Types of Concrete additives Concrete additives are usually liquid and are only added in very small amounts whilst mixing the concrete. They have a physico-chemical action and are classified into so-called efficiency groups depending on their effect in freshly mixed or hardened concrete. 1. Concrete deflocculants These concrete additives depressurise the water, improving workability while … Read more
The packing density of aggregate gives an indication of how efficiently aggregate fill a certain volume and for that reason is such an important concept in concrete technology.
The process of selecting concrete mixture proportions is a process of optimization of several desirable characteristics based on the project requirements. The characteristics to be optimized are economy, strength, durability, and placeability. 1. Economy. The primary reason for systematically determining mixture proportions is economy. The maximum economy can be achieved by minimizing the amount of … Read more
SUITABILITY OF WATER FOR CONCRETE MIXING OBJECTIVE To assess suitability of water for use in concrete mix. Equipment Measuring cylinder Cube moulds Trowel Tamping rod Vibrating table Testing machine Procedure Analyse water for its chemical compositions as per IS 3025-1964 and compare these with permissible limits given in IS: 456-2000. In case water does not … Read more
What Is Volume Batching of Concrete? Batching of concrete means measuring different ingredients of concrete (i.e. cement, sand, coarse aggregate and water) before mixing it. When this measurement is done on the basis of volume, we call it Volume Batching. Below are mentioned some of important points to remember before adopting volume batching method in … Read more
Types of Chemical Admixtures for Concrete Unlike mineral admixtures, which may be introduced as blended cements, chemical admixtures are typically added during the mixing process of concrete production. Depending upon the requirement, different types of chemical admixtures are manufactured such as air-entraining admixtures, accelerating admixture, water reducing admixture etc. To a civil engineer, description of … Read more
Selection of Concrete Mix Proportions Concrete mix proportions is a process of optimization of several desirable characteristics based on the project requirements. The characteristics to be optimized are economy, strength, durability, and placeability. 1. Economy The primary reason for systematically determining mixture proportions is economy. The maximum economy can be achieved by minimizing the amount … Read more
Mix Concrete Manually Proper mixing of concrete ingredient is very much necessary as it affects the quality of concrete in its fresh state as well as in hardened state. A concrete is said to be well mixed if it fulfills the following requirements. Concrete mix should be uniform in colour Concrete should achieve proper consistency … Read more
Yield of Concrete There are various factors which affect the yield of concrete for a given proportion of concrete ingredients, such as Water-cement ratio Size of aggregate Method of compaction etc. Yield of concrete simply means the actual volume of concrete produced when a given proportion of concrete ingredients are mixed in a certain manner. … Read more
Concrete for long have been specified by nominal mixes (mixes of fixed proportions which ensure adequate strength) and were arbitrarily applied with little regard to the required strength of concrete with water added to ensure workability. But for mixes of desired strength the three variable factors to be considered are: Water cement ratio and consistency … Read more