ACI-350.1-350.1R-2001.pdf

*Members of ACI 350 Tightness Testing Subcommittee who prepared the report. Past chairmen of ACI 350 who served during a portion of the time required to create this document. Past secretary of ACI 350 who served during a portion of the time required to create this document. Charles S. Hanskat Chairman Roger H. Wood* Subcommittee Chairman Lawrence M. Tabat Secretary James P. Archibald*A. Ray FranksonDov KaminetzkyAndrew R. M. Philip Jon B. Ardahl*Anand B. GogateM. Reza KianoushDavid M. Rogowsky Walter N. BennettWilliam J. HendricksonDavid G. Kittridge*Satish K. Sachdev Steven R. CloseJerry A. HollandNicholas A. LegatosWilliam C. Schnobrich Ashok K. Dhingra*William IrwinLarry G. MrazekSudhaker P. Verma Anthony L. FelderJerry Parnes Voting Subcommittee Members Osama Abdel-AaiClifford T. EarlyJack MollJohn F. Seidensticker John BakerClifford GordonCarl H. MoonWilliam C. Sherman Patrick J. CreeganPaul HedliJaveed A. MunshiLauren A. Sustic* David A. CrockerKeith W. JacobsonTerry PatziasLawrence J. Valentine Ernst T. CviklDennis C. KohlNarayan M. PrachandMiroslav Vejvoda Robert E. DoyleBryant MatherPaul Zoltanetzky Tightness Testing of Environmental Engineering Concrete Structures (ACI 350.1-01) and Commentary (350.1R-01) REPORTED BY ACI COMMITTEE 350 ACI Committee 350 Environmental Engineering Concrete Structures This standard gives methods and criteria for tightness testing of environmental engineering concrete structures. It is applicable to liquid and gas containment structures constructed with concrete or a combination of concrete and other materials. It includes hydrostatic, surcharged hydrostatic, and pneumatic tests. The standard is written in explicit, mandatory language, and as such, is intended for reference in project specifications. The values stated in inch-pounds are to be regarded as the standard. The values given in parentheses are for information only. The text of this standard is accompanied by a commentary which provides explanatory material. The commentary shall not be considered as requirements of the standard. This standard may involve hazardous materials, operations, and equipment. This standard does not purport to address all of the safety problems associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use. Keywords: hydrostatic; leakage; pneumatic; reservoirs; tanks (containers); tests; tightness; tightness criteria. ACI Committee Reports, Guides, Standard Practices, and Commentaries are intended for guidance in planning, designing, executing, and inspecting construction. This Commentary is intended for the use of individuals who are competent to evaluate the significance and limitations of its content and rec- ommendations and who will accept responsibility for the application of the material it contains. The American Concrete Institute disclaims any and all re- sponsibility for the stated principles. The Institute shall not be liable for any loss or damage arising therefrom. Reference to this commentary shall not be made in contract documents. If items found in this Commentary 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. ACI 350.1-01/350.1R-01 became effective on December 11, 2001. Copyright 2001, 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 any electronic or mechanical device, printed or written or oral, or recording for sound or visual reproduction or for use in any knowledge or retrieval system or device, unless permission in writing is obtained from the copyright proprietors. 350.1/350.1R-2ACI STANDARD/COMMENTARY CONTENTS CHAPTER 1TIGHTNESS TESTING OF TANKS .350.1/350.1R-3 1.0Notations 1.1Scope 1.2General CHAPTER 2HYDROSTATIC TEST, HST, FOR OPEN OR COVERED TANKS 350.1/350.1R-7 2.1Standard test 2.2Tank inspection and HST-VIO, part 1 2.3Tank preparation and HST-VIO, part 2 2.4Test Measurements 2.5Quantitative criteria CHAPTER 3SURCHARGED HYDROSTATIC TEST, SHT, FOR CLOSED TANKS.350.1/350.1R-11 3.1Standard test 3.2Tank inspection 3.3Test preparation and SHT-VIO 3.4Test measurements 3.5Quantitative criteria CHAPTER 4PNEUMATIC TEST, PNT, FOR CLOSED TANKS350.1/350.1R-15 4.1Standard test 4.2Tank inspection 4.3Test preparation 4.4Test measurements 4.5Quantitative criteria CHAPTER 5COMBINATION HYDROSTATIC-PNEUMATIC TEST, CPT, FOR CLOSED TANKS350.1/350.1R-19 5.1Standard test 5.2Tank Inspection 5.3Test Preparation 5.4Test measurements 5.5Quantitative criteria CHAPTER 6REFERENCES .350.1/350.1R-23 TIGHTNESS TESTING OF ENVIRONMENTAL CONCRETE STRUCTURES350.1/350.1R-3 STANDARDCOMMENTARY 1.0Notations F = Fahrenheit Temperature (C= Centigrade Temperature) PG= Design gas pressure, psig (kPa gage) PV= Vacuum pressure for which the tank has been designed, psig (kPa gage) R1.1Scope The American Concrete Institute Committee 350, Envi- ronmental Engineering Concrete Structures, recognized the need for standardized procedures of testing of reinforced concrete structures for water tightness. A joint committee of ACI 350 and American Water Works Association Commit- tee 400, Waterproofing, prepared the ACI 350.1R/AWWA 400 Report1 on recommendations for water tightness of reinforced concrete containment structures. This Standard is an evolution of that report. The pneumatic tests in this Standard are based on the Amer- ican Petroleum Institutes publication API 620 for Large, Welded, Low-Pressure Storage Tanks.2 Under most circumstances, only one type of test would be used for a tank. The type of test selected should best repre- sent the design loading condition of the tank. If the tank is designed for several different types of loading conditions, tests should be selected to represent each of the types. The tank should have the maximum amount of the exterior surface visible during the test. New partially buried or bur- ied tanks should not have the backfill placed against the walls and roof prior to testing. If the structure is not designed to be test loaded prior to backfill placement, the test should only be performed with the backfill in place. CHAPTER 1 TIGHTNESS TESTING OF TANKS 1.1Scope 1.1.1This Standard is for the tightness testing of concrete environmental engineering liquid and gas- eous containment tanks. The included tests are: (a) Hydrostatic Test for Open or Covered Tanks, HST. See Chapter 2; (b) Surcharged Hydrostatic Test for Closed Tanks, SHT. See Chapter 3; (c) Pneumatic Test for Closed Tanks, PNT. See Chapter 4; and (d) Combination Hydrostatic-Pneumatic Test for Closed Tanks, CPT. See Chapter 5. 1.1.2The tightness testing procedures and requirements contained herein are applicable to reser- voirs, basins, and tanks constructed of concrete or a combination of concrete and other materials. The owner shall be permitted to waive certain preparatory items but the waiver of such items shall not change the test criteria. R1.1.2Tightness testing of concrete tanks for the con- tainment of liquids and low-pressure gases may be neces- sary to verify that the structure can fulfill its intended purpose. Tanks for environmental facilities often include structures designed with a combination of concrete and other materials. These include concrete digesters with float- ing steel covers; tanks with aluminum dome roofs; basins with metal, wood or plastic covers; process basins with steel walls and concrete floors; and similar structures. The com- bination of materials in the tank construction should not preclude performing the tightness testing of the tank nor the tightness testing of the joint between the different materials. 350.1/350.1R-4ACI STANDARD/COMMENTARY STANDARDCOMMENTARY R1.1.3Multi-cell tanks for water and wastewater facili- ties are not always designed for water tightness between adjacent cells. During maintenance, it is considered accept- able for these tanks to have some seepage into an empty cell from an adjacent full cell. It is not practical to establish a water loss criterion for testing cells where seepage is accept- able. Therefore, these multi-cell tanks should be tested as a unit. The design of multi-cell tanks should be reviewed to determine that they are multi-cell tanks rather than a single tank with non-structural baffle walls. 1.1.3Each cell of multi-cell tanks shall be consid- ered a single tank and tested individually unless other- wise directed by the engineer. 1.1.4The HST procedures and requirements herein are also applicable for tightness testing of open concrete liquid transmission structures such as cast- in-place concrete channels and conduits. 1.1.6These provisions are not intended for pre- cast concrete structures such as culverts and pipes, for hazardous material primary containment struc- tures, for cryogenic storage structures, or for high- pressure gas tanks. 1.2General 1.2.1Definitions. The following definitions shall apply to words and phrases used in this Standard. 1.2.1.1TankA concrete basin, reservoir, chan- nel, or conduit to be tested regardless of whether it has a closed or open top or is constructed partially or entirely of concrete. 1.2.1.2Open tank A tank where the top sur- face of the tanks contents is exposed to the atmo- sphere. 1.2.1.3Covered tankA tank where the con- tents are protected from exterior contamination by the presence of a cover or roof over the top of the tank. 1.2.1.4Closed tankA tank where the roof or cover is used to prevent the escape of the contents, including gases emanating from the contents, to the outside atmosphere. 1.2.1.5Soap sudsWater impregnated with soap or synthetic detergent used to indicate air pas- sage through joints or defects by the formation of soap bubbles. R1.2General 1.1.5The HST procedures and requirements, where applicable, can be used for tightness testing of concrete paved structures, such as channels and impoundments. R1.1.4Tightness testing of liquid transmission struc- tures will require the use of major, very tight, temporary bulkheadsa feature usually not defined in the structure design. R1.1.5Concrete paving is placed, finished, and jointed in a different manner than are cast-in-place concrete tanks. The differences in design, details, and construction will affect the tightness of the structure and some test procedures may not be applicable. R1.1.6Precast concrete structures and structures for the primary containment of hazardous materials, cryogenic fluids, or high-pressure gases require specialized testing methods, procedures, and criteria. TIGHTNESS TESTING OF ENVIRONMENTAL CONCRETE STRUCTURES350.1/350.1R-5 STANDARDCOMMENTARY 1.2.1.6FittingsA material or product, other than concrete, embedded in the concrete or passing through the concrete. 1.2.1.7Low-pressureA pressure less than 2.5 psig (17 kPa gage). 1.2.1.8Vacuum boxA box with a transparent top, open bottom, and air sealing bottom edges used in conjunction with an air pump capable of creating at least a 3 psi (20 kPa) vacuum within the box. 1.2.2The structural adequacy of the tank shall be verified for the test pressure or pressures to be applied. One type of test shall not be substituted for another type of test without approval of the engineer. 1.2.3Unless specifically allowed by the engi- neer, the tank shall not be tested before all of the structure is complete and the tanks concrete has attained its specified compressive strength. R1.2.2When using the stated procedures and criteria for an existing tank, it should not be assumed that the tank has been designed for the test pressure or for the specific type of test. A tank designed for a triangular hydrostatic pressure may not be able to withstand a uniform pneumatic pressure with the same maximum intensity. R1.2.3Pressure testing of a partially completed tank may not be a true test of tightness of the tank. Shrinkage cracks may continue to propagate during the construction period after the test. The fastening of walkways, exterior stairways, roof beams, or other structural elements above or outside of the tanks liquid containment shell, after the tight- ness test, may provide additional shell restraint and result in the formation of concrete cracks. 350.1-350.1R-6ACI STANDARD/COMMENTARY Notes TIGHTNESS TESTING OF ENVIRONMENTAL CONCRETE STRUCTURES350.1/350.1R-7 STANDARDCOMMENTARY 2.1Standard Test 2.1.1The standard hydrostatic test shall have the prefix HST followed by the test criterion expressed as the maximum allowable percent loss per day of the test water volume. Standard criteria for the HST test are: R2.1Standard Test R2.1.1The test designation system adopted allows for future revision, if necessary, to the tightness criteria. The sys- tem makes the tightness criterion used for the test self-evident. Different materials, methods of construction, and design philosophy may result in different tank tightness. A pre- stressed concrete tank with the concrete always in compres- sion may have a different tightness than a reinforced concrete tank with the concrete partially in tension. A lined tank will have a different tightness than an unlined tank. Based on reasonable tightness of different types of tank con- struction, six standard criteria have been established. The selected criterion should consider the tank design, tank con- struction, and the tightness necessary for the stored contents. R2.1.2The visual test, as a preliminary procedure for all tests in this Standard, should minimize the number of tank retests. R2.1.3Liners should be considered when HST-NML tightness criterion is required. The tightness criterion should consider that tanks without expansion joints normally have a smaller floor area than tanks with expansion joints. Liquid loss through floor imperfections will be at a higher rate than through wall imperfections due to the higher hydrostatic pressure at the floor level. Expansion joints also can leak due to the detail work required in constructing the joint. Movement at expansion joints during the life of the struc- ture may result in future leakage. R2.2Tank inspection and HST-VIO, Part 1 R2.2.1The requirement to clean the tank surfaces is to allow cracks and defects to be observed and not obscured by mud, material spills, or stains. Sprayed water may be necessary to wash foreign material from the concrete surfaces. Mud, soil, or other foreign material on the tank floor may not only obscure the floor condition but may temporarily fill defects, voids, or cracks, thus giving test results that may not reflect the true condition of the tank. The same inspection procedure is required for the concrete that is to be covered by a liner as for concrete that will be exposed. Liners are generally used to ob