2010 FDOT Construction Conference 2010 FDOT Construction Conference Concrete Pavement Concrete Pavement Construction – Just the Facts Jamshid Armaghani, Ph.D., P.E. Jamshid Armaghani Ph D P E Florida Concrete and products Association Concrete Pavements of Today Design – ¾ Optimum and structurally sound ¾ Economical Construction – ¾ ¾ ¾ ¾ Almost 100% automation F t d Fast and paved in a single layer di i l l Smooth Quiet Quality – ¾ Innovative testing equipment to assure structural and functional quality functional quality Materials – ¾ Cement ‐ Locally produced ¾ High strength concrete – i h h New construction and Rehab i d h b AASHTO Pavement Design Guide AASHTO Pavement Design Guide • Empirical methodology based on AASHO Road Test in the late 1950’s • Several versions: – 1961, 1972, 1986, 1993 (Empirical) – Many, many limitations M li i i AASHO Road Test (late 1950’s) (AASHO, 1961) Limitations: Huge Traffic Extrapolation Mechanistic Empirical Pavement Design Guide ( (MEPDG) ) State‐Of‐The‐Art Guide based on fundamental pavement engineering pavement engineering principles, climatic conditions, traffic volumes & material characteristics. It has been calibrated using over 250 pavement sites p throughout the country. MEPDG Climate Traffic Structure,Joints, Reinforcement Materials & Construction DG Inputs Axle load (lb) DG Outputs Mechanistic Response Time Damage Accumulation Field Distress Disstress Damage DG Process Damage Distress Prediction & Reliability 8 MEPDG Design Optimization Options MEPDG Design Optimization Options Widened lanes Sh t J i t Short Joint spacing i Larger size dowels Hi h Higher compressive strength i h Advantage of structural value of support layers Bond at Concrete‐asphalt base interface Florida Limestone with low Coefficient of Fl id Li t ith l C ffi i t f Thermal Expansion. % Crackking MEPDG Output Slipform machine (2) Concrete Spreader (1) Curing/tining machine (3) Paving Train Paving Train Alignment Sensor Elevation Sensor Stringline Leica System Equipment Leica System Equipment Computer on Paver Computer on Paver Adjustable Telescopic Frame Spreader arm Tie bars basket Dowel bars basket On‐site Batch Plant Concrete mixes can be designed to allow opening lane to traffic from 6 hrs to 36 hours Maturity Meter Tie bars away from the Joint and ends of dowel bars Nail dowel basket to AC base to AC base Transverse Tiningg Wide tine spacing can be Noisy Narrow tine spacing (1/2”) produces quieter surface Longitudinal Tines Produce q quiet pavement p Grinding Smoothness Testing Smoothness Testing California Profilograph Laser Profiler Narrow Joints produce quiet pavement Uncontrolled crack from delayed joint sawing Narrow vs. Wide Joints Narrow joints produce quieter pavement Joints > ½” Generate Noise Replacement slab Joint too wide. Will cause noise. Must be ≤ ¼ “ Pervious Concrete Edge Drain Filter Fabric Asphalt subbase Graded aggregate gg g drainage mat beneath curb. Asphalt base