ACI Blocks Technical Specifications

ACI Ltd. produces non-load bearing types of CLC blocks: These type of blocks are for insulation purposes only.

ACI Block dimension
Name Type Thickness (cm) Length (cm) Height (cm) Density (kg/m3) Compressive MPa (N/mm2)
ACI 400 Non load-bearing 10 54 25 400 1
ACI 400 Non load-bearing 15 54 25 400 1

Thermal Conductivity Coefficient
R Value
10 cm
K - Thermal Transmission Coefficient
10 cm 15 cm 20 cm
400 0.09 11.1 0.76 0.54 0.41
Technical Broucher


In the market there are two types of lightweight concrete, Cellular Lightweight Concrete (CLC) and Aerated Autoclave Concrete (AAC). Both use air bubbles to lower the block weight while at the same time improving the product.

The difference between AAC and CLC lies in how the air bubbles are generated. AAC bubbles are generated through the use of aluminum powder which generates hydrogen gas bubbles. Such blocks are placed in an autoclave to cure (the autoclave is required because this product has low cement contents). On the other hand, CLC is a process based on making air bubbles in the form of a foam and then mixing the foam into a cement mix. Since CLC have higher cement contents, no autoclave curing is required instead; the finished product is cured like normal concrete.

When compared to AAC lightweight products, CLC air bubbles are significantly smaller, stronger, and each bubble is part of a closed cell system which means ACI block products have lower water absorption - about half of the water absorption as AAC and hollow concrete brick. Compared, CLC increases it strength infinitely under atmospheric conditions and therefore does not have to be protected against humidity.

Comparison between different building materials

Parameters ACI® CLC AAC Concrete Hollow Core Blocks
Basic raw material Cement, sand, water and foam Cement, lime, specially grinded sand, high primary energy input Cement, sand and aggregate
Dry density kg/m³ 400 - 700 425 - 700 1700
Usage Thermal insulation & void filling, Partitions, non-load & load bearing blocks, load bearing non-load & load bearing blocks load bearing and non-load bearing walls
Ageing Gains strength with age (like conventional concrete) No ageing (loses strength, if not protected against humidity) Yes
Thermal conductivity (W/mK) 0.09-0.14 (depending on density) 0.11-0.18 (depending on density) 2.1
Sound insulation Superior than cement block Superior than cement block Normal
Water Absorption (by weight) 16% >35% 20%
Ease of working Superior: can be cut, sawn, nailed, drilled, ordinary mortar/plaster Special mortar (glue) and plaster is required Normal mortar
Eco friendliness Pollution free High energy consumption Pollution free