Page 37 - HIGHWAY ENGINEERING LABORATORY_FLIP BUILDER

REFERENCE
WORK PROCESS
DOCUMENT

4. Bring the water to boiling, with the mold kept submerged, in

25 to 30 minutes, and keep it boiling for three hours. Remove
the mold from the water, allow it to cool and measure the

distance between the indicator points.
5. The difference between these two measurements
indicates the expansion of the cement. This must not
exceed 10 mm for ordinary, rapid hardening and low heat
Portland cements

Observation And Recording

1. Soundness/expansion of cement = L1-L2
2. L1=Measurement taken after 24 hours of immersion in water
at a temp. of 27 ± 20C
3. L2=Measurement taken after 3 hours of immersion in water at

boiling temperature.
4. Calculate the mean of two values to the nearest 0.5 mm.

DISCUSSION :
a. In the event of cement failing to comply with the specified requirements, a further
test should be made from another portion of the same sample in manner described

above, but after aeration (done by spreading out to a depth of 75 mm and store it
for 7 days in an atmosphere maintained at 27±2°C and relative humidity of 50 to 80
percent).

b. Volume expansion in cement mortar or in cement concrete is caused by the
presence of unburnt lime (CaO), dead burnt MgO and also CaSO4.

c. By Le-chatelier method we can only find out presence of unburnt lime (CaO).

d. Presence of unburnt lime may develop cracks in the cement because of increase in
volume.
e. Free lime (CaO) and Magnesia (MgO) are known to react with water very slowly and

increase in volume considerably, which result in cracking, distortion and
disintegration.
CONCLUSION

a. Give your conclusion from this experimental and explain the result you get.
REFERENCES: Give at least 5 references you refer

Higway Engineering Laboratory page 24