Materials shall conform to the following applicable standards:
- Blended Cements—ASTM C 595.
- Hydrated Lime, Type S—UBC Standard 21-13.
At the time of delivery to the work site, the units shall conform to the physical requirements prescribed in Table 21–4–B. The moisture content of Type I concrete masonry units at time of delivery shall conform to the requirements prescribed in Table 21–4-A.
At the time of delivery to the purchaser, the linear shrinkage of Type II units shall not exceed 0.065 percent.
For particular feature units, dimensions shall be in accordance with the following:
- For molded face units, no overall dimension (width, height and length) shall differ by more than 1/8 inch (3.2 mm) from the specified standard dimension. Dimensions of molded features (ribs, scores, hex-shapes, patterns, etc.) shall be within 1/16 inch (1.6 mm) of the specified standard dimensions and shall be within 1/16 inch (1.6 mm) of the specified placement of the unit.
- For split-faced units, all non-split overall dimensions (width, height and length) shall differ by no more than 1/8 inch (3.2 mm) from the specified standard dimensions. On faces that are split, overall dimensions will vary. Local suppliers should be consulted to determine dimensional tolerances achievable.
- For slumped units, no overall height dimension shall differ by more than 1/8 inch (3.2 mm) from the specified standard dimension. On faces that are slumped, overall dimensions will vary. Local suppliers should be consulted to determine dimension tolerances achievable.
Note: Standard dimensions of units are the manufacturer’s designated dimensions. Nominal dimensions of modular size units, except slumped units, are equal to the standard dimensions plus 3/8 inch (9.5 mm), the thickness of one standard mortar joint. Slumped units are equal to the standard dimensions plus 1/2 inch (13 mm), the thickness of one standard mortar joint. Nominal dimensions of nonmodular size units usually exceed the standard dimensions by 1/8 inch to 1/4 inch (3.2 mm to 6.4 mm).
All units shall be sound and free of cracks or other defects that would interfere with the proper placing of the unit or impair the strength or permanence of the construction. Units may have minor cracks incidental to the usual method of manufacture, or minor chipping resulting from customary methods of handling in shipment and delivery.
Units that are intended to serve as a base for plaster or stucco shall have a sufficiently rough surface to afford a good bond.
Where units are to be used in exposed wall construction, the face or faces that are to be exposed shall be free of chips, cracks or other imperfections when viewed from 20 feet (6100 mm), except that not more than 5 percent of a shipment may have slight cracks or small chips not larger than 1 inch (25.4 mm).
The purchaser or authorized representative shall be accorded proper facilities to inspect and sample the units at the place of manufacture from the lots ready for delivery.
Sample and test units in accordance with ASTM C 140.
Total linear drying shrinkage shall be based on tests of concrete masonry units made with the same materials, concrete mix design, manufacturing process and curing method, conducted in accordance with ASTM C 426 and not more than 24 months prior to delivery.
If the samples tested from a shipment fail to conform to the specified requirements, the manufacturer may sort it, and new specimens shall be selected by the purchaser from the retained lot and tested at the expense of the manufacturer. If the second set of specimens fails to conform to the specified requirements, the entire lot shall be rejected.
MOISTURE CONTENT REQUIREMENTS FOR TYPE I UNITS
|LINEAR SHRINKAGE, PERCENT||MOISTURE CONTENT, MAX. PERCENT OF TOTAL ABSORPTION (Average of 3 Units)|
|Humidity Conditions at Job site or Point of Use|
|0.03 or less||45||40||35|
|From 0.03 to 0.045||40||35||30|
|0.045 to 0.065, max.||35||30||25|
- 1Average annual relative humidity above 75 percent.
- 2Average annual relative humidity 50 to 75 percent.
- 3Average annual relative humidity less than 50 percent.
STRENGTH AND ABSORPTION REQUIREMENTS
|COMPRESSIVE STRENGTH, MIN, psi (MPa)||WATER ABSORPTION, MAX, lb./ft. (kg/m) (Average of 3 Units)|
|Average Net Area||Weight Classification—Oven-dry Weight of Concrete, lb./ft. (kg/m)|
|Average of 3 Units||Individual Unit||Lightweight, Less than 105 (1680)||Medium Weight, 105 to less than 125 (1680-2000)||Normal Weight, 125 (2000) or more|
|1900 (13.1)||1700 (11.7)||18 (288)||15 (240)||13 (208)|
MINIMUM THICKNESS OF FACE-SHELLS AND WEBS
|NOMINAL WIDTH (W) OF UNIT (inches)||FACE-SHELL THICKNESS (FST) MIN., (inches)1,4||WEB THICKNESS (WT)|
|Webs1 Min., (inches)||Equivalent Web Thickness, Min., In./Lin. Ft.2|
|× 25.4 for mm||× 83 for mm/lin. m|
|3 and 4||3/4||3/4||15/8|
- 1 Average of measurements on three units taken at the thinnest point.
- 2 Sum of the measured thickness of all webs in the unit, multiplied by 12 (305 when using metric), and divided by the length of the unit. In the case of open-ended units where the open-ended portion is solid grouted, the length of that open-ended portion shall be deducted from the overall length of the unit.
- 3 This face-shell thickness (FST) is applicable where allowable design load is reduced in proportion to the reduction in thicknesses shown, except that allowable design load on solid-grouted units shall not be reduced.
- 4 For split-faced units, a maximum of 10 percent of a shipment may have face-shell thicknesses less than those shown, but in no case less than 3/4 inch (19 mm).
Bolts embedded in unreinforced masonry walls shall be tested using a torque-calibrated wrench to the following minimum torques:
1/2-inch-diameter (13 mm) bolts—40 foot pounds (54.2 N • m)
5/8-inch-diameter (16 mm) bolts—50 foot pounds (67.8 N • m)
3/4-inch-diameter (19 mm) bolts—60 foot pounds (81.3 N • m)
This section is applicable when it is desired to use tension or shear values for anchors greater than those permitted by Table A-1-E of the Uniform Code for Building Conservation (California Existing Building Code). The direct-tension test procedure set forth in Section 21.702 for existing anchors may be used to determine the allowable tension values for new embedded or through bolts, except that no preload is required. Bolts shall be installed in the same manner and using the same materials as will be used in the actual construction. A minimum of five tests for each bolt size and type shall be performed for each class of masonry in which they are proposed to be used. The allowable tension values for such anchors shall be the lesser of the average ultimate load divided by a factor of safety of 5.0 or the average load of which 1/8 inch (3.2 mm) elongation occurs for each size and type of bolt and class of masonry.
Shear bolts may be similarly prequalified. The test procedure shall comply with ASTM E 488-90 or another approved procedure.
The allowable values determined in this manner may exceed those set forth in Table A-1-E of the Uniform Code for Building Conservation (California Existing Building Code).
Based on Standard Specification C 207–91 (Reapproved 1992) of the ASTM International.
Extracted, with permission, from the Annual Book of ASTM Standards, copyright
ASTM International, 100 Barr Harbor Drive, West Conshohocken, PA 19428
See Section 2102.2, Item 3,Uniform Building Code
Note: See Referenced Standard UBC 21-4
This standard covers four types of hydrated lime. Types N and S are suitable for use in mortar, in the scratch and brown coats of cement plaster, for stucco, and for addition to portland-cement concrete. Types NA and SA are air-entrained hydrated limes that are suitable for use in any of the above uses where the inherent properties of lime and air entrainment are desired. The four types of lime sold under this specification shall be designated as follows:
Type N—Normal hydrated lime for masonry purposes.
Type S—Special hydrated lime for masonry purposes.
Type NA—Normal air-entraining hydrated lime for masonry purposes.
Type SA—Special air-entraining hydrated lime for masonry purposes.
Note: Type S, special hydrated lime, and Type SA, special air-entraining hydrated lime, are differentiated from Type N, normal hydrated lime, and Type NA, normal airentraining hydrated lime, principally by their ability to develop high, early plasticity and higher water retentivity and by a limitation on their unhydrated oxide content.
The four types of hydrated lime for masonry purposes shall conform to one of the following requirements:
- The residue retained on a No. 30 (600 μm) sieve shall not be more than 0.5 percent, or
- If the residue retained on a No. 30 (600 μm) sieve is over 0.5 percent, the lime shall show no pops and pits when tested.
Hydrated lime mortar made with Type N, normal hydrated lime, or Type NA, normal air-entraining hydrated lime, after suction for 60 seconds, shall have a water-retention value of not less than 75 percent when tested in a standard mortar made from the dry hydrate or from putty made from the hydrate which has been soaked for a period of 16 to 24 hours.
Hydrated lime mortar made with Type S, special hydrated lime, or Type SA, special air-entraining hydrated lime, after suction for 60 seconds, shall have a water-retention value of not less than 85 percent when tested in a standard mortar made from the dry hydrate.
Every 90 days, each lime producer shall retain an approved agency to obtain a random sample from a local point of supply in the market area served by the producer.
Standard specifications for steel sheet, zinc-coated (galvanized) or zinc-iron alloy-coated (galvannealed) by the hot-dip process.
|Calcium and magnesium oxides (nonvolatile basis), min. percent||95||95||95||95|
|Carbon dioxide (as-received basis), max. percent|
|If sample is taken at place of manufacture||5||5||5||5|
|If sample is taken at any other place||7||7||7||7|
|Unhydrated oxides (as-received basis), max. percent||-||-||8||8|