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Why we use conceal beam in slab design

  Conceal beam A reinforced concrete beam is provided within the slab, whose depth is equal to the depth of the slab. Advantageous of a concealed beam Load Distribution Concealed beams are crucial for distributing loads more evenly across the slab. This distribution reduces stress concentrations at any single point, making the structure more efficient and helping to control cracking. By spreading the loads, the beams ensure that the slab can handle heavier weights, such as those from an overhead water tank, without compromising structural integrity. Aesthetic Appeal Since concealed beams are embedded within the slab, they do not protrude from the ceiling or floor. This results in a cleaner, more aesthetically pleasing finish to the interior space. In residential or commercial buildings, this can be a significant advantage, as it provides a seamless look without visible beams. Increased Headroom By embedding the beams within the slab, the overall height of the room is not reduced. T...
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Portal beam structures

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Portal beam Portal beam structures eliminate the necessity for interior columns, allowing the entire floor area to be utilized without obstructions. This provides greater flexibility in layout and design. Additionally, they facilitate the movement of people, machinery, and goods, which is especially important in factories, warehouses, and retail spaces. This makes the building future-proof, as it can accommodate various uses over time without significant structural changes. Load transfer Vertical loads                                                                                                                                            ...
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BLOCK CASTING IN SRILANKA

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BLOCK CASTING Generally, a ratio of 1:4:5 ( cement : sand : coarse aggregate ) is used for block casting for government construction works in Srilanka. The mixture is poured into moulds of desired shapes and sizes. These molds can vary based on the intended use of the blocks.  The blocks are kept moist for a specific period of time after they are cast.  Curing is an important phase in the manufacture of concrete blocks, and effective processes can result in considerable increases in strength and durability. CURING FOR BLOCK CASTING the blocks should be completely submerged in water for at least 3 days. For at least seven days after removing from the submerged wate r,  hessian cloth   or something similar is used to cover and curing the block to retain wetness and prevent water loss due to hydration. However, for better impacts, it can be extended up to 14 days.
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BLEEDING IN CONCRETING

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Reason for bleeding Segregation is the primary cause of bleeding in the concrete . Heavy aggregate particles go under down during segregation, which causes water to rise to the surface and form a layer. The fine cement particles are also carried by the water's upward transition. Pavements and slabs' top surfaces won't have superior wearing qualities. The molecules bond when water and cement mix, causing a chemical reaction called hydration. This process of hydration is what sets up concrete. If the concrete mix has too much water, there may not be enough cement molecules to properly bond with all the water molecules. The extra water rises to the surface of the concrete as it sets up, forming what is known as bleed water. Excessive bleed water can negatively affect the durability and appearance of the surface of the concrete. Minimising the possibility of concrete bleeding Decreasing the water volume in concrete and Designing the concrete mix properly.  Add more cementitious...
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Segregation of Concrete

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Segregation of Concrete Segregation in concrete is the separation of coarse aggregates from cement paste during the mixing and placement process. As a result, heavier aggregates settle down, and the mixture of cement and water forms on top of the concrete. Factors that Cause Segregation in Concrete 1      1.   High water-cement ratio in concrete Ø   Using a high water-cement ratio in concrete causes concrete segregation, which occurs when concrete is mixed on-site by unskilled workers. Excess water increases the mixture's fluidity. Lighter components, like cement slurry, tend to float towards the surface of concrete causing segregation. 2.      2.  Extreme vibration of concrete   Ø   When concrete is subjected to extreme vibration using mechanical needle vibrators (poker), heavier particles settle at the bottom, and lighter cement sand paste forms on top. 3.       3.  Leakage in the fo...
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Number of blocks in one metre square area (for 300 mm x 150 mm block)

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Usually, we represent the number of blocks in terms of area (m2) rather than length.                                    Consider a block of dimension 300 mm x 150 mm x 100 mm . ( wall thickness is 100 mm )   but for the accurate value we should consider a 10 mm thick mortar layer around the blocks for binding them to each other. Therefore, we consider a single block's length (including mortar) is 310 mm and its height is 160 mm. The area of one block including mortar is 0.31 m × 0.16 m = 0.0496 m2. The number of blocks in one metre square (m2) can be calculated as 1/0.0496 = 20.16 blocks Any area's block count can be determined by multiplying it by 20.16  
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Crushing strength of brick and block

The compressive strength of each prepared brick / block was analysed at the age of 3, 7, 14 and 28 days using a compressive test machine by applying a crushing load.   Brick / Blocks of thickness 75 mm or more when tested for compressive strength shall comply with the following The average crushing strength of 10 bricks shall be not less than 7.0 N/mm 2 The average crushing strength of 10 blocks shall be not less than 2.8 N/mm2                   (The coefficient of variation for the sample shall not exceed 20% )
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