Quality Requirements of Pumped Concrete Pumped concrete can be used for most structural concrete construction but is most useful where space for construction equipment is limited or access is difficult. Concrete pumps can be either truck- or trailer mounted and range from small units, exerting pressures from 250 to 300 psi and outputs of 15 … Read more
Drum Type Concrete Mixer Classification This is also called as free fall mixer or gratify mixer. In this type of mixer, concrete is mixed by lifting the ingredients with the help of fixed blades inside a rotating drum and then dropping the material by overcoming the friction between the mixture and the blades. The drum … Read more
Parameters to Consider Before Selecting Concrete Batching and Mixing Plant 1. Capacity of Plant In order to meet the requirement of project specific parameters as mentioned above, a concrete plant of right capacity should be installed. It should take into account various ingredients proposed for use in the mix like, fly ash, admixtures like plasticizer, … Read more
What is Slump Loss in Concrete? Slump value is of great importance when concrete is in its fresh state. Slump value represents the workability property of concrete. Due to its importance, the value of slump is generally specified by the designer. And while working on site, the engineer’s responsibility is to make sure that the … Read more
Sampling of Fresh Concrete To ensure it is representative of the whole truck load, a standard sample consists of scoopfuls taken from different parts of the batch and collected in bucket. Scoopfuls must be taken through the moving stream, as the load is discharged, sampling the whole width and depth (not just the top part). … Read more
Effects of Hot Weather on Concrete Any operation of concreting done at atmospheric temperature above 400C may be put under hot weather concreting. The effect of hot weather may be as follows: Accelerated setting: A higher temperature of fresh concrete results in a more rapid hydration and leads to reduced workability/ accelerated setting. This reduces … Read more
Information to be Supplied by The Producer Before supplying any concrete, the producer should provide the following information to the purchaser. Nature and source of each constituent material Source of supply of cement Proposed proportions or quantity of each constituent/m3 of fresh concrete If any admixture is to be used to produce concrete, then following … Read more
Information to be Supplied by the Purchaser It is recommended that a meeting must be held between the purchaser and the producer of concrete. In the meeting the following points should be discussed. Details of concrete mix Use of concrete Type of structure Performance requirement Notice to be given prior to delivery Delivery rate Purchaser’s … Read more