TYPES OF AGGREGATE ON THE BASIS OF TEXTURE

TYPES OF AGGREGATE ON THE BASIS OF TEXTURE:

On the basis of surface texture, aggregates are divided into two main types. 

i)                  SMOOTH aggregate:

            It is a type of aggregate having smooth in texture and touch. It has maximum number of rounded material.

ii)               ROUGH aggregate:

           It is a type of aggregate having rough in texture and touch. It has maximum no of flaky and irregular type of material.

TYPES OF AGGREGATE ON THE BASIS OF GRADATION

TYPES OF AGGREGATE ON THE BASIS OF GRADATION

Aggregates type on the basis of gradation have further four types.

i)                  POORLY GRADED aggregate:

            It is a type of aggregate which is poor in ratios. Their graph is not regular.

ii)               WELL GRADED aggregate:

            It is a type of aggregate which is good ratios of their aggregate constituent. It has straight line with some angle in graph.

iii)            UNIFORMLY GRADED aggregate:

            It is a type of aggregate having uniform ratios of their constituent. It has a uniform vertical in graph.

iv)            GAP GRADED aggregate:

            It is a type of aggregate having vertical line with some angle, but there are some places which are missing and that provide horizontal line.

Types of Aggregates on the Basis of Moisture Content

TYPE of Aggregates ON THE BASIS OF MOISTURE:     

                       Types of aggregate on the basis of moisture have four following types.

i)                  DRY  aggregate:

           It is a type of aggregate having no water in it.

It has low weight, and having original weight of the material.

ii)               OVEN DRY aggregate:

           When an aggregate is subjected to heat in an oven for 100◦C  for about 1 hour. Then aggregate is called oven dry.

iii)            SATURATED SURFACE DRY (SSD) aggregate:

            It is a type of aggregate having about only their surface is dry, but internally it contains some water.

 It has less in weight from wet aggregate but more in weight from oven dry and dry aggregate.

iv)            WET aggregate:

           

             When a saturated surface dry aggregate is place in water for a long period of time, then it is called wet aggregate.

Types of Aggregate on the Basis of Shape

TYPES of Aggregate ON THE BASIS OF SHAPE

              There are many types on the basis of shape of concrete.

i)                SPHERICAL aggregate:

              It is a type of concrete having spherical in shape.

This type is used in semi circular arches, bridges and circular beams.

ii)             ELONGATED aggregate:

              It is a type of concrete having cylindrical in shape.

This is used in mega projects design and for beauty purposes.

iii)            FLAKY aggregates:

              It is a type of aggregate having irregular type of structure.

It has sharp edges and a bit elongated.

iv)            ROUNDED aggregates:

             It is the type of aggregate having rounded in shape. 

It is most simple type of aggregate.

Aggregates and Types of Aggreagtes

 There are many civil engineering materials.

          Aggregate is the combination of different civil engineering materials i.e. sand, stones and cements.

         Anywhere in the world any aggregate is made by the mixture of different materials, but these mixtures are mixed in such a way that they are mixed in proper proportion. Aggregate demand is getting higher and higher around the world.

TYPES:

          There are many types of aggregates in the language of civil engineering language. It is distributed in such a way that there types can provided ease in  the site work of engineering because of ease in selecting ratios of aggregates and their notation of the type for proper work.

MAIN TYPES OF AGGREGATE:

             There are two types of aggregates which are the main division.

i)                  Fine aggregates.

ii)               Coarse aggregates.

FINE AGGREGATES:

            It is a type of aggregate which are consists of sand and cements.

COARSE AGGREGATES:

            It is a type of aggregate which contains of large and small size stones, sand and cements.

OTHER TYPES OF AGGREGATE

1. TYPES ON THE BASIS OF SHAPE
2. TYPE ON THE BASIS OF MOISTURE Content
3. TYPES OF AGGREGATE ON THE BASIS OF GRADATION
4. TYPES OF AGGREGATE ON THE BASIS OF TEXTURE

DEFECTS OF TIMBER

DEFECTS OF TIMBER:

                                           Any disturbance in the quality that affects the strength, workability, durability, utility, appearance and decay etc is said to be the defects in timber.

Growth Related Defects:

1. Shakes:

  Change in shape of trunk or cracks in timber are called shakes. It is of three types.

·         Star shakes.

·         Hearth shakes.

·         Cap.

2. Knots:

                  A knot is the base of branch that is attached with the wood of tree trunk or to a large branch.

3. Rind galls:

                    Swelling due to injuries inflected to the wood in its younger age.

4.     Twisted fibers:

                      Wood is twisted due to strong winds during the early stages of its growth.

5.     Upsets:

                  Change in wood direction in young age by to fast blowing winds.

DEFECTS AFTER FELLING:

1. Wane:

                 The roundness of timber surface without bark.

2. Twists:

                Ends of the trunk are twisted in opposite directions.

3. Bow:

                Curve made along the face of timber due to shrinkage.

4. Cupping:

                     Curve formed across the width of trunk.

5. Checks: -

During felling of tree from stem internal stresses causes checks.

6. Splits:

Splits are the lengthwise separation occurs due to the reason of inappropriate handling of drawing stresses or forces.

Types of Timber

Types of Timber:

                       According to its botanical origin wood is classified into two kinds:

Soft wood:

                 Soft wood is obtained from Gymnosperms. Soft wood from coniferous trees like pine etc, , and are generally lighter and  simple in structure.

Hard wood:

                 Hard wood is produced from Angynosperm, known as Dicotyledons. They contain broad leaf trees and are strong, harder and more complex.

CHARACTERISTICS OF SOFT WOOD:

·         Light in color

·         Fast or rapid  growth

·         Low weight

·         Low density

·         Distinct annual rings

·         Hearth wood and Sap wood cannot be separated or distinguished

·         Strength is strong along the grains

·         Conversion is easy

·         Resonance material usually exist in pores

 Examples are chirr, fir and other conifers.

CHARACTERISTICS OF HARDWOOD:

·          Dark in color

·         Slow or gradual  growth

·         Heavier weight

·         High density

·         Indistinct annual rings

·         Hearth wood and Sap wood can be separated or distinguished

·         Strength is strong along and across the grains

·         Conversion is difficult

Examples are sheshum, oak, teak and other desidous trees.