When talking of concrete workability, we must consider the fact that the term is subjective and broad which describe how the concrete is mixed, combined, placed, and finished with minimal or no loss of consistency. Workability is the term which describes, strength, quality and appearance even going further to describe the cost of labor for finishing and placement. This article will demonstrate the factors that affect and defines the concrete workability.
Workability may mean different things to different people
When it comes to concrete designs, different agendas and expectations do apply. The engineers want to make a concrete with good strength which can form a strong bond when used with steel. A laborer on the other hand, wants a concrete that can be moved, consolidated, and placed efficiently. A finisher looks for something that is of high quality which will save him/her time during the finishing work. A well-balanced concrete mix which has good workability results in durable products which are of high quality.
Factors affecting concrete workability
Water to cement ratio
Higher amount of cementitious materials results in greater strength with the right amount of water the mixture is easier to consolidate. Less or inadequate water leads to poor hydration process and the outcome is a product which resists placing and finishing. However, a good water to cement ratio should be observed as this serves as a sweet spot for producing a workable concrete.
Different types of admixtures affect the workability of the concrete either by a side effect or a design. For instance, super plasticizers are known to reduce the attraction between the aggregation particles and the cement allowing the formation of mixes which are flowable and without segregation effects.
Aggregates size and shape
An aggregate with a big surface area increases the amount of cement which is needed to cover the whole surface area. Hence, mixes with larger aggregate are more workable compared to aggregate having smaller aggregates. Aggregates which are elongated, angular, and flaky have a decreased workability. Rounded aggregates which lacks angularity fail to form sufficient bond with the cement paste. Crushed aggregate gives the best bond and provides adequate workability. Read more about tools used to remove existing concrete which is for the homeowners those are planning to remove existing concrete before taking any decision further.