IS 2185:2005 Part 1 is the Indian Standard (BIS) for concrete masonry units - specifications: part 1 hollow and solid concrete blocks. This standard (Part 1) specifies the requirements for solid and hollow concrete masonry units used in load-bearing and non-load-bearing walls. It outlines standard dimensions, materials, physical criteria such as compressive strength, drying shrinkage, and water absorption, as well as sampling and testing procedures.
Specifies requirements for hollow and solid concrete blocks used in masonry construction.
Key values for concrete block classification, dimensions, strength grades, durability limits, and sampling criteria.
| Reference | Value | Clause |
|---|---|---|
| Block Density Classification (Grade A)— Based on oven-dry density. | > 1500 kg/m³ | Cl. 4.2 |
| Block Density Classification (Grade B)— Based on oven-dry density. | ≤ 1500 kg/m³ | Cl. 4.2 |
| Dimensional Tolerance (Length/Width) | ± 5 mm | Cl. 5.2 (Table 1) |
| Dimensional Tolerance (Height) | ± 5 mm | Cl. 5.2 (Table 1) |
| Min. Face Shell Thickness (Hollow)— For blocks with width > 75 mm. | 25 mm | Cl. 5.3.1 |
| Min. Web Thickness (Hollow) | 20 mm | Cl. 5.3.2 |
| Min. Avg. Compressive Strength (Grade 3.5)— Average of 3 units on net area. | 3.5 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 4.5)— Average of 3 units on net area. | 4.5 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 5.5)— Average of 3 units on net area. | 5.5 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 7.0)— Average of 3 units on net area. | 7.0 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 8.5)— Average of 3 units on net area. | 8.5 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 10.0)— Average of 3 units on net area. | 10.0 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 12.5)— Average of 3 units on net area. | 12.5 MPa | Cl. 6.2 (Table 2) |
| Min. Avg. Compressive Strength (Grade 15.0)— Average of 3 units on net area. | 15.0 MPa | Cl. 6.2 (Table 2) |
| Min. Individual Block Strength— Acceptance criteria for any single block from the sample. | ≥ 80% of specified avg. strength | Cl. 6.2 |
| Max. Water Absorption (Avg. of 3) | 10 % by mass | Cl. 6.3 |
| Max. Drying Shrinkage | 0.06 % | Cl. 6.4 |
| Max. Moisture Movement | 0.09 % | Cl. 6.5 |
| Sampling Scale (Visual & Dims)— Sample size for visual and dimensional inspection. | 8 blocks / 10,000 | Cl. 8.2.1 (Table 3) |
| Sampling Scale (Strength Test)— Sample size for compressive strength test. | 3 blocks / 10,000 | Cl. 8.2.1 (Table 3) |
| Sampling Scale (Density Test)— Sample size for block density test. | 3 blocks / 10,000 | Cl. 8.2.1 (Table 3) |
BIM-relevant code. See the BIM Hub for ISO 19650, IFC, and LOD/LOIN frameworks used alongside it.
| Parameter | IS Value | International | Source |
|---|---|---|---|
| Minimum Compressive Strength (Net Area) | 3.5 N/mm² (for lowest loadbearing grade) | 2000 psi (~13.8 N/mm²) (average of 3 units) | ASTM C90-23 |
| Maximum Water Absorption | 10% (by mass) | Varies by density, e.g., 13 lb/ft³ (~208 kg/m³) for Normal Weight concrete | ASTM C90-23 |
| Maximum Drying Shrinkage | 0.06% | 0.065% | ASTM C90-23 |
| Dimensional Tolerance (Length/Width) | ±5 mm | ±1/8 in. (±3.2 mm) | ASTM C90-23 |
| Dimensional Tolerance (Height) | ±3 mm | ±1/8 in. (±3.2 mm) | ASTM C90-23 |
| Density Classification (Normal/Heavy) | Grade A: > 1500 kg/m³ | Normal Weight: ≥ 125 pcf (≥ 2000 kg/m³) | ASTM C90-23 |
| Minimum Face Shell Thickness (150-200mm block) | 25 mm | 1.25 in (31.8 mm) | ASTM C90-23 |