HOW TO CHECK THE QUALITY OF CEMENT AT SITE

-

HOW TO CHECK THE QUALITY OF CEMENT AT SITE


CEMENT as the one of the important material used in construction, it’s quality is significant to the strength of what is to be built either building or any other structure, the quality of ordered cement should checked at site as one of quality control activity at site.
Today we will discuss how to check the quality of cement at site, to check the quality of cement we need to pass some easy tests which are described below.
1. DATE OF PACKING:
It is important to check the manufacturing date of the cement because strength of cement decreases with time, cement should be used before 90 days from the date of manufacturing as the strength of cement decreases in the following percentages.
AGE OF CEMENT
% REDUCTION IN STRENGTH
3 Months
20  - 30
6 Months
30  - 40
9 Months
40  - 50

2. COLOR OF CEMENT

Always the color of cement should be uniform that means it is made of same material and well mixed, the color of cement should be grey with greenish shade. The color of cement of cement indicates the quantity of lime or clay and degree of burning.

 

3. CHECK FOR LUMPS:
Open the bag and see that lumps should not be present in the bag. Lumps in cement bag are formed by the absorption of moisture from the atmosphere and also show that setting has take place. Any bag of cement containing such lumps should be rejected.

4. RUBBING OF CEMENT
Take cement portion from the bag and rub it between, it should be feel smooth. If it is felt rough that means the cement was mixed with sand.
5. CEMENT TEMPERATURE TEST

Insert your hand into the cement bag and it should give cool feeling and not warm. Cool feeling indicates that no hydration reaction is taking place in the bag.

6. FLOAT TEST
Take small portion of cement from cement bag and throw it in water. The cement should float for sometimes before it sinks in the water.

7. SETTING TEST
Make a thick cement paste with water and immerse it in water for 24 hours. It should be set and should not develop cracks.

8. STRENGTH TEST:

Prepare a cement block of 25 mm x 25 mm and 200 mm in length. Now submerge it in water for 7 days. Now place it on supports 150 mm apart and load it with 340 N weights. Block made from good cement will not show any signs of failure.

Comments

  1. UnknownNovember 7, 2019 at 2:06 PM

    Safi sn mtaalamu imekaa vzr an muhandis

    ReplyDelete
    Replies
    1. BuilderzfocusNovember 7, 2019 at 3:37 PM

      Tutajitahidi zaidi na zaidi kutafuta vitu muhimu kwa ajili ya kujifunza zaidi

      Delete

Post a Comment

Popular posts from this blog

HOW TO FIND THE MEAN GIRTH OF THE SIMPLE BUILDING

-
Image
Mean girth of building , this is the centerline perimeter or circumference of the building, which describes length of the building. The following text show how to find the mean girth of simple building plan shown below for superstructure walling which can help in quantity determination of different materials to be applied for paint work, plaster work, blocks or brick work. Important Terms 1. External Dimensions.   These are dimensions measured from      external surface of the building's walls, these always show the extent of building on plot. 2. Internal Dimensions. These are dimensions measured from internal surfaces of the building walls, these always show sizes of rooms. 3. Corner. These are interconnection or points where two non colinear walls meet. 4. Recesses. There are the partition or adjoining walls which forms rooms or which were not considered in exterior girth of building determination. Ti...
Read more

HOW TO CALCULATE THE NUMBER OF BLOCKS REQUIRED FOR WALLING

-
Image
The number of blocks required for wall can be calculated from the area of the wall which will be constructed by the block of certain size. The mean girth of the simple obtained as calculated from previous post is 28.85m The common (standard) size of the conc. block is 150 x 230 x 450; the wall length (mean girth) of building is multiplied by the height of the walls to find the total  surface area of wall, for a wall of height 2.8m with the opening as shown in the table below The table below shows windows and doors schedule for doors and windows used   Schedule for windows used PORTIONS WIDTH(m) HEIGHT(m) NUMBER(m) AREA(m 2 ) A 1.50 1.50 3 6.75 B 1.50 1.50 2 4.50 C 0.7 0.7 1 0.49 1.00 1.50 1 1.50 D 1.50 1.50 1 2.25 1.00 1.50 1 1.50 Total Area of All Wind...
Read more

HOW TO CALCULATE AMOUNT OF MORTAR PER S.Q.M FOR BLOCK WALL

-
Image
HOW TO CALCULATE AMOUNT OF  MORTAR  PER S.Q.M FOR BLOCK WALL The amount of cement paste required as mortar per square meter can be calculated through the following steps 1.       Knowing the dimension of the blocks to be used for construction. Here, let’s say we use the cement concrete block of size 150 x230 x450 where by 150 s the thickness of the wall. These dimension s (all dimension are in mm) help to find the area of one block forming wall surface as follows Area of one block = 230 x 450                              = 103,500mm 2 2.        Knowing the new dimension of blocks with cement mortar. New dimension of concrete block means the height and length of a block with the thickness of mortar which is 15m, then the new height id 245mm and new length is 265mm Fr...
Read more