KnowYourCement

Scope This method of test covers the procedure for determining the  reactivity of the pozzolana with hydrated lime. Why should we perform Lime Reactivity Test Pozzolana is basically a silica rich non-cementing material. Reactive silica while react with lime and water develops a contentious property. Thus LR test allows us to know how much does this pozzolana is reactive with lime or it is usable or not.  Reaction of Pozzolana with Lime and Water CaO + SiO2 + 2H2O →  Ca(OH)2 + H4SiO4 [i.e. Calcium Hydroxide and Silicic Acid] Ca(OH)2 + H4SiO4 → CaH2SiO4·2 H2O i.e. CH + SH → C-S-H Gel [which is responsible for strength development] Sampling As per IS : 3535 Temperature and Humidity   Temperature Relative Humidity Moulding Room 27 ± 2 °C Not less than 65% Dry Material Water Apparatus Cube Moulds - 50 ± 0.1 mm Balance (1000g, Least Count - 1g) Mixing Apparatus Flow Table Tamping Rod Gauging Trowel (IS : 10086) Measuring Cylinder ( 100ml) Procedure Clean appliances should ...

Scope This standard ( IS : 4031 Part 4 ) covers the procedure  for determining the quantity of water required  to produce a cement paste of standard consistency. Defination of Standard Consistency The standard consistency of a cement paste  is defined as that consistency which will permit  the Vicat plunger  to penetrate to a point 5 to 7 mm from the  bottom of the Vicat mould. Very Simple Defination It is the minimum amount of water required to wet all the cement particles. Sampling As per IS : 3535 Temperature and Humidity   Temperature Relative Humidity Moulding Room 27 ± 2 °C Not less than 65% Dry Material Water Apparatus Vicat Apparatus (IS : 5513) Balance (1000g, Least Count - 1g) Gauging Trowel (IS : 10086) Measuring Cylinder ( 100ml) Procedure Take 400g of cement in a tray. Take about 25% of distilled water i.e. 100g (or 100ml). Mix the water to dry cemen...