CODES

ADOPTS WITH AMENDMENTS:

International Building Code 2015 (IBC 2015)

California Code of Regulations, Title 24

Chapter 16 Structural Design

Chapter 16A Structural Design

Chapter 17 Special Inspections and Tests

Chapter 17A Special Inspections and Tests

Chapter 18 Soils and Foundations

Chapter 18A Soils and Foundations

Chapter 19 Concrete

Chapter 19A Concrete

Chapter 20 Aluminum

Chapter 21 Masonry

Chapter 21A Masonry

Chapter 22 Steel

Chapter 22A Steel

Chapter 23 Wood

Chapter 24 Glass and Glazing

Chapter 25 Gypsum Board, Gypsum Panel Products and Plaster

Chapter 26 Plastic

Chapter 27 Electrical

Chapter 28 Mechanical Systems

Chapter 29 Plumbing Systems

Chapter 30 Elevators and Conveying Systems

Chapter 31 Special Construction

Chapter 31A Systems for Window Cleaning or Exterior Building Maintenance

Chapter 31B [DPH] Public Pools

Chapter 31C [DPH] Radiation

Chapter 31D [DPH] Food Establishments

Chapter 31E Reserved

Chapter 31F [SLC] Marine Oil Terminals

Chapter 32 Encroachments Into the Public Right-Of-Way

Chapter 33 Safeguards During Construction

Chapter 34 Reserved

Chapter 34A Existing Structures

Chapter 35 Referenced Standards

Appendix A Employee Qualifications

Appendix B Board of Appeals

Appendix C Group U—agricultural Buildings

Appendix D Fire Districts

Appendix E Reserved

Appendix F Rodentproofing

Appendix G Flood-Resistant Construction

Appendix H Signs

History Note Appendix

Appendix I Patio Covers

Appendix J Grading

Appendix K Group R-3 and Group R-3.1 Occupancies Protected by the Facilities of the Central Valley Flood Protection Plan

Appendix L Earthquake Recording Instrumentation

Appendix M Tsunami-Generated Flood Hazard

Italics are used for text within Sections 1903A through 1905A of this code to indicate provisions that differ from ACI 318.
State of California amendments in these sections are shown in italics and underlined.

The provisions of this chapter shall govern the materials, quality control, design and construction of concrete used in structures.

The scope of application of Chapter 19A is as follows:

  1. Structures regulated by the Division of the State Architect-Structural Safety (DSA-SS), which include those applications listed in Section 1.9.2.1. These applications include public elementary and secondary schools, community colleges and state-owned or state-leased essential services buildings.
  2. Applications listed in Sections 1.10.1, and 1.10.4, regulated by the Office of Statewide Health Planning and Development (OSHPD). These applications include hospitals, skilled nursing facilities, intermediate care facilities, and correctional treatment centers.

    Exception: [OSHPD 2] Single-story Type V skilled nursing or intermediate care facilities utilizing wood-frame or light-steel-frame construction as defined in Health and Safety Code Section 129725, which shall comply with Chapter 19 and any applicable amendments therein.

DSA-SS and OSHPD adopt this chapter and all amendments.

Exception: Amendments adopted by only one agency appear in this chapter preceded with the appropriate acronym of the adopting agency, as follows:

  1. Division of the State Architect-Structural Safety:

    • [DSA-SS] For applications listed in Section 1.9.2.1
  2. Office of Statewide Health Planning and Development.

    • [OSHPD 1] – For applications listed in Section 1.10.1.
    • [OSHPD 4] – For applications listed in Section 1.10.4.
Structural concrete shall be designed and constructed in accordance with the requirements of this chapter and ACI 318 as amended in Section 1905A of this code. Except for the provisions of Sections 1904A and 1907A, the design and construction of slabs on grade shall not be governed by this chapter unless they transmit vertical loads or lateral forces from other parts of the structure to the soil.
Anchoring to concrete shall be in accordance with ACI 318 as amended in Section 1905A, and applies to cast-in (headed bolts, headed studs and hooked J- or L-bolts), post-installed expansion (torque-controlled and displacement-controlled), undercut and adhesive anchors.
Systems of structural steel acting compositely with reinforced concrete shall be designed in accordance with Section 2206A of this code.

The construction documents for structural concrete construction shall include:

  1. The specified compressive strength of concrete at the stated ages or stages of construction for which each concrete element is designed.
  2. The specified strength or grade of reinforcement.
  3. The size and location of structural elements, reinforcement and anchors.
  4. Provision for dimensional changes resulting from creep, shrinkage and temperature.
  5. The magnitude and location of prestressing forces.
  6. Anchorage length of reinforcement and location and length of lap splices.
  7. Type and location of mechanical and welded splices of reinforcement.
  8. Details and location of contraction or isolation joints specified for plain concrete.
  9. Minimum concrete compressive strength at time of posttensioning.
  10. Stressing sequence for posttensioning tendons.
  11. For structures assigned to Seismic Design Category D, E or F, a statement if slab on grade is designed as a structural diaphragm.
  12. Openings larger than 12 inches (305 mm) in any dimension shall be detailed on the structural drawings.
Special inspections and tests of concrete elements of buildings and structures and concreting operations shall be as required by Chapter 17A and Section 1910A.
The words and terms defined in ACI 318 shall, for the purposes of this chapter and as used elsewhere in this code for concrete construction, have the meanings shown in ACI 318 as modified by Section 1905A.1.

Materials used to produce concrete, concrete itself and testing thereof shall comply with the applicable standards listed in ACI 318.

Exception: The following standards as referenced in Chapter 35 shall be permitted to be used.

  1. ASTM C150
  2. ASTM C595
  3. ASTM C1157

Where required, special inspections and tests shall be in accordance with Chapter 17A and Section 1910A.

Glass fiber-reinforced concrete (GFRC) and the materials used in such concrete shall be in accordance with the PCI MNL 128 standard.

Insulating concrete form material used for forming flat concrete walls shall conform to ASTM E2634. [OSHPD 1 & 4] Not Permitted by OSHPD.

Modify ACI 318 Section 26.4.1.2.1(a).(1) as follows:

(1) Normal weight aggregate: Aggregate shall be non-reactive as determined by one of the methods in ASTM C33 Appendix XI: Methods for Evaluating Potential for Deleterious Expansion Due to Alkali Reactivity of an Aggregate. Aggregates deemed to be deleterious or potentially deleterious may be used with the addition of a material that has been shown to prevent harmful expansion in accordance with Appendix XI of ASTM C33, when approved by the building official.

Modify ACI 318 Section 26.4.2.2(b) and Table 26.4.2.2(b) as follows:

The maximum percentage of pozzolans, including fly ash and silica fume, and slag cement in concrete assigned to all exposure categories shall be in accordance with Table 26.4.2.2(b) and Section 26.4.2.2(b) Items (1) and (2).

Where pozzolans are used as cementitous materials, duration for minimum specified compressive strength of concrete (f’c) that exceeds 28 days shall be considered an alternative system.

Not permitted

Modify ACI 318 Section 26.6.4.1(b) by adding the following:

Shop fusion welded stirrup/tie cage (or spiral assemblies) consisting of low-alloy steel reinforcing stirrups/ties conforming to ASTM A706 and longitudinal holding wires, conforming to ASTM A1064 shall be permitted. The fusion welds shall be made by machines using electric resistance welds. Tack welding of primary reinforcing bars together or to stirrups/ties is not permitted. Fusion welding of holding wires is not permitted on any portion of a reinforcing bar that is or will be bent in accordance with ACI 318 Section 25.3.

Structural concrete shall conform to the durability requirements of ACI 318.

The registered design professional shall assign nonstructural concrete a freeze-thaw exposure class, as defined in ACI 318, based on the anticipated exposure of nonstructural concrete. Nonstructural con crete shall have a minimum specified compressive strength, f'c, of 2,500 psi (17.2 MPa) for Class F0; 3,000 psi (20.7 MPa) for Class F1; and 3,500 psi (24.1 MPa) for Classes F2 and F3. Nonstructural concrete shall be air entrained in accordance with ACI 318.

The text of ACI 318 shall be modified as indicated in Sections 1905A.1.1 through 1905A.1.16.

Modify ACI 318, Section 4.12.2.2 by adding the following:

Where prestressed concrete elements are restrained from movement, an analysis of the stresses in the pre-stressed elements and loads in the adjoining structural system induced by the above-described effects shall be made in accordance with PCI Design Handbook.

Modify ACI 318 Section 4.12.2.3 by adding the following:

For prestressed concrete members with recessed or dapped ends, an analysis of the connections shall be made in accordance with procedures given in PCI Design Handbook.

Modify ACI 318, Section 9.6.1.3 by adding the following:

This section shall not be used for members that resist seismic loads, except that reinforcement provided for foundation elements for one-story wood-frame or one-story light steel buildings need not be more than one-third greater than that required by analysis for all loading conditions.

Replace ACI 318, Section 11.2.4.1 as follows:

11.2.4.1 – Walls shall be anchored to intersecting elements such as floors or roofs; or to columns, pilasters, buttresses, of intersecting walls and footings with reinforcement at least equivalent to No. 4 bars at 12 inches (305 mm) on center for each layer of reinforcement.

Add Section 11.7.6 to ACI 318.1 as follows:

11.7.6 – Reinforcement. Perimeters of precast walls shall be reinforced continuously with a minimum of one No. 5 bar extending the full height and width of the wall panel. Where wall panels do not connect to columns or other wall panels to develop at least 75 percent of the horizontal wall steel as noted below, vertical perimeter bars shall be retained by hooked wall bars

A continuous tie or bond beam shall be provided at the roof line either as a part of the roof structure or part of the wall panels as described in the next paragraph below. This tie may be designed as the edge member of the roof diaphragm but, in any case, shall not be less than equivalent to two No. 6 bars continuous. A continuous tie equivalent to two No. 5 bars minimum shall also be provided either in the footing or with an enlarged section of the floor slab.

Wall panels of shear wall buildings shall be connected to columns or to each other in such a manner as to develop at least 75 percent of the horizontal wall steel. No more than half of this continuous horizontal reinforcing shall be concentrated in bond or tie beams at the top and bottom of the walls and at points of intermediate lateral support. If possible, cast-in-place joints with reinforcing bars extending from the panels into the joint a sufficient distance to meet the splice requirements of ACI 318, Section 25.5.2, for Class A shall be used. The reinforcing bars or welded tie details shall not be spaced over eight times the wall thickness vertically nor fewer than four used in the wall panel height. Where wall panels are designed for their respective overturning forces, the panel connections need not comply with the requirements of this paragraph.

Exception: Nonbearing, nonshear panels such as nonstructural architectural cladding panels or column covers are not required to meet the provisions of this section.

Modify ACI 318 by adding Section 11.9 as follows:

11.9 – Foundation walls. Horizontal reinforcing of concrete foundation walls for wood-frame or light-steel buildings shall consist of the equivalent of not less than one No. 5 bar located at the top and bottom of the wall. Where such walls exceed 3 feet (914 mm) in height, intermediate horizontal reinforcing shall be provided at spacing not to exceed 2 feet (610 mm) on center. Minimum vertical reinforcing shall consist of No. 3 bars at 24 inches (610 mm) on center.

Where concrete foundation walls or curbs extend above the floor line and support wood-frame or light-steel exterior, bearing or shear walls, they shall be doweled to the foundation wall below with a minimum of No. 3 bars at 24 inches (610 mm) on center. Where the height of the wall above the floor line exceeds 18 inches (457 mm), the wall above and below the floor line shall meet the requirements of ACI 318, Section 11.6 and 11.7.

Add Section 12.7.3.4 to ACI 318 as follows:

12.7.3.4 – At least two No. 5 bars in diaphragms having two layers of reinforcement in both directions and one No. 5 bar in diaphragms having a single layer of reinforcement in both directions shall be provided around openings larger than 12 inches in any dimension in addition to the minimum reinforcement required by Section 12.6.

Modify ACI 318, Sections 17.2.3.4.2, 17.2.3.4.3(d) and 17.2.3.5.2, to read as follows:

17.2.3.4.2 – Where the tensile component of the strength-level earthquake force applied to anchors exceeds 20 percent of the total factored anchor tensile force associated with the same load combination, anchors and their attachments shall be designed in accordance with 17.2.3.4.3. The anchor design tensile strength shall be determined in accordance with Section 17.2.3.4.4.

Exception: Anchors designed to resist wall out-of-plane forces with design strengths equal to or greater than the force determined in accordance with ASCE 7, Equation 12.11-1 or 12.14-10, and Section 1604A.8.2 of this code shall be deemed to satisfy Section 17.2.3.4.3(d).

17.2.3.4.3(d) – The anchor or group of anchors shall be designed for the maximum tension obtained from design load combinations that include E, with E increased by Ω0. The anchor design tensile strength shall be calculated from 17.2.3.4.4.

17.2.3.5.2 – Where the shear component of the strength-level earthquake force applied to anchors exceeds 20 percent of the total factored anchor shear force associated with the same load combination, anchors and their attachments shall be designed in accordance with 17.2.3.5.3. The anchor design shear strength for resisting earthquake forces shall be determined in accordance with 17.5.

Exceptions:

  1. For the calculation of the in-plane shear strength of anchor bolts attaching wood sill plates of bearing or nonbearing walls of light-frame wood structures to foundations or foundation stem walls, the in-plane design shear strength in accordance with 17.5.2 and 17.5.3 need not be computed and 17.2.3.5.3 shall be deemed to be satisfied, provided all of the following are met:

    1. 1.1. The allowable in-plane shear strength of the anchor is determined in accordance with AWC NDS Table 11E for lateral design values parallel to grain.
    2. 1.2. The maximum anchor nominal diameter is 5/8 inch (16 mm).
    3. 1.3. Anchor bolts are embedded into concrete a minimum of 7 inches (178 mm).
    4. 1.4. Anchor bolts are located a minimum of 13/4 inches (45 mm) from the edge of the concrete parallel to the length of the wood sill plate.
    5. 1.5. Anchor bolts are located a minimum of 15 anchor diameters from the edge of the concrete perpendicular to the length of the wood sill plate.
    6. 1.6. The sill plate is 2-inch or 3-inch nominal thickness.
  2. For the calculation of the in-plane shear strength of anchor bolts attaching cold-formed steel track of bearing or nonbearing walls of anchor bolts attaching cold-formed steel track of bearing or nonbearing walls of light-frame construction to foundations or foundation stem walls the in-plane design shear strength in accordance with 17.5.2 and 17.5.3 need not be computed and 17.2.3.5.3 shall be deemed to be satisfied, provided all of the following are met:

    1. 2.1. The maximum anchor nominal diameter is 5/8 inch (16 mm).
    2. 2.2. Anchors are embedded into concrete a minimum of 7 inches (178 mm).
    3. 2.3. Anchors are located a minimum of 13/4 inches (45 mm) from the edge of the concrete parallel to the length of the track.
    4. 2.4. Anchors are located a minimum of 15 anchor diameters from the edge of the concrete perpendicular to the length of the track.
    5. 2.5. The track is 33 to 68 mil designation thickness.

    Allowable in-plane shear strength of exempt anchors, parallel to the edge of concrete shall be permitted to be determined in accordance with AISI S100, Section E3.3.1.

  3. In light-frame construction, bearing or non-bearing walls, shear strength of concrete anchors less than or equal to 1 inch (16 mm) in diameter of sill plate or track to foundation or foundation stem wall need not satisfy 17.2.3.5.3 (a) through (c) when the design strength of the anchors is determined in accordance with 17.5.2.1(c).

Modify ACI 318, Table 19.2.1.1 as follows:

For concrete designed and constructed in accordance with this chapter, f ’c, shall not be less than 3,000 psi (20.7 MPa). Reinforced normal weight concrete with specified compressive strength higher than 8,000 psi (55 MPa) shall require prior approval of structural design method and acceptance criteria by the enforcement agency.

Modify ACI 318, Section 18.5, by replacing Section 18.5.2.1, adding new Section 18.5.2.2 and renumbering existing Sections 18.5.2.2 and 18.5.2.3 to become 18.5.2.3 and 18.5.2.4, respectively:

18.5.2.1 – In connections between wall panels, yielding shall be restricted to steel elements or reinforcement. In connections between wall panels and the foundation, they shall be designed per Section 1616A.1.16.

18.5.2.2 – Connections that are designed to yield shall be capable of maintaining 80 percent of their design strength at deformation induced by the design displacement or shall use type 2 mechanical splices.


18.5.2.3 – Elements of the connection that are not designed to yeild shall develop at least 1.5 Sy.

18.5.2.4 – In structures assigned to SDC D, E or F, wall piers shall be designed in accordance with 18.10.8 or 18.14 in ACI 318.

Modify ACI 318, Section 18.10.6.5 by adding the following:

(c) Where boundary members are not required by ACI 318 Section 18.10.6.2 or 18.10.6.3 minimum reinforcement parallel to the edges of all structural walls and the boundaries of all openings shall consist of twice the cross-sectional area of the minimum shear reinforcement required per lineal foot of wall. Horizontal extent of boundary element shall be in accordance with ACI 318 Section 18.10.6.4 (a), (b) and (c).

Add Section 18.12.6.2 to ACI 318 as follows:

18.12.6.2 – Collector and boundary elements in topping slabs placed over precast floor and roof elements shall not be less than 3 inches (76 mm) or 6 db thick, where db is the diameter of the largest reinforcement in the topping slab.

Modify ACI 318, Section 18.13.1.1, to read as follows:

18.13.1.1 – Foundations resisting earthquake-induced forces or transferring earthquake-induced forces between a structure and ground shall comply with the requirements of 18.13 and other applicable provisions of ACI 318 unless modified by Chapter 18A of the California Building Code.

Replace Table 21.2.2 as follows:

TABLE 21.2.2

STRENGTH REDUCTION FACTOR Φ FOR MOMENT, AXIAL FORCE, OR COMBINED MOMENT AND AXIAL FORCE

NET TENSILE STRAIN εtCLASSIFICATIONΦ
Type of transverse reinforcement
Spirals conforming to 25.7.3Other
εt ≤ εtyCompression-controlled0.75(a)0.65(b)
εty < εt < 0.005Transition1,2(c)(d)
εt ≥ 0.005Tension-controlled30.9(e)0.9(f)

1. For sections classified as transition, it shall be permitted to use Φ corresponding to compression-controlled sections.

2. ε t * is the greater of net tensile strain calculated for Pn = 0.1Agf'c and 0.005.

3. For sections with factored axial compression force Pu ≥ 0.1Agf' c, Φ shall be calculated using equation (c) or (d) for sections classified as transition, as applicable.

Add Section 24.2.1.1 to ACI 318 as follows:

24.2.1.1 – Span to depth ratio. Prestressed Beam and Slab Span to depth ratios for continuous prestressed concrete members shall not exceed the following, except when calculations of deflections and vibration effects prove that greater values may be used without adverse effects:

  • Beams ......................................30
  • One-way slabs .........................40
  • Two-way floor slabs ................40
  • Two-way roof slabs .................44

These ratios should be decreased for special conditions such as heavy loads and simple spans.

Maximum deflection criteria shall be in accordance with ACI 318 Section 24.2.2.

Replace ACI 318 Section 26.12.2.1(a) by the following:

26.12.2.1(a) Samples for strength tests of each class of concrete placed each day shall be taken not less than once a day, or not less than once for each 50 cubic yards (345 m3) of concrete, or not less than once for each 2,000 square feet (186 m2) of surface area for slabs or walls. Additional samples for seven-day compressive strength tests shall be taken for each class of concrete at the beginning of the concrete work or whenever the mix or aggregate is changed.

Not permitted by OSHPD and DSA-SS

The thickness of concrete floor slabs supported directly on the ground shall not be less than 31/2 inches (89 mm). A 6-mil (0.006 inch; 0.15 mm) polyethylene vapor retarder with joints lapped not less than 6 inches (152 mm) shall be placed between the base course or subgrade and the concrete floor slab, or other approved equivalent methods or materials shall be used to retard vapor transmission through the floor slab.

Exception: A vapor retarder is not required:

  1. For detached structures accessory to occupancies in Group R-3, such as garages, utility buildings or other unheated facilities.
  2. For unheated storage rooms having an area of less than 70 square feet (6.5 m2) and carports attached to occupancies in Group R-3.
  3. For buildings of other occupancies where migration of moisture through the slab from below will not be detrimental to the intended occupancy of the building.
  4. For driveways, walks, patios and other flatwork that will not be enclosed at a later date.
  5. Where approved based on local site conditions.

Shotcrete is mortar or concrete that is pneumatically projected at high velocity onto a surface. Except as specified in this section, shotcrete shall conform to the requirements of this chapter for reinforced concrete and the provisions of ACI 506. The specified compressive strength of shotcrete shall not be less than 3,000 psi (20.69 MPa).

[DSA-SS] Exception: The reference to ACI 506 shall be to ACI 506.2, unless otherwise approved by the enforcing agent. The specified compressive strength of structural shotcrete shall not be less than 4,000 psi (27.58 MPa) unless specifically approved by the enforcing agent.

Concrete or masonry to receive shotcrete shall have the entire surface thoroughly cleaned and roughened by sand blasting, and just prior to receiving shotcrete, shall be thoroughly cleaned of all debris, dirt and dust. Concrete and masonry shall be wetted before shotcrete is deposited, but not so wet as to overcome suction. Sand for sand blasting shall be clean, sharp and uniform in size, with no particles that will pass a 50-mesh screen. [DSA-SS] Cleaning and roughening provisions of ACI 506.2, Section 2.4.2, may alternatively be permitted.

Shotcrete proportions shall be selected that allow suitable placement procedures using the delivery equipment selected and shall result in finished in-place hardened shotcrete meeting the strength requirements of this code.

Coarse aggregate, if used, shall not exceed 3/4 inch (19.1 mm).

For shear walls, when total rebar in any direction is more than 0.31 in2/ft. or rebar size is larger than # 5, shotcrete shall conform to course aggregate grading No. 2 per Table 1.1 of ACI 506.


[DSA-SS] Exception: The table reference shall be to Table 1908A.3 instead.

TABLE 1908A.3
GRADING LIMITS FOR COMBINED AGGREGATES


SIEVE SIZE,
U.S. STANDARD SQUARE MESH
PERCENT BY WEIGHT PASSING INDIVIDUAL SIEVES
Grading No. 1 Grading No. 2
3/4 in. (19 mm)
1/2 in. (12 mm) 100
3/8 in. (10 mm) 100 90 to 100
No. 4 (4.75 mm) 95 to 100 70 to 85
No. 8 (2.4 mm) 80 to 98 50 to 70
No. 16 (1.2 mm) 50 to 85 35 to 55
No. 30 (600 µm) 25 to 60 20 to 35
No. 50 (300 µm) 10 to 30 8 to 20
No. 100 (150 µm) 2 to 10 2 to 10
Reinforcement used in shotcrete construction shall comply with the provisions of Sections 1908A.4.1 through 1908A.4.4.
The maximum size of reinforcement shall be No. 5 bars unless it is demonstrated by preconstruction tests that adequate encasement of larger bars will be achieved.

When No. 5 or smaller bars are used, there shall be a minimum clearance between parallel reinforcement bars of 21/2 inches (64 mm). When bars larger than No. 5 are permitted, there shall be a minimum clearance between parallel bars equal to six diameters of the bars used. When two curtains of steel are provided, the curtain nearer the nozzle shall have a minimum spacing equal to 12 bar diameters and the remaining curtain shall have a minimum spacing of six bar diameters.

Exception: Subject to the approval of the building official, required clearances shall be reduced where it is demonstrated by preconstruction tests that adequate encasement of the bars used in the design will be achieved.

Lap splices of reinforcing bars shall utilize the noncontact lap splice method with a minimum clearance of 2 inches (51 mm) between bars. The use of contact lap splices necessary for support of the reinforcing is permitted when approved by the building official, based on satisfactory preconstruction tests that show that adequate encasement of the bars will be achieved, and provided that the splice is oriented so that a plane through the center of the spliced bars is perpendicular to the surface of the shotcrete.
Shotcrete shall not be applied to spirally tied columns.
A test panel shall be shot, cured, cored or sawn, examined and tested prior to commencement of the project. The sample panel shall be representative of the project and simulate job conditions as closely as possible. The panel thickness and reinforcing shall reproduce the thickest and most congested area specified in the structural design. It shall be shot at the same angle, using the same nozzleman and with the same concrete mix design that will be used on the project. The equipment used in preconstruction testing shall be the same equipment used in the work requiring such testing, unless substitute equipment is approved by the building official. Reports of preconstruction tests shall be submitted to the building official as specified in Section 1704A.5.
Any rebound or accumulated loose aggregate shall be removed from the surfaces to be covered prior to placing the initial or any succeeding layers of shotcrete. Rebound shall not be used as aggregate.

Except where permitted herein, unfinished work shall not be allowed to stand for more than 30 minutes unless edges are sloped to a thin edge. For structural elements that will be under compression and for construction joints shown on the approved construction documents, square joints are permitted. Before placing additional material adjacent to previously applied work, sloping and square edges shall be cleaned and wetted.

The film of laitance which forms on the surface of the shotcrete shall be removed within approximately two hours after application by brushing with a stiff broom. If this film is not removed within two hours, it shall be removed by thorough wire brushing or sand blasting. Construction joints over eight hours old shall be thoroughly cleaned with air and water prior to receiving shotcrete.

In-place shotcrete that exhibits sags, sloughs, segregation, honeycombing, sand pockets or other obvious defects shall be removed and replaced. Shotcrete above sags and sloughs shall be removed and replaced while still plastic.
During the curing periods specified herein, shotcrete shall be maintained above 40°F (4°C) and in moist condition.

[DSA-SS] Exception: Curing temperatures shall be maintained in accordance with the more restrictive requirements specified in ACI 506.2, Section 3.7.1.2, unless specifically approved by the enforcing agent.
Shotcrete shall be kept continuously moist for 24 hours after shotcreting is complete or shall be sealed with an approved curing compound.
Final curing shall continue for seven days after shotcreting, or for three days if highearly-strength cement is used, or until the specified strength is obtained. Final curing shall consist of the initial curing process or the shotcrete shall be covered with an approved moisture-retaining cover.
Natural curing shall not be used in lieu of that specified in this section unless the relative humidity remains at or above 85 percent, and is authorized by the registered design professional and approved by the building official.
Strength tests for shotcrete shall be made in accordance with ASTM C1604 by an approved agency on specimens that are representative of the work and which have been water soaked for at least 24 hours prior to testing. When the maximum-size aggregate is larger than 3/8 inch (9.5 mm), specimens shall consist of not less than three 3-inch-diameter (76 mm) cores or 3-inch (76 mm) cubes. When the maximum-size aggregate is 3/8 inch (9.5 mm) or smaller, specimens shall consist of not less than 2-inch-diameter (51 mm) cores or 2-inch (51 mm) cubes.
Specimens shall be taken from the in-place work or from test panels, and shall be taken at least once each shift, but not less than one for each 50 cubic yards (38.2 m3) of shotcrete.
When the maximum-size aggregate is larger than 3/8 inch (9.5 mm), the test panels shall have minimum dimensions of 18 inches by 18 inches (457 mm by 457 mm). When the maximum-size aggregate is 3/8 inch (9.5 mm) or smaller, the test panels shall have minimum dimensions of 12 inches by 12 inches (305 mm by 305 mm). Panels shall be shot in the same position as the work, during the course of the work and by the nozzle-men doing the work. The conditions under which the panels are cured shall be the same as the work. Approval from the enforcement agency shall be obtained prior to performing the test panel method.
The average compressive strength of three cores from the in-place work or a single test panel shall equal or exceed 0.85 f 'c with no single core less than 0.75 f 'c. The average compressive strength of three cubes taken from the in-place work or a single test panel shall equal or exceed f 'c with no individual cube less than 0.88 f 'c. To check accuracy, locations represented by erratic core or cube strengths shall be retested.

Forms for shotcrete shall be substantial and rigid. Forms shall be built and placed so as to permit the escape of air and rebound.

Adequate ground wires, which are to be used as screeds, shall be placed to establish the thickness, surface planes and form of the shotcrete work. All surfaces shall be rodded to these wires.

Shotcrete shall be placed in accordance with ACI 506.

The concrete supplier shall furnish to the enforcement agency certification that the cement proposed for use on the project has been manufactured and tested in compliance with the requirements of ASTM C150 for portland cement and ASTM C595 or ASTM C1157 for blended hydraulic cement, whichever is applicable. When a mineral admixture or ground granulated blast-furnace slag is proposed for use, the concrete supplier shall furnish to the enforcement agency certification that they have been manufactured and tested in compliance with ASTM C618 or ASTM C989, whichever is applicable. The concrete producer shall provide copies of the cementitious material supplier's Certificate of Compliance that represents the materials used by date of shipment for concrete. Cementitious materials without Certification of Compliance shall not be used.

Samples shall be taken from bundles as delivered from the mill, with the bundles identified as to heat number and the accompanying mill certificate. One tensile test and one bend test shall be made from a sample from each 10 tons (9080 kg) or fraction thereof of each size of reinforcing steel.

Where positive identification of the heat number cannot be made or where random samples are to be taken, one series of tests shall be made from each 2 1/2 tons (2270 kg) or fraction thereof of each size of reinforcing steel.

Tests of reinforcing bars may be waived by the structural engineer with the approval of the Building Official for one-story buildings or non-building structures provided they are identified in the construction documents and certified mill test reports are provided to the inspector of record for each shipment of such reinforcement.

All wires or bars of each size from each mill heat and all strands from each manufactured reel to be shipped to the site shall be assigned an individual lot number and shall be tagged in such a manner that each lot can be accurately identified at the jobsite. Each lot of tendon and anchorage assemblies and bar couplers to be installed shall be likewise identified.

The following samples of materials and tendons selected by the engineer or the designated testing laboratory from the prestressing steel at the plant or jobsite shall be furnished by the contractor and tested by an approved independent testing agency:

  1. For wire, strand or bars, 7-foot-long (2134 mm) samples shall be taken of the coil of wire or strand reel or rods. A minimum of one random sample per 5,000 pounds (2270 kg) of each heat or lot used on the job shall be selected.
  2. For prefabricated prestressing tendons other than bars, one completely fabricated tendon 10 feet (3048 mm) in length between grips with anchorage assembly at one end shall be furnished for each size and type of tendon and anchorage assembly.

    Variations of the bearing plate size need not be considered.

    The anchorages of unbonded tendons shall develop at least 95 percent of the minimum specified ultimate strength of the pre-stressing steel. The total elongation of the tendon under ultimate load shall not be less than 2 percent measured in a minimum gage length of 10 feet (3048 mm).

    Anchorages of bonded tendons shall develop at least 90 percent of the minimum specified strength of the prestressing steel tested in an unbonded state. All couplings shall develop at least 95 percent of the minimum specified strength of the prestressing steel and shall not reduce the elongation at rupture below the requirements of the tendon itself.

  3. If the prestressing tendon is a bar, one 7-foot (2134 mm) length complete with one end anchorage shall be furnished and, in addition, if couplers are to be used with the bar, two 4-foot (1219 mm) lengths of bar fabricated to fit and equipped with one coupler shall be furnished.
  4. Mill tests of materials used for end anchorages shall be furnished. In addition, at least one Brinnell hardness test shall be made of each thickness of bearing plate.

Cores of the completed composite concrete construction shall be taken to demonstrate the shear strength along the contact surfaces. The cores shall be tested when the cast-in-place concrete is approximately 28 days old and shall be tested by a shear loading parallel to the joint between the precast concrete and the cast-in-place concrete. The minimum unit shear strength of the contact surface area of the core shall not be less than 100 psi (689 kPa).

At least one core shall be taken from each building for each 5,000 square feet (465m2) of area of composite concrete construction and not less than three cores shall be taken from each project. The architect or structural engineer in responsible charge of the project or his or her representative shall designate the location for sampling.

When post-installed anchors are used in lieu of cast-in place bolts, the installation verification test loads, frequency, and acceptance criteria shall be in accordance with this section.

Test loads or torques and acceptance criteria shall be shown on the construction documents.

If any anchor fails testing, all anchors of the same type shall be tested, which are installed by the same trade, not previously tested until twenty (20) consecutive anchors pass, then resume the initial test frequency.

The test procedure shall be as permitted by an approved evaluation report using criteria adopted in this code. All post-installed anchors shall be tension tested.

Exception: [OSHPD 1 & 4] Torque-controlled post-installed anchors shall be permitted to be tested using torque based on an approved test report using criteria adopted in this code.

Exception [DSA-SS]: Torque-controlled post-installed anchors and screw type anchors shall be permitted to be tested using torque based on an approved test report using criteria adopted in this code.

Alternatively, manufacturer's recommendation for testing may be approved by the enforcement agency, based on an approved test report using criteria adopted in this code.

When post-installed anchors are used for sill plate bolting applications, 10 percent of the anchors shall be tested.

When post-installed anchors are used for other structural applications, all such anchors shall be tested.

When post-installed anchors are used for nonstructural components, such as equipment anchorage, 50 percent or alternate bolts in a group, including at least one-half the anchors in each group, shall be tested.

The testing of the post-installed anchors shall be done in the presence of the special inspector and a report of the test results shall be submitted to the enforcement agency.

Exceptions:

  1. Undercut anchors that allow visual confirmation of full set shall not require testing.
  2. Where the factored design tension on anchors is less than 100 lbs and those anchors are clearly noted on the approved construction documents, only 10 percent of those anchors shall be tested.
  3. Where adhesive anchor systems are used to install reinforcing dowel bars in hardened concrete, only 25 percent of the dowels shall be tested if all of the following conditions are met:

    a. The dowels are used exclusively to transmit shear forces across joints between existing and new concrete.

    b. The number of dowels in any one member equals or exceeds 12.

    c. The dowels are uniformly distributed across seismic force resisting members (such as shear walls, collectors and diaphragms).

    Anchors to be tested shall be selected at random by the special inspector/inspector of record (IOR).

  4. Testing of shear dowels across cold joints in slabs on grade, where the slab is not part of the lateral force-resisting system shall not be required.
  5. Testing is not required for power actuated fasteners used to attach tracks of interior non-shear wall partitions for shear only, where there are at least three fasteners per segment of track.

Required test loads shall be determined by one of the following methods:

  1. Twice the maximum allowable tension load or one and a quarter (11/4) times the maximum design strength of anchors as provided in an approved evaluation report using criteria adopted in this code or determined in accordance with Chapter 17 ofACI 318.

    Tension test load need not exceed 80 percent of the nominal yield strength of the anchor element (= 0.8 Ase fya).

  2. The manufacturer's recommended installation torque based on an approved evaluation report using criteria adopted in this code.

Acceptance criteria for post-installed anchors shall be based on an approved evaluation report using criteria adopted in this code. Field tests shall satisfy the following minimum requirements.

  1. Hydraulic ram method:

    Anchors tested with a hydraulic jack or spring loaded apparatus shall maintain the test load for a minimum of 15 seconds and shall exhibit no discernible movement during the tension test, e.g., as evidenced by loosening of the washer under the nut.

    For adhesive anchors, where other than bond is being tested, the testing apparatus support shall not be located within 1.5 times the anchor’s embedment depth to avoid restricting the concrete shear cone type failure mechanism from occurring.

  2. Torque wrench method:

    Torque-controlled post-installed anchors tested with a calibrated torque wrench shall attain the specified torque within 1/2 turn of the nut; or one-quarter (1/4) turn of the nut for a 3/8 inch sleeve anchor only.

    [DSA-SS] Screw-type anchors tested with a calibrated torque wrench shall attain the specified torque within one-quarter (1/4) turn of the screw after initial seating of the screw head.

The structural use of existing concrete with a core strength less than 1,500 psi (10.3MPa) is not permitted in rehabilitation work.

For existing concrete structures, sufficient cores shall be taken at representative locations throughout the structure, as designated by the architect or structural engineer, so that knowledge will be had of the in-place strength of the concrete. At least three cores shall be taken from each building for each 4,000 square feet (372 m2) of floor area, or fraction thereof. Cores shall be at least 4 inches (102 mm) in diameter. Cores as small as 2.75 inches (70 mm) in diameter may be allowed by the enforcement agency when reinforcement is closely spaced and the coarse aggregate does not exceed 3/4 inch (19 mm).

Crack repair of concrete and masonry member by epoxy injection, shall conform to all requirements of ACI 503.7.

Design and construction of externally bonded FRP systems for strengthening concrete structures shall be in accordance with ACI 440.2R.

Exceptions:

  1. Near-Surface Mounted (NSM) FRP bars shall not be permitted.
  2. Strengthening of shear walls and diaphragms (including chords and collectors) shall be considered as an alternative system.

Design capacities, reliability, serviceability of FRP materials shall be permitted to be established in accordance with ICC-ES AC 125. Minimum inspection requirements of FRP composite systems shall be in accordance with ICC-ES AC 178.

Resources