Smart Concrete – The newest upcoming technology to detects cracks in concrete earlier

The concrete is extensively used as a composite material for several types of structures but the concrete lacks the strength to resist tension and as a result it can be cracked easily. Therefore, the concrete should be examined thoroughly for cracks and proper and timely repairs should be undertaken so that the quality of the concrete is not deteriorated.

In this way, the safety and stability of different structures are maintained. Another process for determining cracks is to attach sensors to the structure but the installation charge is costly.

Smart concrete technology is the newest concept for examining the health of reinforced concrete structures. The type of concrete is reinforced with carbon fiber comprising of 0.2% to 0.5% of the volume. It can determine the pressure on the concrete structure well in advance. Smart concrete technology has witnessed broad laboratory testing, but has not launched yet.

It becomes functional with the addition of a small amount of short carbon fiber to the concrete with a traditional concrete mixer to change the electrical resistance of the concrete with regards to tension or pressure.

Accordingly, contact among the fiber and the cement matrix is impacted while the concrete is deformed or depressed, thus affecting the electrical resistivity of the concrete volume. Tension is then exposed by calculating the level of electrical resistance.

Smart concrete has the ability to recognize very small structural weaknesses before it gets significant and therefore becomes applicable in checking the internal conditions of the structure, especially after an earthquake.

Besides, identifying small cracks, smart concrete also allows stopping the development of cracks in traditional concrete and reinforce it to make it stronger. Besides, it takes a lot of strength to bend smart concrete, and consume more energy before breaking.

Smart concrete can also be applied in the construction of highways since they can easily find out the weight of the vehicle. Roads constructed with smart concrete can detect the position, weight, and speed of the vehicle.



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Published By
Rajib Dey
www.constructioncost.co
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Detail lists of useful construction tools

Given below, the detailed lists of various useful construction tools and their applications :-

Hoe – It is effective for digging and arranging concrete, cement mortar in head pan. Hoe is also useful for excavating the soil but here the metal plate is set with acute angle to the wooden handle.

Head Pan – It is utilized to transmit materials. Head pan is built with iron to uprise the excavated soil or cement or concrete to the construction site etc. it is mostly found in construction sites.

Masonry trowel – The objective of this tool is to organize cement mortar. It refers to a hand trowel that is applied in brickwork or stonework for the purpose of leveling, dispersion and shaping mortar or concrete.

Measurement Tape – It is employed to examine the thickness, length, widths of masonry walls, foundation beds, excavated trenches etc.

Plumb Bob - It is applicable for verifying the vertical alignment of the structures. It comprises of a solid metal bob attached with the end of a thread. It can also be applied in surveying to level the instrument position.

Wheel Barrow – It is useful for carrying out cement mortar or any materials. Often, it is utilized to estimate the quantities of materials for site level concrete mixing.

Concrete Mixer – It is a machine that is used for blending the concrete perfectly with water, fine aggregate, coarse aggregate and cement at construction site.

Vibrator - It is utilized to vibrate the concrete when pouring is started. For the purpose of workability, water is added to concrete. To get rid of that, vibrators are applied.

Bump Cutter/Screed – The objective of this tool is to level fresh concrete surface particularly in slab concrete.

Wooden Float/wooden rendering float - This tool is useful for providing a flat finish to the plastered area.

Crow Bar - This tool is found in formwork to eliminate nails from boards. Crow bar is also applied for digging the ground and taking out the roots of trees in the ground, nails etc.

Framing Square - This tool is mostly found in Brickwork, Plastering to verify exact angle.

Line Level - This tool is required to verify horizontal level in brickwork, plastering , flooring and tile works.

Flat Pry Bar - This tool is found in shuttering and often utilized to modify the column formwork to align.

Digging bar - This tool is used to divide and unloose the compacted / hard surface area. Digging bar refers to a solid metal rod having pin shape at the bottom. It is also utilized to dig the hard surfaces of ground.

For more information, go through the following link www.civilology.com



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Published By
Rajib Dey
www.constructioncost.co
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How to perform slump cone test for testing the workability of concrete

This construction video tutorial is based on slump cone test. It is one of the most recognized field tests on fresh concrete.

Slump test is undertaken to evaluate the functionality of fresh concrete as well as verify the water ratio and the consistency of concrete from batch to batch.

The instruments which are used in slump test comprise of a mould shaped like the frustum of a cone having the following dimensions :-

Bottom Diameter : 200 mm
Top Diameter : 100 mm
Height : 300 mm
Tamping rod of steel should contain diameter of 16 mm, 600 mm long and rounded at one end.

The following methods are used to work out slump :-

nternally and externally cleanse the inner surface of mould without applying any grease or oil.

Fill the mould with concrete in 4 layers.

Tamp each later with 25 strokes of the rod to get rid of bubbles and voids.

Allocate the strokes consistently over the whole cross-section of the mould.

The rod should infiltrate each bottom-line layer.

By applying a trowel, eliminate surplus concrete after the top layer.

Take away mould gradually and vertically.

The concrete will slump or slide.

Calculate the slump height in mm.

To maintain normal functionality, the slump should not be over 50 mm.

Cleanse the slump cone.

To get more detailed information, go through the following video tutorial.

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Published By

Rajib Dey

www.constructioncost.co

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Details of Cracking in Concrete

If cracks occur in concrete on regular basis, the appearance of the concrete becomes unpleasant as well as the structure of the concrete becomes feeble.

The cracking can be managed with reinforcement and joints. With foul cracking, the reinforcement is uncovered to air and moisture which may cause rust as well as reduce the strength.

Types of Cracks: Two types of cracks occur in reinforced concrete

Pre-Setting Cracks: It develops prior to solidification of concrete whereas it is still executable.

Hardened Cracking: Here, crack develops as soon as the concrete gets solidified.

Pre-Setting Cracks: Pre-setting cracks mainly develop at the time of placing, compaction and finishing resulting from movement of concrete prior to it gets dried.

The following types of pre-setting cracks mainly exist:

Plastic Settlement cracks
Plastic Shrinkage cracks
Cracks resulting from Movement of The Formwork.

When pre-setting cracks occur, examine them carefully so that they can be easily restrained whereas the concrete is still setting.

If these are identified at the initial stage, fixing is done easily with re-compacting, re-trowelling or re-floating the concrete surface.

Plastic Settlement Cracks: These types of cracks develop once the concrete is arranged, whereas it is still plastic. They become larger as concrete dries and shrinks and like to follow the lines of reinforcement.

Prevention
Re-vibrate the concrete.
Re-trowel the surface.

Search for cracks when the concrete is setting. At this stage, these can be easily settled.

Plastic Shrinkage Cracks: Usually cracking occurs in summer but it may also happen throughout winter. Plastic shrinkage cracks become visible in lines, roughly parallel or in a crazed haphazard way. They are generally 300–600 mm long but may be among 25 mm and 2 m in length.

Prevention: Moisten the subgrade and forms and safeguard concrete from the wind. Retain all materials cool on hot days.

Set, compact and cure in quickest possible time on hot days in order that concrete won’t dry out.

As soon as the concrete is condensed, screeded and floated, use a consistent spray film of EVAPORATIVE RETARDANT (Aliphatic Alcohol) to avoid quick loss of surface moisture, then continue with finishing.

It is recommended to set concrete at the cooler times of the day.

Repair Cracks is closed with alteration in the plastic concrete.

For more information, go through the following link onlinecivilforum.com



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Published By
Rajib Dey
www.constructioncost.co
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The process of concrete by weight and volume

atching is defined as the method for computing & combining the various components (cement, fine aggregate, coarse aggregate and water) for the formation of concrete prior to mixing following the mix design.

If this calculation is accomplished based on the volume, it is known as volume batching. Batching is categorized as follow :-

1) Volume batching
2) Weigh batching

Volume batching: In volume batching, the mass of each component is not calculated before batching, rather than there are some fabricated boxes(generally wooden) which are calculated in volume to retain the concrete components.

• This method is normally suitable for small jobs.
• Gauge boxes are applied for estimating the fine and coarse aggregate.
• The volume of gauge box has the similarity with the volume of one bag of cement.
• Gauge bow are also titled as FARMAS.
• They are formed with timbers or steel.
• Normally, they are created as deep and narrow.
• Normally, bottomless gauge boxes are not recommended for application.
• At the time of filling the gauge boxes the material should be filled loosely, no compaction is permissible.

Weigh batching: Weigh batching is the proper and most recognized method of estimating concrete ingredients. Weigh batching is performed in very vital modern concrete batching and mixing plants.

• Batching by weight is better than volume batching in terms of perfectness. Besides, it offers more consistent proportioning. It is always recommended professionally.
• It does not contain uncertainties related to bulking.
• Its equipment’s are divided into 3 general categories.
• Manual
• Semi-automatic
• Fully automatic.
• If batching is done by hand all weighing and batching of concrete are performed by hand. It is suitably for small jobs.
• For semi-automatic batching the aggregate bin gates are opened by operating switches with hand and gates are closed automatically when the material is delivered. This system also comprises of interlock that resists charging and discharging.



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Published By
Rajib Dey
www.constructioncost.co
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