Methods used for Curing of Concrete

Concrete needs to be cured. There are many different methods of curing. The selection of a specific method will rely on the idea of work and the climatic conditions. The accompanying methods of curing of concrete are commonly embraced.

1. Shading concrete work
2. Covering concrete surfaces with hessian or gunny sacks Sprinkling of water
3. Ponding method
4. Membrane curing
5. Steam curing

Shading concrete work

The object of shading concrete work is to keep the vanishing of water from the surface even before setting. This is embraced for the most part in the event of huge concrete surfaces, for example, street sections.

This is basic in dry climates to shield the concrete from heat, direct sun beams and wind. It likewise shields the surface from downpour. In chilly climate shading helps in protecting the warmth of hydration of concrete in this way forestalling freezing of concrete under mellow ice conditions. Shading might be accomplished by utilizing canvas extended on outlines. This method has a restricted application in particular.

Covering concrete surfaces with hessian or gunny sacks

This is a broadly utilized method of curing, especially for basic concrete. In this way the uncovered surface of concrete is kept from drying out by covering it with hessian, canvas or void concrete packs. The covering over vertical and inclined surfaces ought to be made sure about appropriately. These are intermittently wetted.

The time period will rely on the pace of dissipation of water. It ought to be guaranteed that the surface of concrete isn't permitted to dry in any event, for a brief timeframe during the curing time frame. Uncommon game plans for keeping the surface wet must be made at evenings and on vacations.



~~~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~~~

Some vital factors of building foundation system

The foundation stands for a supporting member of the structure. The purpose of the foundation is to deliver all loads from the walls or columns of the building to the Earth. A foundation is the part of the building that touches the ground directly.

The foundation mainly retains the structure up in order that it never goes down in the supporting ground. Foundation retains the structure so it is not swept away with strong winds like tornadoes. The foundation selection is based on the structural system and the nature of the structure.

The foundation of the structure should be secured from the following factors :

a. Sliding
b. Overturning
c. Sinking or settlement
d. Differential settlement

The foundation systems should satisfy the following vital requirements:-

1. The primary requirement for any structure concerning its load resisting strength is that the structure should be built up in such a manner that the combined dead loads, live loads, horizontal loads like earthquake and wind load are defended, passed and transferred to the ground securely in spite of providing any any structural damage, deflection and distortion.

2. Foundation should be pushed deep into the ground in order that the structure is not influenced with ground movement like swelling, shrinking, freezing. The landslide also should not impact the strength of the building. The structure should be secured from any damage and distress.

3. Foundation base should be inflexible with the purpose of reducing the differential settlement, specifically in a situation when superimposed loads are not consistently dispersed over the foundation.

4. Foundation should be situated in such a manner that its performance remains unchanged because of any unanticipated future forces like earthquake and overloading.

5. The design of the foundations is created to withstand the ultimate loading cases combination against overturning and sliding.

6. Foundation should protect from chemical attack in soil. Groundwater and soil may include several types of chemicals injurious to the foundation concrete, the most aggressive one is sulphates. Sulphate attack can normally be alleviated with sulphate resisting cement. Still proper precaution should be at the time of placing the concrete, by vibrating and curing.

7. Foundation should be taken deep enough to withstand the overturning, despite the fact that the bearing strength of the soil is good at adequate depth. Due to adequate depth, swelling can’t occur.



Read Continue
~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~

Steps included in concrete manufacturing

The concrete quality depends on the manufacturing process of concrete. The manufacturing process involves the following steps :- Batching or measurement of materials, Mixing, Transportation, Placing, Compacting, Curing.

Batching of Material: To maintain the standard of concrete, the quantities of the materials should be perfect. The cement, aggregates and water should have utilized along with 3 percent of batching quantity and the admixture along with the 5 percent of batching quantity. Generally, two types of batching like the volume batch and the weight batch are utilized. The selection of batching method is influenced by the size of job, necessary production rate, and required standards of batching performance.

Volume Batching: Volume batch is suitable for the small works only. The amount of concrete materials is calculated with loose volume by means of standard box alias volume gauge box made of wood or metal. The amount of solid granular material in a cubic meter will be considered as an indefinite quantity. As for instance, the volume of moist sand in a loose condition weights much less as compared to the identical volume of dry compacted sand. Cement is calculated with weight in spite of the methods of batching. The cement is always calculated in terms of weight. The volume of one bag cement (50 kg) is 0.035 m.

Weight Batching: For all types of larger works, weight batching is recommended. There are several types of weight batches.

For small works, manually weight batch is ideal. All the materials are calculated manually by weight. The weight is taken in ordinary weight platform machine. The buckets are applied for large works. The bucket releases the materials directly into the mixture machine. For small to large works, manually or electrically operated automatic batching plants are used.

Mixing: The strength of the concrete relies on the mixing of materials. Standardized mixing process allows to mix the cement to aggregates in a proper way. There should be a coating of cement past on all the aggregate particles and all the materials of the concrete should be mixed into a homogeneous mass when the mixing is performed either by hand or machine.

Transportation of concrete: The concrete can be transported either by normally of mechanically. The concrete is transported manually through pans, wheel carts for small works whereas for large and enormous works, the concrete is transported through buckets or by pumps controlled mechanically.

Placing of concrete: Placing of concrete means arranging the concrete in its desired position. Concrete should be set in position in a perfect way as rapidly as possible within the initial setting time of the cement. Occasionally, admixture is utilized to raise the initial setting time.

Compaction of concrete: Compaction stands for the method for elimination of air voids from the concrete since air voids in concrete creates the vacuum and it reduces the concrete strength significantly. Compaction is performed manually or mechanically. The damping rods are employed in manual system. In mechanical process, vibrators are utilized. The manual compaction system is effective for small size of works. The vibrators are recommended for large size works. Vibrators are categorized into three types, internal vibrators, external vibrators and table vibrators.

Curing of concrete: Curing is vital for strength development and stability of concrete. Curing is started right away after placing and finishing of concrete, and entails maintenance of desired moisture and temperature conditions, both at depth and adjacent to the surface, for elongated periods of time. Properly cured concrete contains a sufficient amount of moisture for continued hydration and formation of strength, volume stability, endurance to freezing and thawing, and abrasion and scaling resistance.

For ordinary Portland cement, the period of curing time is from 7 days to 14 days. In case of rapid cement, the curing time is decreased.

Read more

~~~~~~~~~~~~~~~~~~~~~~~~
Published By
Rajib Dey
www.constructioncost.co
~~~~~~~~~~~~~~~~~~~~~~~~