The following table provides the ASTM standards that apply to concrete masonry units. Architects must specify the CMU weight if a particular weight is required. Heavier units tend to reduce sound transmission, have much higher compressive strengths, and have greater thermal storage capacity however, they are more expensive and cost more to install. Lighter CMUs are less expensive, require less labor to install, and tend to have better fire resistance properties.
There are three classifications of CMU: lightweight (less than 105 lb/ft 3), medium weight (between 105 lb/ft 3 and 125 lb/ft, and normal weight (more than 125 lb/ft 3. The weight of concrete masonry units varies depending on the density of concrete mix used. The standards identify appropriate materials, compressive strength, dimensional tolerance, moisture absorption, and other performance characteristics.Ĭoncrete brick is made from concrete similar to concrete block, but concrete bricks are fabricated in sizes that match traditional clay bricks (i.e. CMU SIZEĬoncrete Masonry Unit (CMU) SpecificationsĬMU manufacturers must conform to ASTM standards when fabricating concrete blocks. While 4", 6", 8", 10", and 12" are the standard sizes, some manufacturers offer other sizes not listed below. The following table provides concrete block sizes in both nominal and actual dimensions. The architect should always attempt to design buildings using the nominal dimensions to the nearest half-block size to reduce waste and labor due to cut blocks. For instance, a 6" CMU is nominally 6" deep while a 10" CMU is nominally 10" deep.Ĭoncrete blocks also come in half-sizes, which are helpful in reducing the need to cut blocks in the field at corners or the end of walls. They are identified by their depth – i.e. Concrete Block - Nominal vs Actual Dimensions Concrete Block (CMU) SizesĬoncrete Masonry Units (CMUs) are manufactured in a variety of sizes.
0 kommentar(er)
