Get Concrete Mix Design Review Checklist

A mix is to be designed for characteristic strength of 50 N/mm2 at 28 days having target strength of 62 N/mm2 at 28 days. 30% of fly ash is to be included by weight of cementitious material. Maximum w/c ratio or w/c + f.a. ratio = 0.4, minimum cement concrete or cement + f.a. content = 400 kg/m3. Slump 50+10 mm.

Water/cement ratio Water to cement ratio (W/C ratio) is the single most important factor governing the strength and durability of concrete. Strength of concrete depends upon W/C ratio rather than the cement content.

The various factors affecting the choice of concrete mix design are: Compressive strength of concrete. Concrete compressive strength considered as the most important concrete property. ... Workability of concrete. ... Durability of concrete. ... Maximum nominal size of aggregate. ... Grading and type of aggregate. ... Quality Control at site.

A properly designed concrete mixture will possess the desired workability for the fresh concrete and the required durability and strength for the hardened concrete. Typically, the volume of a mix is about 10 to 15% cementitious material, 60 to 75% aggregate, and 15 to 20% water.

Desired Properties of Mix The concrete obtained through mix design contain desired properties like workability, durability, setting time, strength, impermeability etc. The design is processed by considering some important factors like water cement ratio, gradation of aggregates etc.

In summary the review of a concrete mix design should focus on answering the following questions: Does the concrete mix meet the performance requirements as outlined on the project specifications, i.e., strength, shrinkage, workability, w/cm ratio, etc.?