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Your Name Date. Reinforced Concrete Pipe Attributes. 2. Our Industry’s Story & Product Attributes. Historical perspective Important product attributes National standards & specifications Resources Our company Our people Our industry association - ACPA.
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Your Name Date Reinforced Concrete Pipe Attributes www.concrete-pipe.org
2 OurIndustry’s Story & Product Attributes • Historical perspective • Important product attributes • National standards & specifications • Resources • Our company • Our people • Our industry association - ACPA www.concrete-pipe.org
Historical Perspective • Proven history = • Continued improvement of product and production methods • Long term knowledge & understanding by all stakeholders • Verifiable durability www.concrete-pipe.org
Continued Improvement • Early to mid XX00’s = demand for more UG Piping to accommodate sewerage and storm water run-off • Oldest recorded RCP installation – xxxx in xxxxxx, NY • Still some RCP installations from late 1800’s in service today! www.concrete-pipe.org
Continued Improvement • Mid 1800’s to Early 1900’s • Prediction of runoff quantities better understood by engineers • XXXX XXXXX university developed methods for estimating XXXXX on pipe and methods to calculate supporting strength provided by XXXXX pipe culverts • Early 1900’s XXXX became a forum for improved quality of piping products • As US transportation needs - demand for RCP grew (50,000 autos in 1905 grew to X million autos in US by 1918) • By 1930 all states using concrete pipe in their roadway systems! In 1930 approx. X million tons of RCP were produced www.concrete-pipe.org
Continued Improvement…Post 1930 • After great depression & WWII 4 million tons of RCP produced in 1950 • Advancement from 1930-1970 • Performance surveys verify durability of RCP • Increased acceptance of RCP by specifiers • Advancements in research & technology • Production techniques & improved finish product quality • 10 million tons RCP produced annually by xxxx www.concrete-pipe.org
Continued Improvement…Post 1970 • 1970’s - XXX enters sanitary market • 1980’s – beginning of industry consolidation • 1980’s – XXXX begins push into storm drain market • 1990’s – RCP industry continues improvement of production methods and production machinery • See concrete pipe handbook to “read more about product & industry history” www.concrete-pipe.org
No better teacher than HISTORY & EXPERIENCE! Over a century of continued improvements in production & QC process provides best RCP ever produced www.concrete-pipe.org
Attributes of Concrete Pipe • Materials and manufacturing methods • Strength • Design & installation flexibility • Hydraulic efficiency • Durability www.concrete-pipe.org
Materials & Manufacturing Methods www.concrete-pipe.org
Materials Used to Make RCP • Portland cement (ASTM C XXX) • XXXXX reinforcement • Aggregates (XXXX & course) • Water • Typically materials combined to produce a mix with a very low xxxxx-cement ratio. Usually considered a “dry-mix” that produces a “x” slump. www.concrete-pipe.org
Basic Production Steps: • Storage of materials • Materials handling • Reinforcement cage production • Cage machines or wire rollers • Batching and mixing concrete • Pipe forming • Pipe forming methods – dry cast or xxxxxxxxx most common • Curing • Steam, water mist common methods used to control xxxx and moisture • Yarding and storage • See a plant tour! www.concrete-pipe.org
Pipe Forming Methods • Wet Cast • Dry Cast www.concrete-pipe.org
Vibratory Sources • Internal Hydraulic • External Pneumatic Electric Hydraulic www.concrete-pipe.org
Dry Cast 84”x 16’ www.concrete-pipe.org
Wire cage production by cage machine www.concrete-pipe.org
Computer controlled batching and manufacturing is common!See for yourself…. www.concrete-pipe.org
Structural Considerations www.concrete-pipe.org
XXXXXXX A Buried Pipe Must Perform Two Critical Functions? Buried Pipe XXXXXXXXX www.concrete-pipe.org
Structure Provided by Pipe Wall • RCP is designed, manufactured, tested, and installed as a rigid structure with a minimal portion of the loads present supported by the surrounding soil. The majority of the load is distributed too and supported by the pipe. • RCP installation structural strength = pipe wall strength + support from bedding • RCP wall can provide 95% of system strength! • Engineer/designer has flexibility to select how much support provided by pipe vs. bedding installation • Structure is tested at plant to confirm required structural strength! www.concrete-pipe.org
Strength Testing • A common method used to determine structural strength is to conduct a three-edge bearing test. • The load per linear foot which a pipe will support under this condition is termed the three-edge bearing strength. • This test is the most severe loading to which any pipe will be subjected. • There is no lateral support for the pipe, as provided under actual buried conditions, and the applied forces in the test are virtually point loads. • Specification reference: ASTM C497M - 96 www.concrete-pipe.org
3EB Test www.concrete-pipe.org
D-Load Supporting strength of a pipe loaded under xxxxxx-xxxx xxxxxxx (xxx) test conditions, expressed in pounds per linear foot per foot of inside diameter or horizontal span when tested according to ASTM Cxxx. D0.01 = load (psf) to produce 0.01” crack, 12” long DULT = load (psf) to cause structural failure www.concrete-pipe.org
ASTM C-76 D0.01 Dult CLASS I 800 1,200 CLASS II 1,000 1,500 CLASS III 1,350 2,000 CLASS IV 2,000 3,000 CLASS V 3,000 3,750 Pipe Classification www.concrete-pipe.org
Example Class IV 60” Pipe D0.01 = 2,000 Dult = 3,000 Load0.01 = 5’ x 2,000 lbs/ft/ft x 8’ = 80,000 lbs. Loadult = 5’ x 3,000 lbs/ft/ft x 8’ = 120,000 lbs. Before the .01 Design Crack www.concrete-pipe.org
Structure Confirmed before Shipment 60” RCP is tested before it leaves the point of manufacture to prove it can carry the load of a loaded Tractor and trailer with no lateral support! www.concrete-pipe.org
Structure Conduit Concrete Pipe www.concrete-pipe.org
Facts of Structural Strength Component • Structural Strength Proven for over Century • No Other Storm Drain Pipe supports xxxx like RCP Pipe Wall does • Engineer has flexibility to depend more on Plant Tested xxx Vs Installation • STUCTURE IS TESTED & CONFIRMED ON FINISHED PRODUCT! www.concrete-pipe.org
Design & Installation www.concrete-pipe.org
Structural Design = Foundation of all Pipe System • Pipe” must be considered as a “bridge” • Determine live and dead loading conditions • How will pipe be installed • Bedding support to be provided • Predict the “Pipe” performance/Select pipe strength class www.concrete-pipe.org
Steps for Indirect Pipe Design (Determining Required Pipe Strength Class) • 1 - Select the method of installation (trench, embankment, etc.) • 2 -xxxxx • 3 - Determine the live load • 4 - Determine the bedding factor (installation type: 1 – 4) • 5 -xxxxxxxx • 6 - Specify the class www.concrete-pipe.org
Installation Methods Positive Projecting Trench Negative Projecting www.concrete-pipe.org
Positive Projecting Embankment Negative Projecting Embankment TRENCH www.concrete-pipe.org
34 Installation Type Makes a Difference! • Xxxxxx Installation helps support load through frictional forces between trench wall and backfill. • Negative projection partial trench wall helps support similar to trench installation. • Positive projection embankment does not provide any resistance to loads • Conservative approach is to use xxxxxxxxx installation for designs www.concrete-pipe.org
Loads on Pipe • Earth • xxxx • Construction • Other www.concrete-pipe.org
Traffic Load R1 Earth Load Final Backfill Haunching Initial Backfill Bedding R2 Foundation Rigid Pipe www.concrete-pipe.org
37 Installation Flexibility w/RCP • Type I – IV SIDD Installations • Well defined structural backfill materials and compaction • Pressure distribution understood and conservative www.concrete-pipe.org
AASHTO- RCP Standard Installation (SIDD) Overfill SW,ML, or CL H Do Do/6 (MIN) Do(MIN) Excavation Line as required Haunch - see table Bedding see table Di Do/3 Middle Bedding loosely placed uncompacted bedding except for Type 4 Outer Bedding Materials and compaction each side, same requirements as haunch. Foundation www.concrete-pipe.org
39 AASHTO Section 27 – Concrete Culverts • 27.5.2.2-1. Structural Backfill • Type 1: Highest quality installation using select granular soils with high compaction requirements for haunching and bedding. • Type 2: Allows silty granular soils with less compaction required for haunching and bedding. • Type 3: Allows use of soils with less stringent compaction requirements for haunching and bedding. • Type 4: Allows use of onsite native material for haunching and bedding with no compaction required. (6” of Bedding is required if rock foundation) • All Backfill Requirements above to xxxxxx xxxx ONLY • Type 1 = Most Supporting structural strength • Type 4 = Requires 95% of structural strength to be provided by Pipe Wall www.concrete-pipe.org
40 Key Components Of Structural Backfill Of RCP • No compaction under invert. • Haunch Support: • compaction of material to spring line only • Assumes voids are present • adding additional safety factors • Rigid pipe does not require compaction of the overfill www.concrete-pipe.org
41 Gravity Pipe Classes www.concrete-pipe.org
42 Steps for Determining the Required Pipe Strength Class • 1 - Select the method of installation (trench, embankment, etc.) • 2 - Determine the earth load • 3 - Determine the live load • 4 - Determine the bedding factor (installation type: 1 – 4) • 5 - Calculate the required D-Load • 6 - Specify the class www.concrete-pipe.org
43 Resources for Finding Required Pipe Strength • Plug & chug - blue book • Fill height tables • Computer software - PipePac 2000 www.concrete-pipe.org
Hydraulics • SEWERS • Initial & Long Term • Full Flow Conditions • CULVERTS • Inlet Control • Outlet Control www.concrete-pipe.org
Concrete Pipe Design Manual • Foreword • Index of Contents • Chapter 1 : Introduction • Chapter 2 : Hydraulics of Sewers • Chapter 3 : Hydraulics of Culverts • Chapter 4 : Loads and Supporting Strengths • Chapter 5 : Supplemental Data • Tables • Figures • Appendix www.concrete-pipe.org
Culvert Control Conditions • Inlet Control • Water can flow through the culvert at a greater rate than water can enter it • Inlet geometry only • Outlet Control • Water can enter the culvert at a greater rate than water can flow through it • Slope, roughness, length, inlet geometry, headwater, tailwater, & diameter www.concrete-pipe.org
Inlet Control (inlet geometry only) Outlet Control(everything else) H Hw Tw D “n” So Inlet Geometry L D = Diameter L = Culvert Length Hw = Headwater depth n = Mannings roughness Tw = Tailwater depth So = Slope Culvert Hydraulic Characteristics www.concrete-pipe.org
Basic’s- Our Hydraulic Advantage • The xxxxxxxx capacity (the amount of water a pipe can convey) of all types of storm sewer pipe depends on how smooth the interior pipe wall is. xxxxxxxx = More Capacity • Smoothness of pipe represented by Manning’s Roughness Coefficient commonly called xxxxxxx’x “x” • Smaller Manning’s “n” = smoother surface = more water through pipe. www.concrete-pipe.org
You must understand Manning’s “n” • Manning’s Equation can be used to determine barrel capacity of any culvert or open channel. Manning’s Equation is: 2/3 1/2 Q = 1.486 X AR S n Q = discharge, cubic feet/sec A = cross-sectional area of pipe in square feet R = hydraulic radius in feet R = A/WP WP = Wetted Perimeter in feet = circumference of pipe in full flow S = slope, or grade in ft/ft n = manning’s n, coefficient of roughness www.concrete-pipe.org
Concrete Pipe Design Manual www.concrete-pipe.org