Sometime it may happen that, the aggregate available at site is not conforming to the desired grading. In such case two or more aggregates from different sources may be combined to get the required grading. Fineness modulus value can be used as a technical way to blend coarse aggregate with fine aggregate to produce desired … 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
Objective Determination of unit weight or bulk density and void of aggregates. Equipments Name Capacity 1. Balance Sensitive to 0.5% of weight of material 2. Cylindrical metal measure Of 3 litre capacity (for fine aggregate) Of 15 litre capacity (for aggregate upto 40mm) 3. Tamping rod 16 mm dia. and 60 cm long Sample Preparation … Read more
The amount of aggregate sample to be collected is dependent on the maximum nominal size of aggregate. The quantity of aggregate sample should be of such amount, so that the required test can be performed to judge its quality. Sample of aggregate is collected using a sampling scoop. Collect a no of increments (at least … Read more
Sampling is of equal importance to testing and a man collecting samples should use every precaution to obtain samples that will show the true nature and condition of the materials which they represent. Aggregate Sampling from Stockpile Using a front end-loader, dig into the stockpile and set aside small pile of 10 to 15 ton … Read more
Checking of Concrete Slabs Ensure that the position of the cover blocks is intact and not disturbed during concreting operations. In case concrete is made at the site, closely supervise proper batching of ingredients, the water content, and the mixing and testing of fresh concrete. Make sure the beams are first cast in layers and … Read more
Checking of Concrete Slab Check all the concealed electric conduit work, junctions and electrical points, the positions of fan points, and MS boxes as per your electrical layout plan. Check the reinforcement and get an approval from your RCC consultant. Check the standby arrangements made for water in case of power failure. Consult your RCC … 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