1. Recycled Concrete Aggregates
ET 493-Fall 2013
Instructor: Cris koutsougeras
Advisor: Mohamed Zeidan
By: Chase Charrier AND Garrett tregre

2. Introduction Comparing RCA to Typical Aggregate
1. Performance Analysis
2. Cost Analysis
RCA Typical Aggregate

3. Purpose
Research and test the effectiveness of RCA’s use in the construction field
Increase RCA’s use in the construction field
Provided an ECO friendly industry through RCA’s

4. Moisture Content Test
Purpose is to determine the amount of moisture residing inside the aggregates
Moisture Content Test helps to insure an accurate concrete mix and desired characteristics
Oven Temperature: 110 – 115 degrees F
A. Weight of empty Container
B. Weight of Container + Wet Sample
C. Weight of Container + Dry Sample (after fixed reading)
M.C. = (B – C / C – A) * 100%

5. Trial Mixes

6. Slump Test ASTM C143 Standard
Measures the mixtures fresh concrete properties
Consistency & Workability- measure of the ease at which the concrete flows
Also measures the consistency between multiple batches of concrete
Different slumps are required for different applications
The slump test measures concrete’s behavior to the force of gravity
More slump = more water and workability
Smaller slump = drier mix with less workability

7. Slump Test Procedure
Fresh concrete is placed into a metal cone with a diameter of 4” at one end and 8” at the other end being 12” tall
The concrete is placed into the cone in 3 stages and at each stage the concrete is tampered with a 2’ metal rod, 5/8” in diameter
The final stage is to level off the concrete, remove the cone, and measure the slump

8. Slump Test

9. Air Content Test ASTM C231/C231M-10
Determines the amount of air in a fresh concrete mix
Three Methods:
Pressure Method
Volumetric Method
Free Air Method
Pressure applied to fresh sample of concrete to compress air entrained pores
Meter on device measures pressure
Pressure-to-Volume relationship to Boyle’s Law is used to calculate air content

10. Air Content Test

11. Design Mix

12. Design Mix – Testing Results

13. Compression Test ASTM C39 standard
Measures concrete’s ability to withstand compression forces
Strength normally relates the overall quality of the concrete
Concrete is molded into cylinders in which the length is twice the diameter and the diameter is three times the maximum aggregate size
After 28 days are given for proper time to cure, the cylinders are tested
Compression test is performed by applying an axial load to the test cylinder at a constant rate until failure occurs

14. Compression Test

15. Tensile Test ASTM C496 standard
Measures concrete’s ability to resist tensile forces
Tensile strength is much smaller than concrete’s compression strength
Test is performed by placing a concrete cylinder horizontally under a compression machine and applying a force until splitting occurs
Concrete Cylinder- common size 150mm by 300 mm

16. Durability Test ASTM C779 standard for abrasion testing
Measures of concrete’s ability to last over time
We will measure our concrete’s durability through a sandblasting abrasion test
The concrete abrasion test involves spraying our concrete test piece with a sandblaster from a distance of 75 +/- 2.5mm for a length of 1 min.
The volume lost due to abrasion is measured by filling the abrasion cavities with modeling clay

17. Analysis Typical Aggregate vs. RCA Compare performance is cases of:
Strength
Durability
Workability
Perform cost analysis

18. Timeline Researched typical concrete mixtures: Fall 2013
Created concrete design mix: Fall 2013
Ordered materials: Fall 2013
Conduct trial mixtures/Fresh properties testing: Jan – Feb 6, 2014
Strength and Durability Testing: Feb – Mar 2014
Cost and Performance Analysis: April 2014
Final Report Preparation: Apr-May 2014

19. References 1. ASTM Standards: C143, C231/C231M-10; C39; C496; C779
2. “Concrete Air Entrainment Tests.” Durham Geo Slope Indicator. Durham Geo-Enterprises, Inc durhamgeo.com. Web. 4 Dec
3. Gee, King W. “Use of Recycled Concrete Pavement as Aggregate in Hydraulic-Cement Concrete Pavement.” U.S. Department of Federal Transportation. Federal Highway Administration. 3 July Fhwa.dot.gov. Web.
4. MacDonald, Kevin. "Crushed Concrete." Concrete Construction. Haney Wood, 30 July Web Oct
5. "Material Testing." Compression Test on Concrete. Building Research Institute, n.d. Web. 25 Oct
6. “Materials: Recycled Aggregates.” Concrete Technology. Portland Cement Association. Cement.org. Web.

20. Questions
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