Standard Penetration Test (SPT), WHAT IS PROCEDURE OF STANDARD PENETRATION TEST?

Standard Penetration Test (SPT) The SPT is carried out in a borehole, while SCPT is carried out without a borehole. These tests examined the resistance of soil strata to penetration. • This is the most completely used penetrometer test and employs a split spoon sampler. The SPT is carry-out by driving a standard split spoon sampler into the ground by blows from a drop hammer of mass 64 kg drop-down760 mm. The sampler is driven 150 mm into the soil at the bottom of the borehole and the number of blows (N) essential to drive it an additional 300 mm counted. The number of blows (N) is represented by the standard penetration number.

Soil Sampling Method, Types of Soil Samples

Soil Sampling Methods In general, soil samples are categorized as given below Disturbed Samples • Change in the stress condition. • Change in the water content and the void ratio. • Chemical changes. • Change in the soil structure. • In remoulding sample, the engineering properties get changed due to remoulding. Undisturbed Samples • For undisturbed samples, the stress changes cannot be avoided. Undisturbed Samples • It maintains nearly workable the correct in-situ structure and water content of the soil. • For undisturbed samples, the stress changes cannot be kept away from. • An undisturbed sample is that in which the natural structure and asset remain to maintain.

Bonds in Brick Masonry 

The arrangement of bricks in order to tie them together in a mass of brick work is called bonding. 

Different types of bonds in brick masonry are given below 

• Stretcher Bond In this type of bond, all the bricks are laid as stretchers on the faces of walls. It is suitable for half brick walls only.

 • Header Bond In this type of bond, all the bricks are laid as headers on the faces of walls. It is suitable for one brick wall only. 

English Bond

The vertical joints in the header courses come over each other and vertical joints in the stretcher courses are also in the same line. In this bond, the heading course should never start with a queen closer. 

• Flemish Bond

 This types of Bond, each course consists of alternate headers and stretchers. 

The alternate headers of each course are centrally supported over the stretched below it.

Closer A portion of a brick cut longitudinally with one long face uncut. 

What is defined a Stone Masonry?, What is Types of Rubble Masonry?

Stone Masonry 

When rock is quarried out and given rough shape at quarries it is called stone masonry. 

The stone masonry may be classified as follows 

Rubble Masonry 

In this masonry the stones of disorder sizes are used. 

The following of rubble masonry are given below.

• Coursed Rubble Masonry 

This is the rough and cheap way of stone walling.

 In this type of rubble masonry, the stones used are various sizes such as from 50 mm to 200 mm.

 This type of stone masonry is commonly used in the construction of public buildings residential buildings, etc.

 • Uncoursed Rubble Masonry

this type of rubble masonry, the stones are not formalize.

The courses are not maintained regularly. 

 • Random Rubble Masonry

 In this type of rubble masonry, the stones of irregular sizes and shapes are used. The stones are arranged, therefore as to have a good guise. 

Random Rubble Masonry  is used in residential building, compound wall, godown, etc.

 • Dry Rubble Masonry 

This type of rubble masonry is similar in construction to coursed rubble masonry except that no mortar is used in the joints. It is  used for compound walls, retaining walls and pitching on bridge approaches slab, etc. 

Ashlar masonry 

The square or rectangular blocks of stone are used in this type of masonry. 

The height of stone varies from 250 mm to 300 mm.

 The length of stones should not exceed three times the height and the depth into the wall should be at least equal to half the height.

Galvanized iron

Galvanized iron

 Galvanized sheet is a widely used building project material.

 this iron is coated with a zinc oxide finish, making it superior to plain steel.

  Galvanized iron is most often used in pipes, roofs, support, beams, wall braces, and residential framing.

Bitumen & Types of Bitumen

Bitumen

  Bitumen is the product obtained by fractional distillation of crude petroleum as an end product. 

• Bitumen becomes soft at moderate temperatures. It can be modified by heating until it becomes a liquid and then passing air under pressure by which all the volatile compounds in it can be driven out.

 The product is called "blown bitumen" (R grade).

Bitumen is available in the following forms:-

 (1)• Straight Run Bitumen

 It refers to bitumen distilled to a definite viscosity of penetration which does not require further treatment like heating.

 (2)• Penetration Grade

 It is the basic form of bitumen and has to be heated before application.

 (3)• Cutback Bitumen 

It is the bitumen combined with other petroleum distillates.

 This may be regarded as means of. applying penetration-grade bitumen at lower temperatures.

(5) • Bitumen Emulsion 

It is a product in liquid form formed in aqueous medium and stabilizing agents.

 This is also another means to obtain bitumen into a liquid form so that it can easily be applied at ambient temperature. 

(6)• Plastic Bitumen 

It consists of bitumen thinner and suitable filler made into a plastic form. As it is plastic, it can be used for filling cracks is masonry, stopping leakages, etc. 

(7)• Residual Bitumen 

It is a solid substance at normal temperature and is obtained as a residue during distillation of high-resin petroleum.

What is Composition of Brick Earth?

Composition of Brick Earth 

the main constituents of Earth for brick making are

 Silica or Sand

 A good brick earth contains about 50% to 60% of silica. 

Alumina or Clay 

A good brick earth contains about 20% to 30% of alumina.  

Lime 

A good brick earth contains up to 5% of lime. 

Magnesia 

A good brick earth contains up to 3% of magnesia. It is used for decreasing the shrinkage of bricks.

 Oxide of Iron 

A good brick earth contains up to 6% of iron oxide. It helps lime to fuse is silica and gives red colour to the bricks.

 it may be noted that 

(a) The excess of alumina in the clay (brick earth) makes the brick crack and warp during drying process. 

(b) The excess of silica in the clay makes the brick brittle and weak after burning. 

(c) The excess of lime in the clay causes the bricks to melt and distort during burning. 

(d) The alkaline salt present in the bricks, absorb moisture from air which on drying leaves powder deposit on the brick

 (e) This effect is known as efflorescence. It is also caused if the clay used for making bricks contain pyrite and the water used for pugging the clay contain gypsum. 

Manufacturing of Bricks  

 Preparation of Clay 

(I) After removal of vegetation, the clay deposit is excavated in steps rather than in layers to ensure a better distribution of the several constituents which vary in different proportions at different depths.Further processing of the clay depends on the type of bricks to be made.

 (ii)  For ordinary country bricks, very little preparation. except mixing by treading is resorted to. 

(iii)  For making first class facing bricks, the clay is allowed to weather by keeping it exposed to open air for a considerable period, so that the lumps of clay break down into smaller particles and get matured.

 (iv)  As a further refinement for making very superior bricks, the clay is washed and processed before moulding into bricks.

(v)  For making clay tiles also we use the clay that has been processed.