HOW TO DO SAMPLING OF FRESH CONCRETE IN THE FIELD?

How to do sampling of fresh concrete

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

WHAT ARE THE EFFECTS OF HOT & COLD WEATHER ON CONCRETE?

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

HOW TO TEST AGGREGATE FOR BULK DENSITY AND VOIDS?

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

HOW TO REDUCE SAMPLE OF FINE AGGREGATE USING MINIATURE STOCKPILE METHOD?

Miniature Stockpile Method The miniature stockpile method is used for reducing all samples of fine aggregates when the material is in damp or moist condition. If the sample to be split is dry, the material is required to be moistened before using this method. Procedure Place the original sample on a clean, dry plate or … Read more

HOW TO REDUCE AGGREGATE GROSS SAMPLE TO TEST SAMPLE USING MECHANICAL SPLITTER?

Sample Reduction Using Mechanical Splitter Use of a mechanical splitter is considered to be the best method to reduce the gross sample of aggregate. The mechanical splitter splits the sample into two halves as the material passes through the spaces between the bars in the splitter. The same number of each particle size goes into … Read more

HOW TO REDUCE GROSS AGGREGATE SAMPLE TO TEST SAMPLE BY QUARTERING OR CONING METHOD?

What is Quartering? The process of reducing a representative sample to a convenient size, or of dividing a sample into two or more smaller samples for testing, is called quartering. This is a non-mechanical method of reducing a sample. Steps or Procedure for Quartering Place the original sample in the center of a clean, dry, … Read more

HOW MUCH AGGREGATE SAMPLE SHOULD WE COLLECT?

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

HOW TO COLLECT AGGREGATE SAMPLE FROM STOCKPILE?

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

WHAT TO CHECK BEFORE CASTING SLABS?

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