CHAPTER 19 CONCRETE - ecodes.biz

1 CHAPTER 19 CONCRETESECTION provisions of this CHAPTER shall govern thematerials, quality control, design and construction of concreteused in Plain and reinforced concreteshall be designed and constructed in accordance with therequirements of this CHAPTER and ACI 318 as amended in Sec-tion 1908 of this code. Except for the provisions of Sections1904 and 1910, the design and construction of slabs on gradeshall not be governed by this CHAPTER unless they transmit verti-cal loads or lateral forces from other parts of the structure to Source and format and subject mat-ter of Sections 1902 through 1907 of this CHAPTER are patternedafter, and in general conformity with, the provisions for struc-tural CONCRETE in ACI Construction docu-mentsfor structural CONCRETE construction shall include:1.

2 The specified compressive strength of CONCRETE at thestated ages or stages of construction for which eachconcrete element is The specified strength or grade of The size and location of structural elements, reinforce-ment and Provision for dimensional changes resulting fromcreep, shrinkage and The magnitude and location of prestressing Anchorage length of reinforcement and location andlength of lap Type and location of mechanical and welded splices Details and location of contraction or isolation jointsspecified for plain Minimum CONCRETE compressive strength at time Stressing sequence for posttensioning For structures assigned toSeismic Design CategoryD,E or F, a statement if slab on grade is designed as astructural diaphragm (see Section of ACI318).

3 Special inspectionof concreteelements of buildings and structures and concreting operationsshall be as required by CHAPTER words and terms defined in ACI 318shall, for the purposes of this CHAPTER and as used elsewhere inthis code for CONCRETE construction, have the meanings shownin ACI 318 as modified by Section 1903 SPECIFICATIONS FOR TESTS AND used to produce CONCRETE , concreteitself and testing thereof shall comply with the applicable stan-dards listed in ACI required, special inspectionsand tests shall be in accordance with CHAPTER Glass fiber reinforced fiber rein-forced CONCRETE (GFRC) and the materials used in such con-crete shall be in accordance with the PCI MNL 128 1904 DURABILITY Water-cementitious materials maximumwater-cementitious materials ratios are specified in ACI 318,they shall be calculated in accordance with ACI 318, Section Exposure categories and shall beassigned to exposure classes in accordance with ACI 318, Sec-tion , based on:1.

4 Exposure to freezing and thawing in a moist condition ordeicer chemicals;2. Exposure to sulfates in water or soil;3. Exposure to water where the CONCRETE is intended to havelow permeability; and4. Exposure to chlorides from deicing chemicals, salt,saltwater, brackish water, seawater or spray from thesesources, where the CONCRETE has steel CONCRETE mixtures shall conformto the most restrictive maximum water-cementitious materialsratios and minimum specified CONCRETE compressive strengthrequirements of ACI 318, Section , based on the exposureclasses assigned in Section :For occupancies and appurtenances thereto inGroup R occupancies that are in buildings less than fourstories above grade plane, normal-weight aggregate con-crete is permitted to comply with the requirements of based on the weathering classification (freezing andthawing) determined from Figure in lieu of therequirements of ACI 318, Table OREGON STRUCTURAL SPECIALTY CODE459 Italics are used for text within Sections 1903 through 1908 of this code to indicate provisions that differ from ACI :\data\CODES\STATE CODES\Oregon\2010\Structural Specialty_Building\Final VP\ , February 10, 2010 8:24:27 AMColor profile.

5 Generic CMYK printer profileComposite Default screen4602010 OREGON STRUCTURAL SPECIALTY CODECONCRETETABLE SPECIFIED COMPRESSIVE STRENGTH (fc)TYPE OR LOCATION OF CONCRETE CONSTRUCTIONMINIMUM SPECIFIED COMPRESSIVE STRENGTH (fcat 28 days, psi)Negligible exposureModerate exposureSevere exposureBasement wallscand foundations not exposed to the weather2,5002,5002,500aBasement slabs and interior slabs on grade, except garage floorslabs2,5002,5002,500aBasement wallsc, foundation walls, exterior walls and othervertical CONCRETE surfaces exposed to the weather2,5003,000b3,000bDriveways, curbs, walks, patios, porches, carport slabs, steps andother flatwork exposed to the weather, and garage floor slabs2,5003,000b, d3,500b, dFor SI: 1 pound per square inch = CONCRETE in these locations that can be subjected to freezing and thawing during construction shall be of air-entrained CONCRETE in accordance with CONCRETE shall be air entrained in accordance with Section Structural plain CONCRETE basement walls are exempt from the requirements for exposure conditions of Section (see Section ).

6 D. For garage floor slabs where a steel trowel finish is used, the total air content required by Section is permitted to be reduced to not less than 3 percent, pro-vided the minimum specified compressive strength of the CONCRETE is increased to 4,000 PROBABILITY MAP FOR CONCRETEa, b, ca. Lines defining areas are approximate only. Local areas can be more or less severe than indicated by the region A severe classification is where weather conditions encourage or require the use of deicing chemicals or where there is potential for a continuous presence ofmoisture during frequent cycles of freezing and thawing. A moderate classification is where weather conditions occasionally expose CONCRETE in the presence ofmoisture to freezing and thawing, but where deicing chemicals are not generally used.

7 A negligible classification is where weather conditions rarely expose con-crete in the presence of moisture to freezing and Alaska and Hawaii are classified as severe and negligible, :\data\CODES\STATE CODES\Oregon\2010\Structural Specialty_Building\Final VP\ , February 10, 2010 8:24:28 AMColor profile: Generic CMYK printer profileComposite Default Freezing and thawing that willbe exposed to freezing and thawing, in the presence of mois-ture, with or without deicing chemicals being present, shallcomply with Sections and Air exposed to freezingand thawing while moist shall be air entrained in accordancewith ACI 318, Section Deicing CONCRETE exposed to freez-ing and thawing in the presence of moisture and deicingchemicals, the maximum weight of fly ash, other pozzolans,silica fume or slag that is included in the CONCRETE shall notexceed the percentages of the total weight of cementitiousmaterials permitted by ACI 318, Section Alternative cementitious materials for sulfate expo-sure.

8 Alternative combinations of cementitious materials foruse in sulfate-resistant CONCRETE to those listed in ACI 318,Table shall be permitted in accordance with ACI 318,Section 1905 CONCRETE QUALITY, MIXING AND required strength and durability of con-crete shall be determined by compliance with the proportion-ing, testing, mixing and placing provisions of through shall be proportioned to pro-vide an average compressive strength as prescribed in Sec-tion and shall satisfy the durability criteria ofSection 1904. CONCRETE shall be produced to minimize thefrequency of strengths belowfcas prescribed in CONCRETE designed and constructed in accor-dance with this CHAPTER , fcshall not be less than 2,500 psi( MPa).

9 No maximum specified compressive strengthshall apply unless restricted by a specific provision of thiscode or ACI Selection of CONCRETE propor-tions shall be determined in accordance with the provisions ofACI 318, Section Proportioning on the basis of field experienceand/or trial proportioning determined onthe basis of field experience and/or trial mixtures shall be donein accordance with ACI 318, Section Proportioning without field experience or trial proportioning determined without field expe-rience or trial mixtures shall be done in accordance with ACI318, Section Average strength data become avail-able during construction, it is permissible to reduce the amountby which the average compressive strength (fc) is required toexceed the specified value offcin accordance with ACI 318,Section Evaluation and acceptance of criteriafor evaluation and acceptance of CONCRETE shall be as specifiedin Sections through Qualified shall be tested inaccordance with the requirements in Sections Qualified field testing technicians shallperform tests on fresh CONCRETE at the job site, prepare speci-mens required for curing under field conditions, preparespecimens required for testing in the laboratory and recordthe temperature of the fresh CONCRETE when preparing speci-mens for strength tests.

10 Qualified laboratory techniciansshall perform all required laboratory Frequency of frequency of conduct-ing strength tests of CONCRETE and the minimum number oftests shall be as specified in ACI 318, Section :When the total volume of a given class ofconcrete is less than 50 cubic yards (38 m3), strength testsare not required when evidence of satisfactory strength issubmitted to and approved by the building Strength test prepared foracceptance testing of CONCRETE in accordance with and strength test acceptance criteria shall complywith the provisions of ACI 318, Section Field-cured required by thebuilding official to determine adequacy of curing and pro-tection of CONCRETE in the structure, specimens shall be pre-pared, cured, tested and test results evaluated for acceptancein accordance with ACI 318, Section Low-strength test any strengthtest (see ACI 318, Section )