Why Use Clean Sand for Mortar?

Contaminated sand will not bind to the cement, therefore weakening the mortar. Also sand with a high percentage of clay or silt will weaken the mortar, as clay or silt contains a lot of fines that need to be covered by cement for proper bonding.

Why use fresh cement for mortar?

The longer the storage time of cement, the lower its strength. Cement stored for about 6 months will show 30% less strength than fresh cement. The strength of mortar is very important for a good masonry job as it affects the overall quality of the building.

Mortar Mix - Did You Know It?
Mortar Mix – Did You Know It?

Why mix dry ingredients (ie sand and cement) before adding water?

The particles of wet sand have a tendency to stick together and hence the cement is hindering the covering of them. This results in a non-uniform mixing that is reducing the quality of the mortar, as each sand particle should ideally be completely covered with cement.

Also, mixing water with sand and cement at once makes it extremely difficult for workers to mix the mortar.

Why protect the mortar mixing place from wind, rain and sunlight?

Wind and sunlight are penetrating the water from the mortar and speeding up the hardening process before it is used. This makes the mortar useless for any purpose. Rain adds water and the mortar also becomes unusable.

Why not use or reuse mortar that has already been set?

In hardened mortar, the hydration process of cement has started and the bond between cement and sand is being destroyed by mixing it again. This bond cannot regain strength by simply adding fresh water to the mortar.

Because cement mortar sets relatively quickly (about 30 minutes), it should never be mixed in large quantities.

Er. Mukesh Kumar

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Er. Mukesh Kumar is Editor in Chief and Co-Funder at Civil Engineering Website. Mukesh Kumar is a Bachelor in Civil Engineering From MIT. He has work experience in Highway Construction, Bridge Construction, Railway Steel Girder work, Under box culvert construction, Retaining wall construction. He was a lecturer in a Engineering college for more than 6 years.