COMPOUNDS FORMED DURING HYDRATION OF CEMENT

Following are the compounds formed during the setting action of cement: Tricalcium silicate (C3S) – 3CaO.SiO2 Dicalcium silicate (C2S) – 2CaO.SiO2 Tricalcium aluminate (C3A) – 3CaO.Al2O3 Tetracalcium alumino ferrite (C4AF) – 4CaO.Al2O3Fe2O3 Compound Percentage by mass in cement C3S 30 to 50 C2S 20 to 45 C3A 8 to 12 C4AF 6 to 10(…)

ENVIRONMENTAL EXPOSURE CONDITIONS OF STRUCTURES

ENVIRONMENTAL EXPOSURE CONDITIONS OF STRUCTURES Sl. No. Environment Exposure Conditions i Mild Concrete surfaces protected against weather or aggressive conditions, except those situated in coastal areas ii Moderate Concrete surface sheltered from severe rain or freezing whilst wet; concrete exposed to condensation and rain, concrete continuously under water; concrete in contact or buried under non-aggressive(…)

PHYSICAL & CHEMICAL PROPERTIES OF OPC OF VARIOUS GRADES

Physical and Chemical Properties of Ordinary Portland Cement (OPC) of Various Grades Type of Cement 33 Grade (IS: 269-1989) 43 Grade (IS:8112-1989) 53 Grade (IS: 12269-1987) PHYSICAL PROPERITES Minimum Compressive Strength, N/mm2 3 day 16 23 27 7 day 22 33 37 28 day 33 43 53 Fineness Minimum specific surface (Blaine’s air permeability)(…)

SPECIFIC GRAVITY OF CEMENT

AIM To determine the specific gravity is normally defined as the ratio between the weight of a given volume of material and weight of an equal volume of water.To determine the specific gravity of cement, kerosene which doe snot recent with cement is used. APPARATUES Le Chaterlier”s flask, weighing balance, kerosene (free from water).(…)

COMPRESSIVE STRENGTH OF MORTAR CUBES

Take 200gm of cement and 600gm of standard sand in the proportion 1:3 by weight) in a pan. (The standard sand shall be of quartz, of light, gray or whitish variety and shall be free from silt. The sand grains shall be angular, the shape of grains approximating to the spherical form, elongated and flattened grains being present only in very small quantities.

FINAL SETTING TIME OF CEMENT

Take 400 gm of cement in a pan. Prepare a neat cement paste by adding 0.85 times the water required to give a paste of standard consistency by the previous test. Start a stop watch at the instant when water is added to the cement. Keep the vicat mould on a non porous plate and fill the cement paste in it. After completely filling the mould, it should be shaken slightly to expel the air. Smooth off the surface of the paste making it level with the top of the mould.

INITIAL SETTING TIME OF CEMENT (IS 4031, IS 269)

STANDARD CONSISTENCY OF CEMENT

The standard consistency is that consistency, which will permit the vicat plunger to penetrate to a point 5 to 7mm from the bottom of the vicat mould when tested as described below.

Tests on Cement