Lab Prep Materials Mixing Bituminous Mixture Preparation and Testing Sample Prep CE 331 Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 1 of 24
Materials • Bitumen Materials – Naturally occurring Mixing – Organic byproduct Sample Prep – Hydrocarbons Mixture Designs • Asphalt cement Strength Testing – Distillation of Analysis petroleum Example? – Graded by viscosity Report – Many different types CE 331, Printed SP14 Asphalt Preparation and Testing Slide 2 of 24
Types of Asphalt Cement • HMA Materials – 200 to 300 F Mixing – Summer paving season Sample Prep • WMA Mixture Designs – Lower temps (30 to 120 F Strength Testing lower) through chemistry Analysis additions Example? – Reduce costs Report – Better Compaction fhwa.gov – Patches asphaltpavement.org CE 331, Printed SP14 Asphalt Preparation and Testing Slide 3 of 24
Types of Asphalt Cement • Emulsion Materials – asphalt, water, soap Mixing – Colloidal mill Sample Prep – Brown is good Mixture Designs – Hardening (drying) romaco-us.com Strength Testing process is referred to Analysis as “breaking” Example? – Room temperature Report – Typically only 2/3 asphalt!! Pavementinteractive.org CE 331, Printed SP14 Asphalt Preparation and Testing Slide 4 of 24
Asphalt Concrete • Asphalt concrete Materials – Aggregate + binder Mixing • Strength/stability Sample Prep – aggregate (type Mixture Designs and gradation) Strength Testing – asphalt (type and Analysis content) Example? – state of Report compaction Pavementinteractive.org CE 331, Printed SP14 Asphalt Preparation and Testing Slide 5 of 24
Asphalt Concrete - Types Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report Pavementinteractive.org CE 331, Printed SP14 Asphalt Preparation and Testing Slide 6 of 24
Asphalt Concrete - Types • Surface Mixture Materials – Topmost 1” – 2” Mixing – Provide smooth, stable top layer Sample Prep – Low permeability, noise Which Mixture Designs • Binder Mixture Strength Testing mixture do – Next 2” – 4” Analysis – Not as stable or dense you think is Example? – Spread mechanical loads more Report – Coarser gradation expensive? Pavementinteractive.org CE 331, Printed SP14 Asphalt Preparation and Testing Slide 7 of 24
Aggregates Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report Courtesy Dr. Seidel Pavementinteractive.org Penn State Harrisburg CE 331, Printed SP14 Asphalt Preparation and Testing Slide 8 of 24
Setup Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 9 of 24
Mixing • Weigh 3 sizes of aggregate Materials • Mix the coarse aggregate Mixing and ½ of the sand Sample Prep • Add the emulsion and mix Mixture Designs • Add the rest of the sand Strength Testing and mix for at least 5 Analysis minutes Example? • Make sure the aggregates Report are as well coated as possible CE 331, Printed SP14 Asphalt Preparation and Testing Slide 10 of 24
Filling the Molds • Cylindrical Molds: Materials – Ø = 2.5”, h = 3.0” Mixing – spray interior of mold with silicone spray Sample Prep – Wax paper on pedestal and Mixture Designs spray it with silicone Strength Testing – Place the cylinder on Analysis compaction pedestal and Example? carefully spoon mixture into Report the mold until it is full CE 331, Printed SP14 Asphalt Preparation and Testing Slide 11 of 24
Compacting the Samples- • 4 lb., 18” fall Materials • Spray bottom of compacting hammer with silicone. Wax Mixing paper always between Sample Prep pedestal/sample Mixture Designs • Put on your gloves! Strength Testing • Drop the weight 30 times, Analysis adding more material. Invert Example? and repeat Report • Total compactive effort of 120 drops CE 331, Printed SP14 Asphalt Preparation and Testing Slide 12 of 24
Mixture Proportions SURFACE MIX Emulsion Sample 1/2" - 3/8" (g) 3/8" - 1/4" (g) Sand (g) Mold's label Weight (g) Materials 1 40 138 290 29 2 40 138 290 33 Mixing 3 40 138 290 37 4 40 138 290 41 Sample Prep 5 40 138 290 45 Mixture Designs Strength Testing BINDER MIX Emulsion Sample 1/2" - 3/8" (g) 3/8" - 1/4" (g) Sand (g) Mold's label Analysis Weight (g) 1 57 204 213 26 Example? 2 57 204 213 30 Report 3 57 204 213 33.5 4 57 204 213 37.5 5 57 204 213 42 CE 331, Printed SP14 Asphalt Preparation and Testing Slide 13 of 24
Next week…. Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 14 of 24
Strength Testing • Unconfined Materials compression Mixing • Constant deformation Sample Prep rate 0.1 in / min Mixture Designs • Peak load for each Strength Testing specimen Analysis • Check blackboard for Example? the data Report • Srew-type mechanical machine CE 331, Printed SP14 Asphalt Preparation and Testing Slide 15 of 24
Specimen inspection • Uniform loading Materials – Defects Mixing – Loose materials Sample Prep – Unparallel ends Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 16 of 24
Data Analysis • m asphalt = 2 3 ∙ m emulsion Materials m asphalt • AC = total mass : Asphalt Content Mixing Sample Prep • Plot strength vs AC Mixture Designs • Fit a 2 nd order polynomial Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 17 of 24
Data Analysis Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 18 of 24
Optimum Asphalt Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report Optimum asphalt content corresponds to highest strength CE 331, Printed SP14 Asphalt Preparation and Testing Slide 19 of 24
Example if you want… Materials Mixing Sample Prep Mixture Designs Strength Testing Analysis Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 20 of 24
Report • Last Lab Report!!! (w00t) Materials – Let’s make it fast, but go out with bang! Mixing • Executive Summary / Plots and Table / Sample Prep Data in Appendix Mixture Designs • Rubric on bb Strength Testing • Possible questions to answer in Analysis summary are provided on next slide Example? Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 21 of 24
Report • Comment on the mixing effort and appearance of the mixture with various asphalt contents Materials • Comment on the effect of asphalt content on Mixing compaction Sample Prep • From a strength standpoint, what is the optimum asphalt content of each mixture? Mixture Designs • What other aspect of the mixture might cause you to Strength Testing select an asphalt binder that does not give you the Analysis maximum strength? • Why is the surface mix stronger at optimum asphalt Example? content, than the binder mix? Report • Why does the surface mix have a greater optimum asphalt content? CE 331, Printed SP14 Asphalt Preparation and Testing Slide 22 of 24
Report • Plots Materials – Strength vs asphalt content for binder and surface Mixing Sample Prep • Summary Table Mixture Designs – Here are the column headings Strength Testing Max. Analysis Emulsion Asphalt Max Total Sample Comp. Weight (g) Content Load Mass Strength # Example? (lb) (g) (%) (psi) Report CE 331, Printed SP14 Asphalt Preparation and Testing Slide 23 of 24
Questions? Materials Mixing A farmer buys a talking sheepdog and sends him out onto the farm. Sample Prep The dog gets all the sheep into the pen, and then goes back to the farmer. Mixture Designs Strength Testing "There you go boss", he says. "All forty sheep are safely in the pen." Analysis "Forty?", says the farmer. "I only have thirty-six sheep .“ Example? Report "Yeah, I know", says the dog. "But you asked me to round them up." CE 331, Printed SP14 Asphalt Preparation and Testing Slide 24 of 24
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