Recycled aggregates in concrete aggregate research. Pdf compressive and flexural behaviour of recycled aggregate. A new mechanical model for analysing the behaviour of axially loaded recycled aggregate concrete filled steel tubes racfsts stub columns is presented in this study. Magazine of concrete research, volume 64, issue 7, 1 jul 2012 617630 flexural performance of concreteencased concretefilled steel tubes authors. Aggregates provide bulk, strength, and wear resistance in these applications.
To study the seismic strength and stiffness for recycled aggregate concrete filled steel tube racfst frame, twoframe specimens made up of racfst column and reinforced recycled aggregate concrete rac beam were used for a seismic test under reversed lowcycle loading. The failure mechanism, hysteresis curve, strength attenuation, and stiffness degradation were determined for the specimens. Recycled concrete is created by breaking, removing, and crushing existing concrete to a preferred size. Results showed that the use of recycled aggregates has an adverse effect on the workability of concrete.
Broken concrete that is carefully laid creates a stable, porous traffic surface that rainwater can filter through. Most painted concrete can be used for these purposes in accordance with rule exemptions. Based on the studying of the physical and mechanical properties of recycled coarse aggregate, the mechanical property of recycled aggregate concrete rac with five concrete mixes with 0%, 25%, 50%, 75% and 100% rca respectively are prepared. Behavior of compound concrete filled reinforced pvc tubes. Such an effect can be easily retained by using plasticizers. Behavior of normalstrength recycled aggregate concrete.
Request pdf on dec 9, 2015, tianyu xie and others published behavior of recycled aggregate concretefilled basalt and carbon frp tubes find, read and cite all the research you need on researchgate. The application of recycled aggregate has been started in many construction projects in many european, american and asian countries. Replacement of recycled coarse aggregates with natural. Nov 15, 2014 it is called recycled aggregate which can be produced by concrete crusher. The compressive strength of recycled coarse aggregate rca is found to be higher than the compressive strength of normal concrete when used upto a certain %. In view of the advantages of concrete filled steel tubular columns, recycled aggregate concrete filled steel tube racfst, in which the natural aggregates are. It was found that rac had lower compressive strength compared to natural. Recycled concrete aggregate, also known as rca, is an extremely popular replacement for natural stone aggregates. Theoretical analysis on mechanical behavior of axially loaded. The aggregates are categorized by size as coarse and fine aggregate. This fact sheet explains when painted concrete is considered clean and is exempt for use vs.
On average, the compressive strength of the standard cubes 16 of the recycled. Request pdf on dec 9, 2015, tianyu xie and others published behavior of recycled aggregate concretefilled basalt and carbon frp tubes find, read. Impact response of recycled aggregate concrete filled. It is called recycled aggregate which can be produced by concrete crusher. In this study we replaced natural aggregates with recycled aggregates in concrete cubes.
Keywords concretefilled steel tube cfst, recycled aggregate. Comparative environmental assessment of natural and recycled aggregate concrete. Comparative environmental assessment of natural and. The model is derived from the typical elastoplasticity, the nonlinear elastic mechanics, and the properties of materials. Paper open access study on recycled concrete powders as. This study experimentally explores the behaviour of recycled aggregate concrete filled steel tubes racfst subjected to axial compression loading. Such composite members are normally called as recycled aggregate concrete filled steel tubes racfst. Construction materials are increasingly judged by their ecological characteristics. This research also covered rac mixtures at different watercement ratio 0. Aggregate ra on compressive strength of recycled aggregate concrete rac were investigated.
Keywords concrete filled steel tubes recycled aggregate concrete columns expansive agent eccentric load corresponding authors. Structural behaviour of composite members with recycled. Research on the bond behavior of preplaced aggregate concrete. Replacement of recycled coarse aggregates with natural coarse.
Construction and demolition waste recycling a literature. Flexural strength properties of recycled aggregate concrete. Abstract concrete filled steel tubes cfst were used from the early 1900s in the construction. Once encased inside steel tubes, the requirements on the mechanical capability and durability of the recycled concrete can be relatively relaxed, which considerably eases the production process and reduces the cost for rac. The characteristic of recycled aggregates could be different by its parent concrete because the parent concrete was designed for its purposes such as permeable, durable and high strength concrete. Compressive strength characteristics of concretefilled. The results show that the recycled aggregate concrete may degrade the concrete strength during the curing period for the. Recycled aggregate in concrete linkedin slideshare. Experimental behaviour of recycled aggregate concretefilled.
This paper presents the results of an experimental study on the axial compressive behavior of concrete filled frp tubes cffts, prepared using different amounts of recycled concrete aggregate rca. Experimental behaviour of recycled aggregate concrete. The failure mechanism, hysteresis curve, strength attenuation, and stiffness degradation were. Construction aggregates make up more than 80 percent of the total aggregates market, and are used mainly for road base, riprap, cement concrete, and asphalt. Rca is usually made up of old concrete from sidewalks, pavements, curbing and building slabs. Apr 15, 2015 this is a comparative study on conventional concrete and recycled aggregate concrete. The percentages of replacement will be 0%, 50% and 100%. The compressive strength of recycled aggregate concrete. Materials 2020, 2114 3 of concrete scc for di erent levels of recycled aggregates ra. Use of recycled aggregate in concrete can be useful for environmental protection and economical terms.
Recycled concrete can be used in many of the same ways as you would use new materials, such as gravel, paving materials, and aggregates. However, detail research over the cfst did not begin until. The loading rate applied to the steel tubes filled by rac. Abstract the aim of this research work is to gain a deep insight and understanding into the impact response of the recycled aggregate and normal aggregate concrete filled steel tube racfst and nacfst columns strengthened with carbon fibre reinforced plastic cfrp. Compound concretefilled steel tubular ccfst columns further improve the efficiency with which dcls are used due to the advantages of concretefilled steel. The uniaxial mechanical behavior, flexural performance, creep performance as well as eccentric loaded behavior of racsft specimens were discussed. The recycled coarse aggregates are obtained from the earthquake waste in sichuan. Theoretical analysis on mechanical behavior of axially. Structural behaviour of recycled aggregate concrete. After being compiled the concrete is processed and screened, which includes crushing the concrete into smaller pieces. Lightweight concrete cast using recycled aggregates. The ratio of the outer diameter to thickness of steel tube. Article information, pdf download for experimental performance of recycled aggregate.
This study experimentally explores the behaviour of recycled aggregate concretefilled steel tubes racfst subjected to axial compression loading. Compressive and flexural behavior of recycled aggregate concrete filled steel tubes racfst under shortterm loadings. This paper presents the experimental results of recycled aggregate concrete filled steel tube columns prepared with different amount of recycled coarse aggregate rca subjected to axial loading. Numerical analysis of recycled aggregate concretefilled. Creep behavior of concrete using recycled coarse aggregates. Behaviors of recycled aggregate concretefilled steel. Concrete shrinkage and creep in recycled aggregate concrete. Influence of amount of recycled coarse aggregate on. Permeable paving for walkways, driveways, and other outdoor hard surfaces.
The effects of steel tube dimensions, shapes and the confinement of concrete. Behaviour of recycled aggregate concrete filled stainless. Properties of recycled aggregate concrete filled steel tubes. Based on the mechanical model, a novel numerical program is developed. Structural behaviour of recycled aggregate concrete filled. Review article assessment of recycled aggregate concrete. The beams and columns of the frame were made of recycled aggregate concrete filled square steel tube. Based on the studying of the physical and mechanical properties of recycled coarse aggregate. It also includes an investigation on the compressive behaviour of racfst and nacfst columns.
In these mixes, natural coarse aggregate was partly or totally replaced by recycled aggregates. Thirteen specimens with circular section, including 10 racfilled. There is, therefore, considerable incentive to develop alternative aggregate sources based on waste materials. Figure 3 shows the particle size distribution curve of the coarse aggregates in recycled concrete aggregate rca. Timedependent behaviour of 100% recycled coarse aggregate.
Compressive and flexural behaviour of recycled aggregate concrete filled steel tubes racfst under shortterm loadings. Pdf behaviour of recycled aggregate concrete filled stainless steel. Seismic strength and stiffness for recycled aggregate. For comparison purpose, tests were also performed on 12 normal concretefilled steel tube ncfst specimens, three steel tubes and one specimen of. The rate of replacement of the recycled coarse aggregate was 100%. Recycled concrete can be used as aggregate in new concrete, particularly the coarse portion. This is a comparative study on conventional concrete and recycled aggregate concrete. Magazine of concrete research, volume 68, issue 6, 1 mar 2016 271282 flexural performance of concreteencased concretefilled steel tubes authors. Behaviors of recycled aggregate concretefilled steel tubular columns under eccentric loadings. International journal of concrete structures and materials vol. Here we are trying to see a pattern of how the strength decrease once we replace natural coarse aggregate nca with recycled coarse aggregates rca.
Pdf past research indicates that recycled aggregate concrete rac. The concrete industry makes up approximately 30% of the total market for aggregates and it is estimated that 165 million tonnes are used annually in concrete. A low cyclic loading test of six frame specimens was carried out. Analysis of recycled aggregate concrete filled steel tube. This method is being developed in germany to encourage the use of recycled concrete and other aggregates in the production of new.
For comparison purpose, tests were also performed on 12 normal concrete filled steel tube ncfst specimens, three steel tubes and one specimen of recycled aggregate concrete. Research article theoretical analysis on mechanical behavior. Research article theoretical analysis on mechanical. Proceeding of the 6th international symposium on tubular structures, melbourne, australia, 1994, 293298.
This paper presents the results of an experimental study on the axial compressive behavior of concretefilled frp tubes cffts, prepared using different amounts of recycled concrete aggregate rca. In order to research the interface bondslip behaviors of recycled aggregate concrete filled square steel tube racfsst, ten specimens using waste concrete were designed for launch test. Mod01 lec33 using recycled aggregates in concrete construction duration. Recycled aggregates are the materials for the future. An equivalent stressstrain model is proposed to simulate the behavior of the recycled aggregate concrete confined by a steel tube. Herein, the specimens are called fj1, fj2, fj3, fj4, fj5 and fj6, while the design parameters for the specimens are presented in table 1. However, the ultimate strength and stiffness 90day curing period for the square and circular solid steel tubes. The flow chart of the experimental program the ordinary portland cement, graded sand and coarse aggregates with addition of an addipor55 as 0, 10, 20 and 30% of coarse aggregate volume were used.
In view of the advantages of concrete filled steel tubular columns, recycled aggregate concrete filled steel tube racfst, in which the natural aggregates are partly or totally replaced by the recycled aggregates. Compressive and flexural behaviour of recycled aggregate. The results show that the the content of sio2 in recycled concrete powder is more than cement and fly ash. Bashandy et al lightweight concrete cast using recycled aggregates figure 2. Mixes with 10%, 30%, 50% and 100% by volume replacement of fine natural aggregates fna with fra were produced and tested for water. The replacement rate of rcp has little influence on the slump of fresh recycled concrete compared to fly ash. Concrete filled steel tubular cfst columns are an effective means to improve the mechanical properties of concrete. Recycled aggregatesprofitable resource conservation. A nonlinear finite element model for the square recycled aggregate concrete filled steel tube stub column under axial compression has been developed using the generalpurpose finite element program.
The fra used come from demolished concrete of known properties. Yang yf, han lh 2006 compressive and flexural behaviour of recycled aggregate concrete filled steel tubes racfst under shortterm loadings. Yang yf 2011 behaviour of recycled aggregate concretefilled steel tubular columns under longterm sustained loads. Twentyfour racfst specimens were tested to failure. Roederc,jimad a key lab of structures dynamic behavior and control of the ministry of education harbin institute of technology, harbin 150090, china.
Behaviors of recycled aggregate concretefilled steel tubular. Later, recycled aggregates were introduced in concrete mixes. Impact response of recycled aggregate concrete filled steel. Recycled aggregates consist mainly of crushed concrete and crushed asphalt pavement. Behavior of recycled aggregate concretefilled basalt and. The binder content was kept constant for all concrete mixtures, with a water to binder ratio wb of 0. Thirtysix cffts were tested under axial compression. Ra is used to replace natural aggregate na as coarse aggregate in concrete mixes. Marinkovic s1, radonjanin v, malesev m, ignjatovic i. A nonlinear finite element model for the square recycled aggregate concretefilled steel tube stub column under axial compression has been developed using the generalpurpose finite element program. To study the seismic strength and stiffness for recycled aggregate concretefilled steel tube racfst frame, twoframe specimens made up of racfst column and reinforced recycled aggregate concrete rac beam were used for a seismic test under reversed lowcycle loading. It was found that the differences between the element.
In this paper, the permeability properties of fine recycled aggregate concrete are presented. Pdf behaviour of steel tubular stub and slender columns filled with. Using jaw crusher the rc beam were broken into smaller pieces and sieved through 4. Creep and shrinkage in concrete filled steel tubes. Experimental performance of recycled aggregate concretefilled. Concrete recycling gains importance because it protects natural resources and eliminates the need for disposal by using the readily available concrete as an aggregate source for new concrete or pavement subbase layers. It is commonly used as a base layer for other construction materials. Roederc,jimad a key lab of structures dynamic behavior and control of the ministry of education harbin institute of technology, harbin 150090, china bshenzhen graduate school, harbin institute of technology, shenzhen 518055, china. Kang this paper discusses the properties of rca, the effects of rca use on concrete material properties, and the large scale impact of rca on structural members. Compressive and flexural behaviour of recycled aggregate concrete filled steel tubes racfst under shortterm loadings article pdf available in steel and composite structures 63.