Elements of a Good Concrete Pipe Specification

David JP Matocha Technical Resource Manager

Hanson Pipe & Precast

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A buried pipeline is a Structural System

This structural system must consider both the Properties of the Pipe and the Properties of the Soil…

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“READERS DIGEST Version” Model “Outline” Specification (Handout) based

upon AASHTO Section 27 – Concrete Pipe

• 27.1 – General (Design) • 27.2 – Working Drawings

• 27.3 – Materials• 27.4 – Assembly

• 27.5 – Installation• 27.6 – Inspection• 27.7 – Measurement• 27.8 - Payment

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AASHTO Section 27 – 27.1 General

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Section 12 Bridge design…

• Sets forth all LRFD (Load and Resistance Factor Design) design criteria for RCP Allows Indirect Design and or Direct

Design for RCP Recommend using direct design for

deep fills not listed in ACPA Fill Height Charts

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Indirect Design Calculate LRFD live load, dead load, fluid load Takes soil/installation contribution into

consideration Calculate load on pipe in lbs/ dia (ft) / length(ft) Determines strength class of pipe required

(ASTM C-76) Steel areas and concrete compressive strength

set forth in AASHTO M 170/ASTM C-76

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Tools for Structural Pipe Design

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AASHTO Section 27 – 27.3 MATERIALS

• Pipe Manufacturing Materials• Joint Materials

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27.3 Pipe Manufacturing Material Specifications

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Joint Materials in 27.3

Cement Mortar – soil tight Other Joint Materials (Mastic) – soil or

silt tight (horizontal) leak resistant (vertical)

Flexible watertight (Rubber Gasket) – silt tight or leak resistant

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AASHTO Joint Selection Criteria = performance parameters divided into a hierarchy with 4 main sub-groups:• Special Design (Water Tight)• Leak Resistant

• Silt Tight• Soil Tight

***AASHTO PP 63-09*** Pipe Joint Performance Parameters

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AASHTO Section 27 – 27.5Installation

27.5 Installation – Contents…..• Bedding & Backfill Materials• Compaction Requirements• Type I – Type IV Standard Installations

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$ $$ $$ $

High Quality Fill

High Compaction Levels

Inspection

Lower Pipe Strengths

Type 1 Installation

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Type 1 Installation

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Type 4 Installation

Native Soils

Limited Compaction Required

No Inspection

High Pipe Strengths

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Type 4 Installation

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AASHTO Section 27 – 27.6Field Inspection

27.6 Inspection – Contents…..• Misalignment• Cracks• Spalls & Slabing