Concrete Block Specifications
Discussion of Specifications
General notes about the specifications and the reasons for them are listed here in general statements. Use this as a guide when choosing the correct selection of statements that apply to your job from the actual specifications.
A.S.T.M. C-90-96, UBC Standard 21-4
These specifications are based on A.S.T.M. C-90-96. When particular features are designed such as weight classification, higher compressive strengths, surface textures, finish, color, fire resistance, insulation, acoustical properties, or other special features; such properties should be specified separately and clearly by the purchaser or architect. However, Elliott Block should be consulted as to the availability of units having the desired features.
Type of Block
Selecting the proper type of block for your job is very important. Texture means you are using slump block, split face, or precision block. Specify and indicate the proper type or types to be used and their locations.
A sample panel is important because it serves as a visual aid for workmanship for the masonry contractor and architect. This helps to eliminate later discussion about workmanship standards. In lieu of the sample panel, begin work in the most obvious section designated by the architect and this will serve as the sample panel.
Certificates of compliance with all applicable ASTM and UBC standards shall be submitted on all products specified.
Colored block usually has to be manufactured, especially on large projects. It is also one of the first items to be installed. To avoid a possible delay in construction, select the block color before bidding the job. This will take the guesswork out of the bidding process because the cost of color in block does vary. This also alerts the general contractor to notify the masonry contractor, who in turn should be expedient in placing the order with his supplier.
Hi-stress masonry cost more than the regular A.S.T.M. C-90-96. Be sure to specify the f’m required. If you want a 3,000 P.S.I. f’m you will need a block with a minimum P.S.I. of 3,750, a grout with a 4000 P.S.I. and a type M mortar.
SPECIFICATIONS FOR CONCRETE MASONRY
Loadbearing concrete masonry units shall conform to UBC Standard 21-4, Grade N, and type ll, ASTM C 90-96. All units shall be Normalweight, Mediumweight, or Lightweight, 1900 net psi, as manufactured by ELLIOTT BLOCK. Texture (Precision; Split Face; or Slumped) ELLIOTT color (Grey, Tan, ect.) or approved equal by Architect.
PORTLAND CEMENT shall conform to A.S.T.M. C-150, UBC 19-1.
MORTAR shall be freshly prepared and uniformly mixed in the ratio by volumes, 1 part cement, _ part Hydrated Lime, 3 parts sand, and shall conform to A.S.T.M. C-270, UBC 21-15 mortar to match color of block.
GROUT shall be a fluid consistency and mixed in the ratio by volumes, 1 part cement, 3 parts sand, or 1 part cement, 3 parts sand, 2 parts pea gravel.
REINFORCING STEEL shall be deformed bars conforming to A.S.T.M. A-615 except that 1/4″ ties may be plain bars. Wire reinforcement shall conform to A.S.T.M. A-82.
Walls shall be laid true and plumb. Provisions shall be arranged for all adjoining construction. Construct a 4’x6’ sample for workmanship, joint treatment, pattern and color of mortar for approval. Tuck point all holes 1/8″ or more.
ELLIOTT BLOCK COMPANY’S
SUGGESTED BLOCK MASONRY SPECIFICATION
CONCRETE UNIT MASONRY
PART 1 – GENERAL
Division 1 requirements, Drawings, General Conditions, Supplementary General Conditions, and Special Conditions apply to this section.
Deviations from the plans and specifications shall not be made without the written approval of the architect and/or engineer.
1.02 SCOPE OF WORK
|A. Furnish and install concrete masonry units, mortar, grout, and masonry reinforcing steel. Provide equipment necessary for their installation.|
B. Install items furnished by others: bolts, anchor bolts, shelf angles, and built-ins.
C. Arrange for adequate bracing, forming, and shoring required in conjunction with and in the course of constructing the concrete masonry.
D. Advise the general contractor as to the position of all dowels for the masonry. The general contractor shall be responsible for the placement of all dowels in any adjoining construction.
E. Arrange for inspections.
1.03 RELATED WORK SPECIFIED ELSEWHERE
|A. Related sections:|
1.04 QUALITY ASSURANCE
B. Sample Panel:
1.05 PRODUCT HANDLING AND STORAGE
|A. Materials of this section shall be protected to maintain quality and physical requirements.|
B. All masonry units shall be stored on the jobsite so that they are protected from rain, stored off the ground and kept clean from contamination.
C. Handle units carefully to avoid breakage and damage to finished faces.
1.06 EXTREME WEATHER CONDITIONS
Cold Weather Conditions (40ºF or below):
|A. Wet or frozen units shall not be laid. Temperature of units when laid shall not be less than 20ºF.|
B. Aggregates and mixing water shall be heated to produce mortar and grout temperatures between 40ºF and 120ºF.
C. Maintain mortar temperature on boards above 32ºF.
PART 2 – MATERIALS
2.01 CONCRETE MASONRY UNITS
|A. Loadbearing concrete masonry units shall conform to UBC Standard 21-4, Grade N, and type ll, ASTM C 90-96. All units shall be Normalweight, Mediumweight, or Lightweight, 1900 net psi, as manufactured by ELLIOTT BLOCK. Texture (Precision; Split Face; or Slumped) ELLIOTT color (Grey, Tan, ect.) or approved equal by Architect.|
|Description (Size, Texture, Wt.)||Std., Open end, etc.||Color|
2.02 MORTAR AND GROUT COMPONENTS
|A. Cement: Cement shall be portland cement conforming to ASTM C-150, Type I, II, III (UBC 19-1).|
B. Aggregates: Aggregates for mortar conform to ASTM C-144. Aggregates for grout conform to ASTM C-404.
C. Lime: Hydrated lime shall conform to ASTM C51 (UBC 21-13).
D. Water: Clean and free from deleterious substances.
E. Sand: Comply with the “Standard Specifications for Aggregate for Masonry Mortar”, ASTM C-144, except provide natural sand graded From coarse to fine within the following limits:
F. Pea Gravel: Graded with 100% passing the 3/8″ sieve and not more than 5% passing the No. 8 sieve.
2.03 MORTAR AND GROUT MIXES
|A. Mortar (ASTM C-270, UBC 21-15):|
B. Grout (ASTM C476, UBC 21-19): 1 part portland cement; 2 1/4 to 3 damp loose sand; 1 to 2 parts course aggregate.
2.04 REINFORCING STEEL
|A. Reinforcing bars shall comply with ASTM A615, Grade 60, except that Number 4 and smaller bars shall be Grade 40.|
PART 3 EXECUTION
3.01 GENERAL WORKMANSHIP
|A. Lay block in running bond with mortar for bed joints flattened, furrowing of bed joint mortar will not be permitted. Head joints solidly filled with mortar for a distance in from the face of the wall or unit not less than the thickness of the longitudinal face shell. Shove blocks into place to compact the head joint mortar and improve the bed joint. Vertical cells shall have vertical alignment sufficient to maintain a clear, unobstructed continuous vertical cells for grouting. Remove overhanging mortar and debris from cells before grouting. Install hollow metal frames as indicated.|
B. Accurately place reinforcing steel as shown on the drawings, positively secured and supported in such a manner that no movement occurs when the grout is poured. Reinforcing and tie wires shall be embedded in the grout. The thickness of the grout between masonry units and reinforcing shall be a minimum of one bar diameter.
C. Damp cure masonry work for a period of not less than 7 days after the work is completed. Make provisions for curing on Saturdays, Sundays and holidays.
D. Replace defective blocks and blocks cut when cylinder is removed with new masonry which matches the existing block.
|A. Exposed vertical and horizontal joints shall be solidly filled as the work progresses. After joints are thumbprint firm, they shall be tooled to a tight, smooth concave surface with an approved tool. Joint width shall be 3/8″ inch, 1/2″ for slump block.|
B. Control of expansion joint shall be continuous through the mortar and masonry, at a maximum of 40’-0″, unless shown otherwise. Horizontal reinforcement, except at roof or floor diaphragm, shall be continuous through the control joint.
|A. Top of grout pour should be kept damp to prevent too rapid drying during hot or drying weather and drying winds.|
|A. Immediately after the wall has been fully grouted, the scum and stains which have percolated must be cleaned from wall surface.|
B. Keep area clean and neat. After completion of grouting, clean up and remove resultant debris from the site.