Largest concrete tunnel ring made for Seattle’s Alaskan Way Viaduct

The world’s largest concrete tunnel segment ring has been assembled by CBE Group. Nearly 56 feet in diameter, the ring is made from 10 segments that each weigh 17.6 tons. The tunnel ring will be used for Seattle’s Alaskan Way Viaduct Replacement project. CBE Group has assembled the largest tunnel segment ring in the world […]

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Pre-tensioning Systems and Devices

Pre-tensioning Systems and Devices  section covers the following topics. • Introduction • Stages of Pre-tensioning • Advantages of Pre-tensioning • Disadvantages of Pre-tensioning • Devices • Manufacturing of Pre-tensioned Railway Sleepers 1.3.1 Introduction Prestressing systems have developed over the years and various companies have patented their products. Detailed information of the systems is given in […]

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Advantages and Types of Prestressing

Advantages and Types of Prestressing This section covers the following topics. • Definitions • Advantages of Prestressing • Limitations of Prestressing • Types of Prestressing 1.2.1 Definitions The terms commonly used in prestressed concrete are explained. The terms are placed in groups as per usage. Forms of Prestressing Steel Wires  : Prestressing wire is a […]

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Introduction of Prestressed Concrete Structures

1.1 Introduction This section covers the following topics. • Basic Concept • Early Attempts of Prestressing • Brief History • Development of Building Materials 1.1.1 Basic Concept A prestressed concrete structure is different from a conventional reinforced concrete structure due to the application of an initial load on the structure prior to its use. The […]

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Manufacturing of Pre-tensioned Railway Sleepers

Manufacturing of Pre-tensioned Railway Sleepers The following photos show the sequence of manufacturing of pre-tensioned railway sleepers (Courtesy: The Concrete Products and Construction Company, COPCO, Chennai). The steel strands are stretched in a stress bench that can be moved on rollers. The stress bench can hold four moulds in a line. The anchoring device holds […]

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