mineral / Cementitious / Concrete Masonry Unit
Concrete masonry unit, hollow, various sizes (90mm, 140mm, 190mm, 290mm wall thickness)
Hollow CMUs in 90, 140, 190, and 290 mm series widths; standard unit size is 390 x 190 x 190 mm. Baines Masonry reports concrete unit compressive strength f'uc >= 15 MPa for Betta Block and Dense Weight ranges.
Atlas code
MIN-CEM-CMU-001
At-a-glance signals
Hollow CMUs in 90, 140, 190, and 290 mm series widths; standard unit size is 390 x 190 x 190 mm. Baines Masonry reports concrete unit compressive strength f'uc >= 15 MPa for Betta Block and Dense Weight ranges.
Overview
Executive summary
Hollow concrete masonry units (CMUs) are modular blocks used for structural and non-structural walls. Standard Australian units are 390 mm long x 190 mm high, with common series widths of 90, 140, 190, and 290 mm.
Best when…
- Standard modular size (390 x 190) with common series widths 90/140/190/290 mm
- Baines Masonry units report f'uc >= 15 MPa
- Hollow cores allow reinforcement and services
Top advantages
- 01 Standard modular size (390 x 190) with common series widths 90/140/190/290 mm
- 02 Baines Masonry units report f'uc >= 15 MPa
- 03 Hollow cores allow reinforcement and services
Top limitations
- 01 Properties vary by manufacturer and mix design
- 02 System-specific fire/acoustic ratings depend on wall configuration
- 03 Core filling increases weight and material use
Technical
Physical ·8
- Density
- 1850-2200 kg/m3 CMAA FAQ indicates typical fully core-filled block densities 1850-2200 kg/m3.
- Specific gravity
- 1.85-2.20 Derived from density range 1850-2200 kg/m3.
- Porosity
- 30 %
- Water absorption
- 7.2 %
- UV resistance
- excellent
- Chemical resistance
- good
- pH tolerance
- 3 – 11 alkaline material
- Surface roughness
- 2.5 mm standard moulded finish
Mechanical ·7
- Tensile strength
- 0.2-0.4 MPa Characteristic flexural tensile strength of masonry (perpend failure) per AS 3700 Table 3.2; typical range 0.2-0.4 MPa for standard mortar joints. Source: AS 3700:2018 Table 3.2.
- Compressive strength
- >=15 MPa Baines Fire & Acoustic Manual lists f'uc >= 15 MPa for Betta Block and Dense Weight units.
- Flexural strength
- 0.1-0.3 MPa Characteristic flexural strength of masonry (bed joint failure) per AS 3700 Table 3.2; typically 0.1-0.3 MPa depending on mortar type. Source: AS 3700:2018 Table 3.2.
- Shear strength
- 0.2-0.4 MPa Characteristic shear strength of masonry fms per AS 3700 Clause 3.3.4 for standard mortar joints; typically 0.2-0.4 MPa for unreinforced CMU construction. Source: AS 3700:2018.
- Poisson's ratio
- 0.22
- Impact resistance
- moderate
- Creep resistance
- 0.5 ×10⁻⁶/MPa long-term
Sustainability & Health
Embodied carbon & energy ·3
- Embodied carbon
- 100-130 kg CO2e/tonne Indicative embodied carbon for hollow concrete masonry unit per tonne of material; typical range 100-130 kg CO2e/tonne based on CMAA and ICE Database v3.0 data for concrete block manufacture in Australia. An EPD for Adbri Masonry concrete blocks (EPD Australasia EPD-AUS-0082) reports approximately 118 kg CO2e/tonne for standard hollow block. Source: ICE Database v3.0; EPD Australasia EPD-AUS-0082.
- Embodied energy
- 800-1100 MJ/tonne Cradle-to-gate embodied energy for hollow concrete masonry unit per tonne; typical range 800-1100 MJ/tonne based on ICE Database v3.0 for concrete block (cement-bound). Includes raw material extraction, manufacturing, and transport to gate. Source: ICE Database v3.0 (University of Bath); BRANZ LCA data for Australian masonry.
- Recycled content
- 0-30 % Recycled aggregate content varies by manufacturer; CMAA members commonly incorporate 5-30% recycled crushed concrete aggregate in non-structural units. Structural grade units typically 0-15% recycled aggregate to maintain f'uc >= 15 MPa. Some manufacturers use supplementary cementitious materials (fly ash, slag) at 10-20% cement replacement. Source: CMAA Concrete Masonry Design Manual; Adbri Masonry product data.
Compliance & Fire
Fire performance ·1
- Fire resistance level
- System dependent Fire & acoustic manual provides system-specific FRLs by wall configuration and thickness.
Cost & Lifecycle
Capex & lead time ·3
- Material cost (range)
- $2.50-$6.00 AUD/unit Retail price range for standard hollow CMU across Australian suppliers (Adbri, Baines, Boral); 190mm standard block typically $3.50-$6.00/unit, 90mm series $2.50-$4.50/unit. Source: Australian supplier price lists and AIQS construction cost data 2024.
- Material cost (per unit)
- $55-$90 AUD/m² Installed masonry cost per m² of wall face, supply only (excl. mortar, reinforcement, fill); 190mm wall approximately $55-$90/m² supply. Source: Rawlinsons Australian Construction Handbook 2024, Section 5.
- Market availability
- Widely available nationally Widely available nationally through Adbri Masonry, Baines Masonry, and regional masonry suppliers. Standard 190mm and 90mm series held as stock items. Lead time 1-5 business days for standard sizes. Source: Adbri Masonry and Baines Masonry product availability data.
Service life & durability ·3
- Expected lifespan
- 100 years with proper maintenance
- Maintenance interval
- 10 years inspection and repointing
- Warranty period
- 10 years structural warranty typical
Layer D
Where it's used
Loadbearing walls (single and multi-storey)
Non-loadbearing partitions
Fire-rated wall assemblies
Acoustic barriers
Retaining walls (core-filled and reinforced)
Commercial and industrial construction
Residential construction
Basement walls
Boundary walls
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