Description
This report outlines the causes, control, maintenance, and repair of erosion in hydraulic structures. Such erosion occurs from three major causes: cavitation, abrasion, and chemical attack. Design parameters, materials selection and quality, environmental factors, and other issues affecting the performance of concrete are discussed.
Evidence exists to suggest that, given the operating characteristics and conditions to which a hydraulic structure will be subjected, the concrete can be designed to mitigate future erosion. However, when operational factors change or are not clearly known and erosion of concrete surfaces occurs, repairs should follow. This report addresses the subject of concrete erosion, inspection techniques, and repair strategies, providing references to a more detailed treatment of the subject.
Keywords: abrasion; aeration; cavitation; chemical attack; concrete dams; corrosion; erosion; hydraulic structures; spillways.
Table of Contents
CHAPTER 1—INTRODUCTION AND SCOPE
1.1—Introduction
1.2—Scope
CHAPTER 2—NOTATION
2.1—Notation
CHAPTER 3—EROSION BY CAVITATION
3.1—Mechanism of cavitation
3.2—Cavitation index
3.3—Cavitation damage
CHAPTER 4—EROSION BY ABRASION
4.1—General
4.2—Stilling basin damage
4.3—Power plant tailrace damage
4.4—Navigation lock damage
4.5—Tunnel lining damage
4.6—Hydraulic jacking
CHAPTER 5—EROSION BY CHEMICAL ATTACK
5.1—Sources of external chemical attack
5.2—Erosion by mineral-free water
5.3—Erosion by miscellaneous causes
CHAPTER 6—CONTROL OF CAVITATION EROSION
6.1—Hydraulic design principles
Example 1
6.2—Cavitation indexes for damage and construction tolerances
Example 2
6.3—Using aeration to control damage
6.4—Materials
6.5—Materials testing
6.6—Construction practices
CHAPTER 7—CONTROL OF ABRASION EROSION
7.1—Hydraulic considerations
7.2—Materials evaluation
7.3—Materials
CHAPTER 8—CONTROL OF EROSION BY CHEMICAL ATTACK
8.1—Control of erosion by mineral-free water
8.2—Control of erosion from acid attack due to bacterial action
8.3—Control of erosion by miscellaneous chemical causes
CHAPTER 9—PERIODIC INSPECTIONS AND CORRECTIVE ACTION
9.1—General
9.2—Inspection program
9.3—Inspection procedures
9.4—Reporting and evaluation
CHAPTER 10—REPAIR METHODS AND MATERIALS
10.1—Design considerations
10.2—Methods and materials
CHAPTER 11—REFERENCES
Authored documents