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
Generally we specify workability of concrete in terms of its slump test value. But sometimes it is also specified by another test called compaction factor. The relation between slump and compaction factor is roughly as follows. Relation Between Slump & Compaction factor Workability Slump in mm Compaction factor Very stiff – 0.70 Stiff 0 to … Read more
A concrete is said to be of good quality, if it is strongest, densest, most workable and most economical for the job for which it is prepared. Amount of cement used in concrete should be low and that of aggregate should be high. If the following general requirements are fulfilled, then we can produce the … Read more
Grading Limit of All in Aggregate Sieve Size Percentage of Passing For All-in-Aggregate 40 mm Nominal Size 20 mm Nominal Size 80 mm 100 – 40 mm 95 – 100 100 20 mm 45 – 75 95 – 100 4.75 mm 25 – 45 30 – 50 600 micron 8 – 30 10 – … Read more
Rules of Thumb on Concrete Mix Adding 4 liters of water to 1 cubic meter of freshly mixed concrete will: Increase slump about 25 mm Decrease compressive strength about 1.5 to 2.0 N/mm2 Increase shrinkage potential about 10% Waste as much as ¼ bag of cement If Freshly Mixed Concrete Temperature Increases 1 degree Celsius: … Read more
Specification For Mechanical Properties of High Strength Deformed Bars & Wires Reference IS-1786-2008-High strength deformed steel bars & wires for concrete reinforcement Type 0.2% proof stress/ yield stress, Min, N/mm2 0.2% proof stress/ yield stress, Max, N/mm2 TS/YS ratio Elongation, %, Min, on gauge length 5.65√A, where A is the cross-sectional area of the test … Read more