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Types of Pipes in Drainage System of Residential Building

We use various types and different sizes of drainage pipes in the different locations for various purpose in residential building’s drainage system. Sometimes size/diameter of pipe is not shown in the drawing. In that situation we use typical size of pipe for a particular purpose. Because size of pipe doesn't vary much in residential building. Types and size of drainage pipes is also a much asked question in job interviews. I also faced this question once. That is why I'm writing about this in this post.

This post will answer the following questions -
  • what are the different types of pipes used in the drainage system of residential building.
  • what sizes of drainage pipes are used in residential building’s drainage system?
drainage system in residential building
Now lets find the answer of above questions.

We use following types of drainage pipes in residential building -
  • Waste pipe/Waste stack,
  • Soil pipe/Soil stack,
  • Rain Water Pipe, and
  • Vent pipe.
The descriptions of each type of drainage pipe below will give you a complete view of drainage system of a residential building -

Waste pipe: This is a 4 inches dia pipe go vertically along building height. Waste water from bath-tub, basin, shower, kitchen etc. go through this pipe. Waste pipe is also called waste stake.

Different size of waste water pipe at different place -
Floor trap to waste stack - 4 inches.
Basin to floor trap - 1.25 inch.
Shower/bath tub to floor trap - 1.5 inches.
Kitchen sink to floor trap - 2 inches.

Soil pipe/Soil stack: Dirt from water-closet is discharged through this type of pipe. Size of soil pipe is 4 inches. It is placed parallel with waste stack.
Size of connecting pipe between W/C and soil stack is 4 inches.

Rain water pipe: In short, it's expressed by RWP. It is also a vertical pipe go along building height. Rain water from roof and other open places go through it.
For removing rain water from veranda we use 2 inches dia pipe and connect it with RWP.

Vent pipe: Vent pipe is used to remove bad air from soil stack and waste stack. Typically 2 inches dia pipe is used for this purpose. Vent pipe is the short form of ventilation pipe.
Other than these pipes, there are also some other pipes of 6 inches dia we use below ground level. Those are main drainage line. These main drainage line collect dirty liquids from soil stack and waste stack separately and discharge to desired destination. Such as, collected liquid from soil stack discharges to septic tank and from waste stack to municipality drain.



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Portland Cement Properties

We generally use hydraulic cement in our construction which is best known as Portland cement. Cement properties vary in different "types of cements" because of different percentage of "cement ingredients". To construct economical concrete structure or cementious product it is essential to know the properties of cement.

Cement properties can be categorized into two types. Chemical properties and Physical properties. For quality controlling purpose of concrete or cementing materials, chemical properties are normally ignored and physical properties are taken into consideration. In this post we are going to share physical properties of Portland cement.

Physical Properties of Portland Cement

Cement has following physical properties -
  • Fineness
  • Soundness
  • Consistency
  • Setting Time
  • Compressive Strength
  • Heat of Hydration, and
  • Specific Gravity

Properties of Portland cement

Fineness

Fineness of cement means the particles size of cement. It affects the hydration process of cement. That means it affects the rate of strength gain of cement.

Soundness

Cement has a trend to shrink when it is hardened. This is called soundness of cement. Good soundness cement doesn't shrink after hardening.

Consistency

Consistency means the required water to produce plastic cement paste for particular cement. Thus one can know the water-cement ratio for better workability of mix.


Setting Time

As soon as water is mixed with Portland cement, hydration process starts and it begins to set. Cement has two setting time, initial-setting time and final-setting time. In construction, initial-setting time shouldn't be too early and final-setting time shouldn't be too late. Normally, initial-setting time is 30 to 45 minutes and final-setting time is below 10 hours.

Compressive Strength

Cement has three types of strengths. Compressive strength, Tensile strength and Flexural strength. However, compressive strength is taken into consideration, the rest can be ignored. For knowing compressive strength of cement, Only cement paste can't be tested. For this purpose, either cement-sand mortar cubes or"cement-concrete cubes" are made. The testing result of cubes can be affected by several things such as water-cement ratio, curing and dampness of cubes during testing. Minimum compressive strength result for 3 days mortar cube should be 16 N/mm2 and for 7 days cube should be 22 N/mm2.

Heat of Hydration

Cement reacts as soon as the water is added. It is called hydration. During hydration cement generates heat. This is the Heat of Hydration. Heat of Hydration is influenced by several things. Such as Cement’s ingredients, fineness of cement and water-cement ratio, etc. During large volume concreting cement creates much heat in the center of concrete structure. This extreme heat can affect the quality of concrete. On the other hand, Heat of Hydration can be helpful during cold weather concreting.

Specific Gravity

Specific Gravity of cement is necessary for calculating the mass for desired volume of cement. The Specific Gravity of normal type of cement is 3.15. 

Your Turn
Which cement property/properties do you consider most when choosing cement for you structure?
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Cement Ingredients and Their Functions

Cement is widely used building material in civil construction industry nowadays. When we say cement, we normally mean Portland cement. Different "types of cement" has different percentages of its ingredients. However, typical cement is composed of following ingredients.

Building construction, Cement ingredients, Civil Construction


Typical cement ingredients and their functions

 

Cement ingredients -

* Calcium Oxide (Lime)
* Silicon Dioxide (Silica)
* Aluminum Oxide (Alumina)
* Calcium Sulphate
* Iron Oxide
* Magnesium Oxide
* Sulphate
* Alkalis

Calcium Oxide: It is the main ingredient of cement. 61% to 67% of the mass of cement is Calcium Oxide. it is expressed by CaO. In general, we know the calcium Oxide as lime.
Function: It makes cement sound and provides strength to cement.

Silicon dioxide: It is also a major ingredient of cement. It is known as silica. It holds 19-23% of cement mass. It is chemically expressed by SiO2.
Function: The function of silica is also to give strength to cement.

Aluminum oxide: It is called alumina. The chemical name of it is AI2O3. Cement contains 2%-6% alumina of its mass.
Function: It adds quick-setting property to cement.

Calcium Sulphate: It's chemical name is CaSO4.
Function: It helps to increase the initial setting time of cement.

Iron Oxide: It is also called Ferric Oxide. Cement has 0.5%-6% iron oxide of its mass. Iron Oxide's chemical name is Fe2O3.
Function: It provides color and hardness to cement. It also provides some strength to cement.

Magnesium Oxide: Magnesium Oxide is expressed by MgO. It also provides color and hardness to cement.

Sulfate: It is also called Sulphur. It holds 1.5%-4% of the mass of cement. The chemical name of Sulphur is S.
Function: A very small quantity of Sulphur in the cement makes it (Cement) sound.

Alkalis: A very small quantity of this may present in the cement.

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How to Make RCC Bottom Slab of UGWT

In last post we discussed "Earth Excavation techniques and precautions of Under Ground Water Tank". Today we will make the RCC bottom slab of that UGWT.
under ground water tank
Preparation:
Before starting bottom slab work we need to prepare the base. Properly compact and level the base soil. Make 3 inches brick soling above base soil. See "how to make brick soling". After finish brick soling make 2 inches thick PCC. See "how to make PCC".

Materials:
We need the following materials to make the bottom slab of RCC under ground water tank -
* Steel bar (as per drawing)
* Binding wire
* Concrete ingredients (cement, sand and stone chips)
* Water proofing sheet
* Foam lube (concrete admixture) etc.

Form work:
Making Form work for UGWT is simple. Just fix side shutter all around water tank. The height of side shutter will be 1 foot and 4 inches. Since our bottom slab height is 10 inches and chamber height is 6 inches so the formwork height is 1 foot and 4 inches. See the above image.

Reinforcement:
In construction project you should have a complete set of drawing sheets. In those drawings you must have a "structural drawing sheet" for water tank's reinforcement details. The sheet will look like the above image with details reinforcement. Place the bottom slab reinforcement as per drawing. And also place the water tank's wall reinforcement as shown in the drawing. At last, place chamber reinforcement as shown in the above image. One thing I would like to clear here that is the chamber. What is the chamber? Why is it provided? Chamber is a sloped concrete portion provided in the corner of wall and bottom slab junction of water tank. It is provided to prevent water penetration through joint. See the image above.

Concrete Casting:
For this small quantity of concrete volume we normally depend upon mixture machine. See "how to mix concrete with mixture machine". You may also like to read "how to control quality when mixing concrete with mixture machine". Add 200 milliliter foam lube with one bag cement mixture or as per manufacturer instruction.

We suggest, do chamber casting simultaneously with bottom slab. If you do so there will be no joint in the bottom slab and wall junction. And the Joint will be in wall above chamber's top portion. And we will provide water proofing sheet in the upper portion of the chamber where joint will be. So it is better to keep the concrete joint in the water tank's wall. Another thing, placing water proofing sheet in the joint of wall and bottom slab is difficult because of chamber rod.

Following these small techniques you can make the water tank completely leakage proof. Leakage in under ground water tank is difficult to repair. So be careful.


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Earthwork Excavation for Under Ground Water Tank

In this article we are discussing about how to excavate earth and what precautions should be taken for constructing water reservoir below ground for a building.
Under Ground Water tank Assumption for Under Ground Water Tank (UGWT)-

>> Clear length: 30 feet,
>> Clear width: 6 feet,
>> Clear height: 7 feet.

Clear length, width and height means the inside dimension of water tank.

Wall thickness of water tank: 10 inches.

All right, now we have a drawing sheet showing all the above dimension of water tank and reinforcement details. Now, we can start earth excavation for UGWT.

Dimension Calculation for earth excavation


Total water tank length including water wall is 31 feet and 8 inches (31 feet + 10 inches + 10 inches). We need one feet clear space around water tank for easily moving labors during shuttering work. So the excavated length will be 33 feet and 8 inches (water tank length + both sides clear space).

Similarly, the excavated width will be 7 feet and 8 inches.

Now lets calculate the excavated height of water tank. We have 7 feet clear height of water tank. So the excavated height will be 8 feet and 9 inches (clear height + top slab thickness + bottom slab thickness + PCC thickness + soling thickness). Here we take top slab thickness is 6 inches, bottom slab thickness is 10 inches, PCC is 2 inches and soling is 3 inches (all these dimensions are shown in the drawing). During calculation of excavated height of water tank, one thing you should take into account that is ground level. In this example, we assume water tank's top-level is on ground level. If water tank's top-level is 1 feet above the ground level (+1) then the excavated height will be 1 feet less.

During excavation, maintain a slope in side soil because straight cut soil can easily break down. Also give support to side soil to prevent from break down. Be careful during excavation so that the excavated level doesn't go below footing. It can be harmful for building. And also keep a Mud Pump ready because there may be a possibility to come up water during excavation.

After finishing excavation check whether the base soil hard enough. If the soil is loose then use macadam and compact the soil. The rest of the work of constructing water tank should be started as soon as the excavation done. Because there is a possibility to break down the side soil.

Avoid the water tank work during rainy season. It is better to start the water tank work simultaneously with footing work. It can save you from extra earth excavation and from some hassle.

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Quality Checklist for Brick Work - Supervision

Brick wall is made by joining bricks with cement mortar. We make brick wall to arrange floor area for different purposes of uses. It also provides privacy to dwellers. Properly made brick wall increase the beauty of building and rooms. Today we are going to publish a quality checklist during making brick wall.
BriCk wall Checklist for quality
Below is a quality checklist for making brick wall -

Brick quality:
Of course for making quality brick wall we have to choose quality bricks. See "how to identify quality materials on site" for choosing quality bricks.

Soaking:
Make sure bricks are soaked for at least 12 hours in clean water to remove salt and other chemicals from bricks.

Cement Mortar:
Make sure cement mortar is mixed properly in dry condition on a clean place.
Check mixing ratio is properly maintained.
Check clean drinking water is mixed.
Make sure the mixed mortar is used within one hour after adding water. If you want, you can maintain register for tracking mixing time and ratio.

Wall:
Check wall is located as per drawing at the time of making brick layout.
Don't make wall above 5 feet in same day.

Door and Window opening:
Check door and window location are kept as specified in the drawing.
Make sure openings are bit bigger than specified in drawing.

Brick joint:
Don't make bricks joint bigger than half-inch.
Make sure vertical joints in alternate courses are truly vertical depending on "types of brick bond pattern".
Check horizontal joints are truly straight.

Bricks with RCC face:
Check RCC surface is Properly chipped and applied grout on surface where brick will touch with.

Alignment:
Check vertical alignment of every three courses of brick wall with plumb bob.

Lintel and sunshade:
Check lintel and sunshade above opening are made as per design specification.
Check sunshade dimensions are kept as per drawing.
Make sure cat door opening is kept in wall or false ceiling as specified in the drawing.

Curing:
Check brick wall is cured for at least seven days with clean drinking water.

After making brick wall we are to start groove cutting for electrical and plumbing piping. But this work should not be started before ending curing period of wall. Another thing, if you think concrete and brick joints may develop cracks in plaster then you should use wire mesh there before doing plaster.
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Types of Paint Finishes

After drying paint work we can see various degree of shiny/glossy effect on paint film. There is a tool, named Glossymeter, available in the market to measure this effect of paint finish. Considering this effect, paint finishes can be divided into four main categories.

Types of Paint Finishes
Painting


Types of Paint finishes


Main four types of paint finishes are -

  • Matt Finish
  • Satin Finish
  • Semi-Glossy Finish and
  • Glossy Finish

Matt Finish: This paint finish has the lowest glossy effect. If we measure this paint finishes with Glossy-meter at 60 degree angle we will get the reading below 5. This type of finish is also called Matte finish.

Satin Finish: This type of paint finish has silk like glossy effect. This finish gives a soft glow on painted surface. It is more durable than Matt finish and has wash-ability. The Glossy-meter reading of this paint finish is between 6 to 20. This type of finish also called Egg-Shell finish but sometimes it is categorized as different type that I'll discuss end of this article.

Semi-Glossy Finish: The glossy effect of this paint finish is more than Satin Finish. It is fairly shiny and the Glossy-meter reading of this finish type is between 20 to 70. It is very durable and appropriate for high traffic and moisture area.

Glossy Finish: With more than 70 Glossy-meter reading this type of paint finish has excellent glossy effect. This is most durable paint finish. And it also has the high wash-ability.

Beside these four types of paint finishes many paint companies also refer following types of finishes -

Flat finish: Although this type of paint finish is sometimes used synonymously with Matt finish, it has no shiny effect at all. It also doesn't have wash-ability. And durability of this paint finish much less than others. That's why it should be used in less important area.

Egg-shell finish:
Actually it is satin finish. But some paint companies divide less glossy effect Satin finish as Egg-shell.


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Typical Reinforcement Placement of RCC Staircase


Placement of RCC staircase reinforcement



Stair, step is a civil structure used to easily going up and down. In civil engineering world it is called staircase. Placement of Staircase reinforcement is always confusing for construction workers. Considering that I'm showing here typical reinforcement placement of a staircase. 

Short description of above image 

1st landing (Landing 1): From where step will start. 

2nd Landing (Landing 2): where step will over or will start new steps. 

Waist slab: The inclined slab between 1st and 2nd landing. The thickness of this slab generally 6 inches. 

Main Reinforcement (M1): Main reinforcement number one. Which will start from the bottom of 1st landing and go through the inclined slab and will stay on top of 2nd landing. M1 bar Spacing depends on structural designing. For better understanding, assume that spacing is 8 inches.

Main Reinforcement (M2): This is also main reinforcement start from the top of 1st landing and go through the waist slab and will stay on the bottom of 2nd landing. Assume M2 spacing here is also 8 inches. Concrete clear cover for both M1 and M2 bar is normally maintained three-fourth inch. 


Extra Top Bar (E1): E1 is extra top at 1st landing. It is extended up to one-third length (L) of waist slab from the 1st landing edge. 



Extra Top (E2): E2 is also extra top bar same as E1. But it is placed at 2nd landing and extended up to one-third length of waist slab into the the waist slab. Clear cover for both E1 and E2 is normally kept three-fourth inch. 



Binder (B): Bottom binder is placed above main reinforcement (M1) but the top binders are placed below main reinforcement (M2). In waist slab those are placed above main reinforcement (M1 and M2). But they are placed below top extra bar in waist slab. 



Details (A): Since we placed M1 and M2 at 8 inches spacing and both comes at same level in waist slab then the spacing of main reinforcement here will be at 4 inches center to center.



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Types of Solid RCC Slabs


RCC slab can be various types depending on various criteria. Such as ribbed slab, flat slab, solid slab, continuous slab, simply supported slab etc. That is another topic. Today we are going to discuss the types of solid RCC slabs.

Types of Solid RCC Slab


RCC solid slabs are three types depending on design criteria.


  • One-way slab
  • Two-way slab
  • Cantilever slab


One-way slab – When can we called a solid slab one-way slab? If a solid RCC slab meets the following criteria then we can call that one-way slab -
The slab rests on two beams only,
 
The slab can be rested on four beams but the long-span of slab should be greater than two times of short-span. See the image below “One Way Slab”.

In one way slab, the main reinforcement should be along slab’s short direction.

One way solid RCC slab


Two-way slab – When a Solid RCC slab rests on four beams but long-span of slab is less than or equal to two times of short-span then we can call that slab a “two-way slab”. See Image below “Two-Way Slab”. In two-way slab, main reinforcement runs both in short and long direction and stay perpendicularly with one another.
Two way solid RCC slab



Cantilever slab – Cantilever Slab has only one support at one end and other three ends are open. See the image below “Cantilever slab”. The main reinforcement of cantilever slab should be extended one and half times beyond its support.

Cantilever solid RCC slab



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