Composites, particularly fiber-reinforced polymer materials, are increasingly being adopted or considered as alternatives to conventional materials for civil infrastructure applications, such as bridges, buildings, waterfront structures, waste treatment facilities, and facilities for transmission and transport of utilities. This article provides information on seismic retrofit applications and discusses the repair and strengthening of components, such as beams, slabs, large-diameter pipes, and bridge decks.

This article provides a summary of the concepts discussed in the articles under the Section “Product Reliability, Maintainability, and Repair” in ASM Handbook, Volume 21: Composites. The Section covers a range of topics that include the general issues for reliability, maintenance, and repair of composite structures. Specific structural applications, including marine, infrastructure, and aircraft related issues, are discussed. Operators of equipment employing composite structures in primary load applications must understand the issues with respect to maintenance and repair action. The Section also provides information on these requirements.

This article provides a summary of the concepts discussed in the articles under the Section “Introduction to Testing and Certification” in ASM Handbook, Volume 21: Composites. The Section covers the basics of what to test, how to test, and how many to test to obtain specific properties of common advanced composite materials.

Polyurethane is any polymer consisting of a chain of repeating organic units joined by urethane linkages. Polyurethane polymers are formed through step-growth polymerization by making a monomer containing at least two isocyanate functional groups to react with another monomer containing at least two hydroxyl (alcohol) groups. This article provides a detailed account of the protective coatings used in the building, infrastructure, and architectural markets. It focuses on the various types of polyurethane coatings used in these applications: moisture-cure and two-pack aromatic coatings as primers and topcoats, moisture-cure aromatic elastomeric high-build coatings, moisture-cure aliphatic topcoats, two-pack aliphatic polyurethane coatings as topcoats, and one- and two-pack polyurethane dispersion coatings as sealers and topcoats. It also includes a section on the health effects of isocyanates.

Construction-scale additive manufacturing, also known as construction three-dimensional printing (C3DP), has received significant attention as a technology that could transform the construction industry by offering a highly automated construction process for various applications. This article presents an overview of the current developments in C3DP as well as future prospects and discusses the technical and regulatory barriers to its widespread adoption by the construction industry. It also presents a detailed discussion on construction-scale additive manufacturing technologies.

This article provides the framework for the investigation of bridge failures. It explains the types of bridge loading and presents the regulatory provisions for bridges. Some bridge failures in the U.S. that resulted in significant changes in bridge manufacturing, design, regulation, and/or maintenance are also discussed. In addition, the article provides information on traffic damage and fatigue cracking that result in bridge failures. The need for steels with better fracture toughness in bridge design is also discussed.

This article begins with a brief history of composite materials and discusses its characteristics. It presents an introduction to the constituents, product forms, and fabrication processes of composite materials. The article concludes with a discussion on the applications of organic-matrix, metal-matrix, and ceramic-matrix composites.

Electromagnetic signals at microwave and millimeter-wave frequencies are well suited for inspecting dielectric materials and composite structures in many critical applications. This article presents a partial list of reported nondestructive testing (NDT) application areas for microwaves. It discusses the advantages and limitations of inspection with microwaves. The article discusses the physical principles, including reflection and refraction, absorption and dispersion, scattering, and standing waves. It provides a discussion on terahertz (THz) imaging for nondestructive evaluation (NDE). The article concludes with information on ground-penetration radar (GPR) that uses electromagnetic radiation and detects the reflected signals from subsurface structures.

The earliest commercial use of carbon fibers is often attributed to Thomas Edison's carbonization of cotton and bamboo fibers for incandescent lamp filaments. This article describes the manufacture of PAN-based carbon fibers and pitch-based carbon fibers. It discusses the properties and characteristics of carbon fibers in terms of axial structure, transverse structure, and interfacial bonding. The article discusses the typical applications of carbon fibers, including aerospace and sporting goods. It concludes with a discussion on anticipated developments in carbon fibers.

This article provides an overview of cost analysis in materials selection. It discusses the several categories of alternatives for cost analysis. These include rules of thumb, accounting methods, and analytical methods. The article describes the methods for evaluating materials alternatives on the basis of both direct economic costs and indirect social costs. It considers the life cycle costs of alternative body-in-white designs and life cycle analysis. The various elements of cost are introduced with a case study concerned with the manufacture, use, and disposal of the automobile body-in-white.

Both nondestructive testing (NDT) and nondestructive evaluation (NDE) use noninvasive measurement techniques to gain information about defects and various properties of materials, components, and structures. This article begins with a discussion on the historical development of quantitative measurement techniques, evaluation reliability, and quantitative interpretation of nondestructive inspection methods. The common nondestructive evaluation methods, along with their uses and limitations, are summarized in a table. The article conceptually illustrates the interplay of NDE and fracture mechanics in the damage tolerant approach. It concludes with information on pressure vessel applications that can be separated into three protocols used by military nuclear power, commercial nuclear power, and non-nuclear pressure vessels and/or fired boilers.

This article describes selected U.S. environmental statutes and regulations that are pertinent to material surface finishers. It provides information on the applicability, requirements, and permitting conditions of the Clean Air Act, the Resources Conservation and Recovery Act, the Superfund Amendments and Reauthorization Act, and the Clean Water Act.

This article provides an overview of thermal spray processes. It describes the microstructural character of thermal spray coatings as well as the criteria for coating selection. The optimization, parameterization, and surface preparation and treatments for the thermal spray coatings are also discussed. The article illustrates the adhesion of polymer coatings and the thermal spray process used to remove lead-base paint. It provides information on the specifications, standardization, and guidelines for thermal spray applicators.

Bridges and highways are core components of transportation system and range from pavements with earth, gravel, or stone covered by a thin bituminous surface course to a continually reinforced Portland cement concrete (PCC) roadway with or without a bituminous wear course. This article provides information on bridges and dowels and the reinforcement used in PCC roadways that suffer from corrosion. An overview is provided on the rise in awareness of the corrosion issues affecting bridges and highways. The chemistry and structure of concrete and its role as an electrolyte in promoting corrosion are also discussed. The article addresses reinforcement, including conventional, prestressed, cable stays, and corrosion-resistant reinforcement. It deals with the electrochemical methods for the inspection and corrosion control of embedded reinforcement. The article also reviews the corrosion of metal bridges and corrosion control, including the use of weathering steels and coating systems.

This article analyzes the estimates of the cost of corrosion, made in various countries at various times. The data are extrapolated to a 2004 base and then projected to the global economy. The chronological order of the countries are the United States of America, the United Kingdom, Australia, Japan, Canada, Germany, Poland, South Africa, Czechoslovakia, Belgium, Netherlands, Sweden, Finland, the Union of Soviet Socialist Republics, Kuwait, India, and the Basque Region.

This article provides an overview of the finite-element-based analyses (FEA) of advanced composite structures and highlights key aspects such as the homogenization of materials properties and post-processing of numerical results. It discusses the analysis of composite structures based on micromechanics and macromechanics. The article describes the FEA of 3-D solid elements, 2-D cylindrical shell elements, and 1-D beam elements. It contains a table that lists the commercially available finite element codes related to the analysis of fibrous composite materials. The article presents classical examples of the mechanics of composite materials to illustrate the aspects of multilayered composite structures.

Weathering steels contain deliberate additions of alloying elements intended to increase the atmospheric corrosion resistance of steel. This article provides an overview of atmospheric corrosion testing. It describes the estimation of the atmospheric corrosion behavior of weathering steels by two methods such as short-term exposure tests and calculation of a corrosion index based on the steel composition. The article highlights some generalities about corrosion mechanisms. Based on the mechanism of atmospheric corrosion resistance of weathering steel, working rules for creating the protective oxide film have evolved. The article also provides case histories that illustrate both the violations of these rules and suggestions on how to avoid certain maintenance problems that may be encountered with weathering steels.

Coating of cast irons is done to improve appearance and resistance to degradation due to corrosion, erosion, and wear. This article describes inorganic coating methods commonly applied to cast irons. The coating methods include plating, hot dip coating, conversion coating, diffusion coating, cladding, porcelain enameling, and thermal spray. Organic coatings have a wide variety of properties, but their primary use is for corrosion resistance combined with a pleasing colored appearance. The article discusses the various types of organic coatings applied to cast irons. Practically any degree of smoothness or roughness and requirement for color and gloss can be filled by organic coatings. The article describes abrasive blast cleaning, abrasive waterjet cleaning and finishing, vibratory finishing, barrel finishing, and shot peening for processing iron castings.

Compression molding is the single largest primary manufacturing process used for automotive composite applications. This article provides an overview of the compression molding process. It describes the basic design, materials, and processing equipment of three main groups of composite materials, namely, glass-fiber-mat-reinforced thermoplastics, long-fiber-reinforced thermoplastics, and sheet molding compounds. The article also presents information on the application examples and market volume of compression molding.

This article describes the synthesis, manufacturing, and properties of both the neat soy-based resins and the glass, flax, and hemp composites. A tabulation of the fatty-acid distribution in various plant oils is provided. The article discusses synthetic pathways for triglyceride-based monomers and provides a discussion on acrylated epoxidized soybean oils (AESO), maleinized soyoil monoglyceride (SOMG/MA), and maleinized hydroxylated oil (HO/MA). The polymer properties of the AESO, SOMG/MA, and HO/MA are also discussed. The article explains the ballistic impact resistance of soy resin composites and concludes with a discussion on biodegradable composites.