Concrete Structures

Protection, Repair and Rehabilitation

R. Dodge Woodson

• Publisher: Butterworth-Heinemann
• Year: 2009
• Print ISBN:
  9781856175494
• eBook ISBN:
  9780080949819
• Topic: Technology & Engineering
• Subtopic: Civil Engineering
• Index: Technology & Engineering

The success of a repair or rehabilitation project depends on the specific plans designed for it. Concrete Structures: Protection, Repair and Rehabilitation provides guidance on evaluating the condition of the concrete in a structure, relating the condition of the concrete to the underlying cause or causes of that condition, selecting an appropriate repair material and method for any deficiency found, and using the selected materials and methods to repair or rehabilitate the structure. Guidance is also provided for engineers focused on maintaining concrete and preparing concrete investigation reports for repair and rehabilitation projects. Considerations for certain specialized types of rehabilitation projects are also given. In addition, the author translates cryptic codes, theories, specifications and details into easy to understand language. Tip boxes are used to highlight key elements of the text as well as code considerations based on the International Code Council or International Building Codes. The book contains various worked out examples and equations. Case Studies will be included along with diagrams and schematics to provide visuals to the book. - Deals primarily with evaluation and repair of concrete structures - Provides the reader with a Step by Step method for evaluation and repair of Structures - Covers all types of Concrete structures ranging from bridges to sidewalks - Handy tables outlining the properties of certain types of concrete and their uses

Chapter 1. Understanding concrete

Time takes its toll on concrete structure, which creates a problem for the use of concrete in a country’s infrastructure. Knowing the right principles and procedures for the repair and rehabilitation of concrete structures is a critical element to financial success. Tearing down existing structures and rebuilding them from the ground up can be cost prohibitive. Learning and perfecting the ways to make the most of existing infrastructures are key elements when it comes to sustainable living and safe living conditions.

Many people look at concrete and see nothing but, well, concrete. But the knowledgeable mind sees much more. Are there stress cracks in the surface? Were expansion joints installed properly? Does the color of the concrete indicate a proper curing time? Is the surface a slick, glasslike finish or a brushed finish? Is the material flaking away? Can existing flaws be repaired in such a way to guarantee structural integrity?

Most people take concrete for granted. Yet, it is one of the strongest building blocks of many bridges, highways, and other significant infrastructure. Working with a new installation of concrete is very different from repairing and rehabilitating existing concrete structures. Both types of work have their rules of thumb and their engineering elements. It often requires more experience to repair concrete than it does to install it as new construction. This is what you will learn here.

Are you capable of doing a site inspection and evaluation of existing concrete structures? If not, would you like to be? This is your chance to learn a great deal about existing concrete structures. A few experts may be needed for complicated compromises in concrete construction, but many situations can be assessed personally.

How much do you know about your options when it comes to fixing problems with concrete? Would you like to know more? Of course you would! And this book tells you what to use, when to use it, and how to use it.

What is the best way to avoid the need for concrete repairs? Maintenance is a great place to start, and this procedure will be discussed in detail. If you are looking for specifics on concrete work and codes, you have come to the right place.

So what are you going to learn? Well, here are just a few topics:

Determining the quality of concrete

High-performance concrete

In-place strength of concrete

Pervious concrete used for sustainable building projects

Recycling concrete

Durability testing

Performance specifications and data

Lithium technology

The effects of fly ash

Admixtures

Certifications

Quality control

Control charting

LEED-accredited concrete procedures

Using recycled water in ready-mixed concrete

Predictive testing

Measured compressive strength

Aggregates

Green concrete

Self-sealing concrete

Thermal characteristics

High-belite cement dam concrete

Crack resistance

Mechanical behavior

Secular distortion performance

Corrosion inhibitors

Posttension concrete

Prestressed concrete

Reinforcing steel in concrete structures

Okay, now you know what this book covers, so let’s do it.

Chapter 2. Evaluating concrete in concrete structures

Proper evaluation of concrete requires several steps. The requirements for repairs or rehabilitation are generally established in one of three ways. In the worst case, there is a failure of structural integrity that prompts the need for an evaluation. Visual inspections often reveal a need for further evaluation and testing. If cracks, flaking, or other visual defects are encountered, a full investigation and evaluation are usually warranted. The third way to establish the need for an evaluation is periodic testing. This is the safest way to check the strength and dependability of concrete structures.

Reviewing the Records

Construction documents are typically filed before the permits for construction are issued. In the case of concrete construction, reviewing original documents and a paper trail over the history of the structure is one step in a thorough evaluation. Here are some examples of existing records that should be available for consideration:

■ Design documents

■ Plans

■ Specifications

■ History reports

■ Inspection reports

■ Site inspection results

■ Laboratory test records

■ Concrete records on the materials used in construction and the batch plant

■ Instrumentation documents

■ Operation reports

■ Maintenance reports

■ Monument survey data

Site Survey

A site survey consists of a visual exam of all exposed concrete. The inspectors are looking for any implication of distress that may require repair or rehabilitation. The standard procedure is to create a map of potential defects that are encountered. These could include cracks, disintegration, spalling, or joint deterioration. The mapping process is typically done with foldout sketches of the monolith surfaces. Mapping must include inspection and delineating of pipe and electrical galleries, filling, and emptying, culverts when possible. Core drilling is a common procedure when evaluating concrete. The material recovered from the drilling can be taken to a laboratory for scientific testing.

It is not acceptable to use tests for splitting tensile strength to establish the acceptance of concrete in the field.

Shoddy Workmanship

Shoddy workmanship can lead to significant problems in concrete structures. Site inspections can bring such problems to light and result in further testing. Some of the normal defects that are ...

Table of contents

• Cover Image
• Table of Contents
• Copyright
• Dedication
• Acknowledgments
• About the author
• Introduction
• Chapter 1. Understanding concrete
• Chapter 2. Evaluating concrete in concrete structures
• Chapter 3. Causes of distress and deterioration of concrete
• Chapter 4. Planning and design of concrete repair
• Chapter 5. Concrete removal and preparation for repair
• Chapter 6. Materials and methods for repair and rehabilitation
• Chapter 7. Maintenance of concrete
• Chapter 8. Specialized repairs
• Chapter 9. Troubleshooting defects in concrete
• Chapter 10. Worksite safety
• Chapter 11. First aid
• Chapter 12. Working with the concrete code
• Chapter 13. Test your code knowledge
• Chapter 14. Construction code highlights
• Appendix A. Construction detail samples
• Appendix B. Case study of highway pavement testing
• Appendix C. Helpful calculation methods
• Appendix 4. Other useful information
• Glossary
• Index