ACI-3502R-2004.pdf

ACI 350.2R-04 supersedes ACI 350.2R-97 and became effective June 28, 2004. Copyright © 2004, American Concrete Institute. All rights reserved including rights of reproduction and use in any form or by any means, including the making of copies by any photo process, or by electronic or mechanical device, printed, written, or oral, or recording for sound or visual reproduc- tion or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. ACI Committee Reports, Guides, Standard Practices, and Commentaries are intended for guidance in planning, designing, executing, and inspecting construction. This document is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and recommendations and who will accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all responsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom. Reference to this document shall not be made in contract documents. If items found in this document are desired by the Architect/Engineer to be a part of the contract documents, they shall be restated in mandatory language for incorporation by the Architect/Engineer. 350.2R-1 It is the responsibility of the user of this document to establish health and safety practices appropriate to the specific circumstances involved with its use. ACI does not make any representations with regard to health and safety issues and the use of this document. The user must determine the applicability of all regulatory limitations before applying the document and must comply with all applicable laws and regulations, including but not limited to, United States Occupational Safety and Health Administration (OSHA) health and safety standards. Concrete Structures for Containment of Hazardous Materials Reported by ACI Committee 350 ACI 350.2R-04 This report presents recommendations for structural design, materials, and construction of structures commonly used for hazardous materials contain- ment, including reinforced concrete tanks, sumps, and other structures that require dense, impermeable concrete with high resistance to chemical attack. The report discusses and describes design and spacing of joints, propor- tioning of concrete, placement, curing, and protection against chemicals. Information on liners, secondary containment systems, and leak-detection systems is also included. Keywords: construction joint; joint; joint sealant; precast concrete; pre- stress; water-cementitious material ratio; waterstop. CONTENTS Chapter 1General, p. 350.2R-2 1.1Scope 1.2Definitions 1.3Types of materials *Members of ACI 350 Hazardous Materials Subcommittee who prepared this report. Lawrence Valentine served as Chair and Steven R. Close served as Secretary and then took over as chair during the final processing of this revision. Deceased. James P. Archibald*William J. IrwinAndrew R. Philip Jon B. ArdahlKeith W. Jacobson*Narayan M. Prachand John W. Baker*Dov KaminetzkySatish K. Sachdev Walter N. BennettReza M. KianoushWilliam C. Schnobrich Steven R. Close*David G. KittridgeJohn F. Seidensticker Anthony L. FelderDennis C. Kohl*William C. Sherman Carl A. GentryNicholas A. LegatosLawrence J. Valentine* Clifford GordonLawrence G. MrazekMiroslav F. Vejvoda Paul HedliJaveed A. MunshiPaul Zoltanetzky, Jr. Jerry A. HollandJerry Parnes Charles S. Hanskat Chair Lawrence M. Tabat Secretary John A. AubeAshok K. DhingraClifford T. Early, Jr.* William H. BackousRobert E. DoyleWilliam J. Hendrickson Patrick J. CreeganDonald L. DubeDavid A. Klevete David A. Crocker Consulting and associate members who contributed to this report: 350.2R-2 ACI COMMITTEE REPORT Chapter 2Concrete design and proportioning, p. 350.2R-3 2.1General 2.2Design 2.3Concrete cover 2.4Exposure 2.5Concrete mixture proportions 2.6Fiber-reinforced concrete Chapter 3Waterstops, sealants, and joints, p. 350.2R-6 3.1Waterstops 3.2Joint sealants 3.3Joints Chapter 4Construction considerations, p. 350.2R-8 4.1Sump construction techniques 4.2Curing and protection 4.3Inspection Chapter 5Liners and coatings, p. 350.2R-11 5.1Liners 5.2Coatings 5.3Selection considerations for liners and coatings 5.4Inspection and testing of liner and coating installations Chapter 6Secondary containment, p. 350.2R-14 6.1General 6.2Secondary containment system features 6.3Secondary containment materials Chapter 7Leak-detection systems, p. 350.2R-14 7.1General 7.2Drainage media materials 7.3Design and installation of drainage media Chapter 8References, p. 350.2R-16 8.1Referenced standards and reports 8.2Cited references CHAPTER 1GENERAL 1.1Scope This report is intended for use in the structural design and construction of hazardous material containment systems. Hazardous material containment structures require secondary containment and, sometimes, leak-detection systems. Because of the economic and environmental impact of even small amounts of leakage of hazardous materials, both primary and secondary containment systems should be virtually leak free. Therefore, when primary or secondary containment systems involve concrete, special design and construction techniques are required. This report supplements and enhances the requirements of ACI 350, which is intended for structures commonly used in water containment, industrial and domestic water, and wastewater treatment works. ACI 350, however, does not give specific guidance on the design of the double containment systems, leak-detection systems, or the additional recommendations for enhancing liquid- tightness covered in this report. This report does not apply to primary or secondary containment of cryogenic liquids, nonliquid materials, or to systems containing radioactive materials. The use of information in this report does not ensure compliance with applicable regulations. The recommendations in this report were based on the best technical knowledge available at the time they were written; however, they may be supplemented or superseded by applicable local, state, and national regulations. Therefore, it is important to research such regulations (see Section 8.1) thoroughly. Guidelines for containment and leakage-detection systems given in this report involve combinations of materials that may not be readily available in all areas. Therefore, local distributors and contractors should be contacted during the design process to ensure that materials are available. Proper and thorough inspection of construction is essential to ensure a quality final product. The written program for inspection should be detailed and comprehensive, and should be clearly understood by all parties involved. See Section 4.3 for an inspection checklist. (See ACI 311.4R for guidance in inspection programs.) A preconstruction confer- ence to discuss the program in detail is recommended. Personnel should be qualified, experienced, and certified as applicable to their specialty. 1.2Definitions The definitions in Sections 1.2.1 through 1.2.11 have been correlated with the U.S. Environmental Protection Agency (EPA) Resource Conservation and Recovery Act (RCRA) regulations. 1.2.1 Hazardous materialA hazardous material is defined as having one or more of the following characteristics: ignitable (NFPA 49), corrosive, reactive, or toxic. NOTE: EPA-listed wastes are organized into three categories under RCRA: source-specific wastes, generic wastes, and commercial chemical products. Source specific wastes include sludges and wastewaters from treatment and production processes in specific industries such as petroleum refining and wood preserving. The list of generic wastes includes wastes from common manufacturing and industrial processes such as solvents used in degreasing operations. The third list contains specific chemical products such as benzene, creosote, mercury, and various pesticides. 1.2.2 TankA tank is a stationary containment structure with self-supporting, watertight walls constructed of nonearthen material. 1.2.3 Environmental tankAn environmental tank is a tank used to collect, store, or treat hazardous material. An environmental tank usually provides either primary or secondary containment of a hazardous material. 1.2.4 Tank systemA tank system includes its primary and secondary containment systems, leak-detection system, and the ancillary equipment. 1.2.5 Ancillary equipmentAncillary equipment includes piping, fittings, valves, and pumps. 1.2.6 SumpA sump can be any structural reservoir, usually below grade, designed for collection of runoff or accidental spillage of hazardous material. It often includes CONCRETE STRUCTURES FOR CONTAINMENT OF HAZARDOUS MATERIALS 350.2R-3 troughs, trenches, and piping connected to the sump to help collect and transport runoff liquids. Regulations may not distinguish between a sump and an underground tank. 1.2.7 Primary containment systemA primary containment system is the first containment system in contact with the hazardous material. 1.2.8 Secondary containment systemA secondary containment system is a backup system for containment of hazardous materials in case the primary system leaks or fails for any reason. 1.2.9 Spill or system failureA spill or system failure is any uncontrolled release of hazardous material from the primary containment system into the environment or into the secondary containment system. It may also be from the secondary containment system into the environment. 1.2.10 Spill- or leak-detection systemA spill- or leak- detection system detects, monitors, and signals a spill or leakage from the primary containment system. 1.2.11 Membrane slabA membrane slab is a slab-on- ground designed to be liquid-tight and transmit loads directly to the subgrade. 1.3Types of materials This report provides guidance for the design and construction of environmental tanks and sumps of reinforced concrete construction. Tanks may be constructed of prestressed or nonprestressed reinforced concrete, or steel or other materials with concrete foundations, concrete secondary containment systems, or both. Reinforced concrete is the most widely used material for sumps, particularly below grade. Liners for environmental tanks and sumps are made of stain- less or coated steel, fiber-reinforced plastics (FRP), various combinations of esters, epoxy resins, or thermoplastics. This report outlines and discusses options for construction materials and provides recommendations for use, where applicable. CHAPTER 2CONCRETE DESIGN AND PROPORTIONING 2.1General Concrete is particularly suitable for above- and below- grade environmental primary and secondary containment systems. When properly designed and constructed, concrete containment systems are impermeable and highly resistant to failure during fires. See ACI 216R, CRSI (1980), and Zwiers and Morgan (1989) for information on exposure of concrete to elevated temperatures. Concrete is a general-purpose material that is easy to work with and is resistant to a wide range of chemicals. It is used in construction of both primary and secondary containment systems. The addition of pozzolans, latex, and polymer modi- fiers can increase concretes resistance to chemical attack. Measures that should be considered to help prevent cracking or to control the number and width of cracks include: prestressing, details that reduce or prevent restraint of movements due to shrinkage and temperature changes, higher than normal amounts of nonprestressed reinforcement, closer spacing of reinforcement, shrinkage-compensating concrete, concrete mixtures proportioned to reduce shrinkage, and fiber reinforcement. Additionally, some construction techniques, such as casting floors and walls monolithically (Chapter 4), help prevent or reduce cracking by eliminating the restraint of shrinkage and temperature movements of the subsequently placed concrete along the joint with the previously placed concrete. See ACI 224R and ACI 224.3R for additional information on mitigation of cracking in concrete structures. 2.2Design 2.2.1 Design considerationsThe walls, base slabs, and other elements of containment systems should be designed for pressure due to contained material, lateral earth pressure, buoyancy, wind, seismic, and other superimposed loads. ACI 350 provides requirements for the design of both prestressed and nonprestressed tanks and other environ- mental structures. See ASTM C 913 for additional design provisions relating to factory-precast sumps. ACI 372R, AWWA D110, ACI 373R, and AWWA D115 provide additional guidance for the design of prestressed concrete liquid-containment structures. See ACI 223 for infor- mation and guidance on shrinkage-compensating concrete. Roofs should be designed for dead loads, including any superimposed dead loads (insulation, membranes, mechanical equipment, and earth load, if buried) and live loads (snow, pedestrians, and wheel loads, if applicable). A minimum slope of 2% should be included in the design of floors and trench bottoms to prevent ponding and help drainage. Secondary containment systems for flammable and combustible liquids should have a slope that is in accor- dance with NFPA 30, “Flammable and Combustible Liquids Code,” or an applicable fire code. 2.2.2 Wall thickness and reinforcementThe minimum wall thickness and reinforcing steel location in walls should comply with Table 2.1. 2.2.3 FootingsFootings should be cast on top of, or monolithically with, the floor slab to enhance liquid tightness. Table 2.1Wall thickness and reinforcement locations based on concrete placement consideration DescriptionWall height Minimum thickness Reinforcement location Cast-in-place concrete Over 10 ft (3000 mm) 12 in. (300 mm)Both faces 4 to 10 ft (1200 to 3000 mm) 10 in. (250 mm)Both faces Precast concrete Less than 4 ft (1200 mm) 6 in. (150 mm)Center of wall 4 ft (1200 mm) or more 8 in. (200 mm)Center of wall Less than 4 ft (1200 mm) 4 in. (100 mm)Center of wall DescriptionMinimum wall thickness Tendon prestressed concrete tanksSee ACI 350 Wrapped prestressed concrete tanksSee ACI 350 Note: Placement windows (temporary openings in the forms) or tremies are recom- mended to facilitate concrete placement in cast-in-place walls greater than 6 ft (1800 mm) in height. 350.2R-4ACI COMMITTEE REPORT Upturned footings help reduce restraint of shrinkage and its associated cracking. 2.2.4 Slabs-on-ground 2.2.4.1 Membrane slabsACI 350 provides requirements for the minimum shrinkage and temperature reinforcement and, if post-tensioned, the residual prestressing requirements for membrane floor slabs. Prestressed membrane slabs should have a minimum thickness of 5 in. (125 mm). Nonprestressed membrane slabs should have a minimum thickness of 6 in. (150 mm). To enhance liquid-tightness, membrane slabs should be placed without constr