Today article is all about Recycled Concrete Aggregate or Concrete With Recycled Aggregate so if are curious about to learn then read the full article
Definition
Recycled Aggregate is a term that refers to crushed concrete or asphalt mortar from construction waste that is reused in other construction activities.
Recycle concrete aggregate
Concrete is the most common material used for construction around the world approximately a million tons of concrete debris is domed as construction waste per year
These demolished construction materials are often dumped on land and are not reused/recycled for any purpose this affects the environment and fertility of the land recycled concrete in the form of aggregate (concrete with recycled aggregate) would lead to environmental and economic benefits
Apart from these recycled aggregate has several benefits since they are durable like natural aggregate versatile can be used for different functions and so on to use recycled concrete as aggregate for concrete contaminants like reinforcing steel foundation materials soil etc. are removed from the concrete debris
It can be done by screening or air separation demolition using electromagnets etc. then the debris is crushed either manually or mechanically in specified size and quality usually around 20 millimetres to 50 millimetres based on various research
It is generally accepted that around 30% of natural crushed coarse aggregate can be replaced with coarse recycled concrete as an aggregate without significantly affecting any of the properties of the concrete however it is advised to perform the various concrete tests by replacing some part of natural aggregate to determine the perfect proportions of concrete
Uses of recycled concrete aggregates
Recycled Concrete as Aggregate has a wide variety of uses in the field of the construction industry the uses are grouped into two categories unprocessed recycled aggregate and processed recycled aggregate
Unprocessed recycled aggregates
Unprocessed recycled aggregates are used for bulk fills riverbank protection base fill for drainage structures aggregate for road construction etc.
Processed recycled aggregates
The processed recycled aggregates are being utilized for various structural works in bridges pavements used as an aggregate in lean concrete bituminous
Concrete used in the construction of shoulders median barriers sidewalks curbs and gutters etc. we shall focus on the influence of recycled aggregate on concrete properties
Recycled Aggregate Characteristics
The influence of recycled aggregate on concrete properties is described below
As the recycled aggregate is manufactured from dumped construction waste the usage of it will have a significant influence on the strength of concrete
Based on various research conducted by the number of researchers today's data is concluded let us discuss the influence on each property of concrete one by one
Strength of Recycled Concrete
Found that 50 to 100% use of recycled aggregate with natural aggregates decreases the compressive strength of concrete by five percent to 25 percent
However, the use of 30% of recycled aggregate with natural aggregates doesn't show the effect on compressive strength but the 7 days strength of recycled aggregate concrete is less than natural aggregate concrete that a strength gain of RAC is less than natural aggregate concrete
In the case of flexural strength of concrete with recycled aggregate has a marginal influence on the flexural strength of concrete the reduction of flexural strength is limited to 10% the same percentage of reduction is found in the case of shear strength of concrete
This is because the recycled aggregate has weaker spots formed while demolishing the concrete
Durability of Recycled Concrete Aggregates
The durability of recycled aggregates in concrete is influenced by various factors such as aggregate replacement ratio, concrete age, water-cement ratio and moisture content
The recycled aggregate has less durable due to the high porosity of the recycled aggregate
The reason for this decrease is due to the lower resistance of concrete to carbonation chloride penetration and reinforcement corrosion
However, usage of supplementary cementing materials like fly ashes, slag, cement, silica fume etc. improves the durability and strength of the concrete
Modulus of Elasticity of Recycled Concrete Aggregates
Modulus of elasticity of recycled aggregate in concrete is found to be significantly reduced when compared to natural aggregate concrete this reduction percentage will be a maximum of 45% for 100 percentage substitution and a 15% reduction for 30 percentage substitution
Shrinkage And Creep of Recycled Aggregates
Shrinkage and creep deformation of recycled concrete aggregate is found to higher than the natural aggregate concrete that is usually 25 to 35 percent higher
However, this behaviour can be controlled by altering the mix design and water-cement ratio.
Workability of concrete to achieve the same walkability in recycled aggregate concrete as in natural aggregate concrete.
Higher water content is required this is due to the higher water absorption capacity of cycled aggregate also due to high water absorption capacity the specific gravity and bulk density of recycled aggregate is relatively low
Recycled aggregate production in the UK
Take a look at some guidelines provided by www.doeni.gov.uk on Recycled aggregate production in the UK and if you want to download this PDF then see below you will get a download button
If you want to download that click on the button and wait for the timer
References
ACI Committee 555, Removal and Reuse of Hardened Concrete, 2001, 26 pages.
FHWA, Transportation Applications of Recycled Concrete Aggregate, Federal Highway Administration, Washington, D.C., September 2004, 47 pages.
FHWA: Recycle Concrete Aggregate
FAQ 1: Use of Recycle concrete aggregate?
Apart from these recycled aggregate has several benefits since they are durable like natural aggregate versatile can be used for different functions and so on to use recycled concrete as aggregate for concrete contaminants like reinforcing steel foundation materials soil etc. are removed from the concrete debris
FAQ 2: what is Recycled Aggregate Characteristics?
Strength of Recycled Concrete Found that 50 to 100% use of recycled aggregate with natural aggregates decreases the compressive strength of concrete by five percent to 25 percent, Durability of Recycled Concrete Aggregates The durability of recycled aggregates in concrete is influenced by various factors such as aggregate replacement ratio, concrete age, water-cement ratio and moisture content, Shrinkage And Creep of Recycled Aggregates Shrinkage and creep deformation of recycled concrete aggregate is found to higher than the natural aggregate concrete that is usually 25 to 35 percent higher
We just moved into a new house recently, and my husband plans to get a new driveway installed using the recycled aggregates from our old one. It certainly helped when you mentioned that the durability of the recycled aggregates will depend on the ratio of water and cement, as well as its aggregate replacement. I’ll keep this in mind while I look for a supplier that can provide us with 3/4″ recycled asphalt to use for our driveway.