1 29 cfr 1926 subpart q concrete and masonry construction

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29 CFR 1926 SUBPART Q

CONCRETE AND MASONRY CONSTRUCTION

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51 killed 170 feet above ground Entire form peeled away from newly

placed concrete

Cooling TowerSt. Mary’s West Virginia 1978

3What the St. Mary’s West Virginia tower would have

looked like if it had been completed.

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Jump forms atop the St. Mary’s structure tore loose, pulling work platforms and concrete down inside the tower.

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Wreckage 168 feet below the top of the St. Mary’s tower being picked apart by investigators looking for clues. The state of West Virginia objected to the site

being cleaned before it could make its own full investigation.

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Part 1926 Subpart QConcrete and Masonry Construction

1926.700 - Scope, application, and definitions applicable to this subpart.

1926.701 - General requirements

1926.702 - Requirements for equipment and tools.

1926.703 - Requirements for cast-in-place Concrete.

1926.703 App - General Requirements for Formwork

1926.704 - Requirements for precast concrete.

1926.705 - Requirements for lift-slab operations.

1926.705 App - Lift Slab Operations

1926.706 - Requirements for masonry construction.

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"Bull float" "Formwork" "Lift slab" "Limited access

zone" "Precast concrete"

"Reshoring" "Shore" "Vertical slip

forms" “Jacking

operation”

29 CFR 1926 700 Scope, application, and definitions

applicable to this subpart.

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(a) Construction loads.

(b) Reinforcing steel.

(c) Post-tensioning operations.

(d) Riding concrete buckets.

(e) Working under loads.

(f) Personal protective equipment.

29 CFR 1926.701General requirements

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1926.701(b) All protruding reinforcing steel, onto and into which employees could fall,shall be guarded to eliminate the hazard of impalement.

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Rebar protection

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1926.701(c) - Post-tensioning operations No employee (except those essential to the post-tensioning operations) shall be permitted to be behind the jack during tensioning operations

12Jack

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Cutting bars

141926.701(d) Riding concrete buckets No employee shall be permitted to ride concrete buckets.

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(a) Bulk cement storage.

(b) Concrete mixers.

(c) Power concrete trowels.

(d) Concrete buggies.

(e) Concrete pumping systems.

(f) Concrete buckets.

(g) Tremies. (h) Bull floats. (i) Masonry saws. (j) Lockout/Tagout

procedures.

702 Equipment and Tools.

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1926.702 (b) Concrete mixers with one cubic yard or larger loading shall be equipped with:• A mechanical device to clear the skip of materials • Guardrails installed on each side of the skip

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1926.702(e)(1) Concrete pumping systems shall be provided with pipe supports designed for 100 percent overload.

(2) Air hoses shall be provided with positive fail-safe joint connectors.

Pumping System

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1926.702(g) Tremies. Sections of tremies and similar concrete conveyances shall be secured with wire rope (or equivalent materials) in addition to the regular couplings or connections.

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Concrete piping systemconnection point

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1926.702 (f) Concrete buckets(1) Concrete buckets equipped with pneumatic gates shall have positive safety latches or similar safety devices installed to prevent premature or accidental dumping.

(2) Concrete buckets shall be designed to prevent concrete from hanging up on top and the sides.

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1926.702 Power-concrete trowels Shall be equipped with a control switch that will automatically shut off the power whenever the hands of the operator are removed from the equipment handle.

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1926.702(d) Concrete buggy handles shall not extend beyond the wheels on either side of the buggy

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1926.702(i) (1)Masonry saws shall be guarded with a semicircular enclosure over the blade

(2)A method of retaining blade fragments shall be incorporated in the design of the semicircular enclosure.

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1926.702(h) Bull floats - Electrocution - Handles

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(a) General requirements for formwork.

(b) Shoring and reshoring.

(c) Vertical slip forms.

(d) Reinforcing steel.

(e) Removal of formwork.

29 CFR 1926.703 Cast-in-place Concrete.

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Form work operations fall protection

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Cast in-place concrete work

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Form work

Form work

Form work

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1926.703 Shoring & re-shoring•Inspected prior to erection•Damaged equipment shall not be used•Inspected immediately prior to, during, and immediately after concrete placement.

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1926.703 (b) Shoring & re-shoring

•Equipment found to be damaged or weakened, shall be immediately reinforced.•Sills shall be sound, rigid, and capable of carrying maximum intended load.

1926.703(b)(6) All base plates, shore heads, extension devices, and adjustment screws shall be in firm contact, and secured when necessary, with the foundation and form.

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1926.703(b)(8)Single post shores

•Design prepared by qualified designer

•Vertically aligned

•Spliced to prevent movement

•Braced in two mutually perpendicular directions at splice level

•Each tier diagonally braced in the same two directions

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Ellis shoringsystem

1926.703(c) Vertical slip forms

Jack rod

Jack

Yoke assembly

Working deck

Wales

Bracing for Wales

Slight batter of sheathingSheathing

Splash board

Thin pipe aroundjack rod

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Vertical slip-form operation

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1926.703(d)Vertical slip form Steel rods or pipes on which jacks climb shall be designed for that purpose and adequately braced when not encased in concrete.

Designed to prevent excessive distortion during jacking

Provided with scaffolds or work platform whereemployees required to pass

Jacks and lifting devicesprovided with mechanical dogs or other automatic holding devices

Form structure maintained within all design tolerances - for plumpness during jacking operations

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1926.703 (e) Removal of formwork

Shall not be removed until employer determines concrete has gained sufficient strength to support its weight and super imposed loads:

Plans and specifications which stipulate conditions for removal of forms and shores; Concrete had been properly tested.

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Flying forms

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(a) Adequate support of wall units, structural framing, and tilt-up panels

(b) Capability of inserts

(c) Imbedded inserts (d) Lifting hardware

(e) No employee under pre-cast concrete members being lifted or tilted into position except those employees required for the erection of those members

1926.704 Pre-cast Concrete.

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Pre-cast concrete operation

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Un pre-stressed slab

Prestressed slab - unloaded

Prestressed slab - loaded

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29 CFR 1926.705 lift-slab operations.

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(a) Lift-slab operations shall be designed and planned by a registered professional engineer

(b) Jacks/lifting units shall be marked

(c) Jacks/lifting units shall not be loaded beyond their rated capacity

(d) Jacking equipment shall not be overloaded

(e) Design and installation of jack lifting units

29 CFR 1926.705 lift-slab operations.

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(f) Jacks/lifting units shall have a safety device installed

(g) Jacking operations shall be synchronized

(h) Automatic controlled leveling

(i) Manually controlled leveling

(j) Maximum number of manually controlled jacks/lifting units

(k) Number of employees allowed in the building

29 CFR 1926.705 lift-slab operations. (continued)

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(l) Temporary connections

(m) Welding on temporary and permanent connections

(n) Load transfer from jacks/lifting units to building columns

(o) Securing Jacks/lifting units

(p) Prevention of components from disengaging during lifting operations.

29 CFR 1926.705 lift-slab operations. (continued)

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Jack rod

Lifting angle

Seal block

Spearhead framecast in floor slab

Wedge

Wedge block

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1926.705(a) Lift-slab operations shall be designed by a registered professional engineer who has

experience in lift-slab construction.

Lift slab operation

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1926.705 Jack lifting unit

(b) Marked to indicate rated capacity

(c) Not loaded beyond capacity

(d) Two and 1/2 times the load

(e) Designed so they neither lift

nor continue to lift when they are

loaded in excess to rated capacity

(f) Synchronized lifting to ensure

uniform lifting

(g) Leveling device installed ( all

points 1/2 inch tolerance)

(h) Stop device (exceeds 1/2 inch

tolerance)

(i) Manual controls located in central

location - attended by competent

person (must be experienced)

(j) Maximum number of annually

controlled units

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Closure strip

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1926.705 (k) No employee permitted in the building structure while jacking operation taking place -

unless reinforced sufficiently to ensure integrity during erection

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1926.705(K)(2) Under no circumstance, shall any employee who is not essential to the jacking operation be

permitted immediately beneath a slab being lifted

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1926.705(i) Manual lifting controls shall be centrally located

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29 CFR 1926.706 Masonry construction.

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a) Limited access zone• prior to the start of

construction of the wall

• equal to the height of the wall to reconstructed plus four feet, and shall run the entire length of the wall

• on the side of the wall which will be un-scaffolded

• restricted to entry by employees actively engaged in constructing the wall

• shall remain in place until the wall is adequately supported

(b) All masonry walls over eight feet in height shall be adequately braced

29 CFR 1926.706 Masonry construction.

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1926.706(a) Limited access zone

•Established prior to the start of construction•Equal to the height of the wall plus four feet•Unscaffolded side of wall •Remain until adequately supported•Masonry walls over 8 feet adequately braced