Question

1)in which area is allowed to use sulphate cement ?
2)what is the measure that need to be taken while pouring cement in hot weather?

Answer 1

1.Answer:-

The use of sulphate resisting cement provides excellent protection against the formation of sulpho-aluminates and consequent resistance to concrete against sulphate attack. Very high compressive strength by economic concrete mix design. Very low heat of hydration helps to avoid shrinkage cracks.

Areas where sulphate cement is used:-

1.Foundations, piles.
2.Basements and underground structures.
3.Sewage and Water treatment plants.
4. Chemical, Fertilizers and Sugar factories.
5. Food processing industries and 6.Petrochemical projects.
7.Coastal works.
8. Also for normal construction works where OPC is used.
9.Constructionf building along the coastal area within 50 km from sea.

2.Answer:-

When pouring concrete in hot weather keep an evaporative retarder ready on site in case the temperature gets hotter and water is rapidly evaporating. Use ice as part of the concrete water mix to cool the concrete. Reduce the mixing time once water has been added to the mix.

If temperature is too high to decrease the bad effects on concrete need to go in following way:-

• Have sufficient manpower to manage the concrete when it is being poured and for the finishing process ­— this is not a one-person job.
• If possible, avoid pouring concrete at noon or during peak times for hot air temperature.
• When pouring concrete in hot weather, space control joints at smaller intervals than cold weather concrete joints.
• Use sunshades or windbreaks to reduce possible harsh conditions.
• Plan to have indoor slabs poured after all walls and roofs are built.
• When pouring concrete in hot weather keep an evaporative retarder ready on site in case the temperature gets hotter and water is rapidly evaporating.
• Use ice as part of the concrete water mix to cool the concrete.
• Reduce the mixing time once water has been added to the mix.
• Bags of concrete mix and all equipment needed to pour concrete in hot weather should remain covered or in the shade until the last moment before using.
• When pouring concrete for a slab, first dampen the sub-grade.