of hardened concrete. Nov 10, 2017 they need to be stable so as to not degrade in either the short or long term. This waste is dumped on to open land which creates a lot of environmental problems. The aggregates are usually washed and graded at the pit or plant. Properties of concrete with coconut shells as aggregate replacement 22 2. Classification of aggregates based on size and shape coarse. Fine aggregates are the structural filler that occupies most of the volume of the concrete mix formulas. The voids between the coarse aggregate are filled up by fine aggregate.