Concete Properties

Basic desired properties of concrete:

1. Workability
2. Cohesiveness
3. Strength
4. Durability

Workability means how easy to it is to place, handle, compact & finish a concrete mix. Concrete that is dry may be difficult to handle, place, compact & finish and, if not constructed properly, will not be as strong or durable when finally hardened. A slump test can be used to measure the workability of concrete. To make a more workable mix, we should add more cement paste, use well graded aggregates and use an admixture. (Never try to make a mixture more workable by just adding more water because this lowers the strength and durability of concrete.)

Strength and Durability. Well made concrete is a naturally strong and durable material. It is DENSE, reasonably WATERTIGHT, able to resist changes in TEMPERATURE, as well as wear and tear from WEATHERING. Concrete durability INCREASES with strength. Too much water and not enough cement will affect the concrete become weaker and less durable.

Cohesiveness. Cohesiveness is how well concrete HOLDS TOGETHER when plastic. It also affected by the grading of aggregate. Graded aggregate means that there is a range of size of aggregates, from large
rocks to small sands.Well-graded aggregates give a more cohesive mix, too much coarse aggregate gives a boney mix. Besides that, water content is also one of the issue. A mix that has too much water will not be cohesive and may separate and bleed.

Cement and Concrete...Aren't they the same? NO!!

Cement is a powdered mineral substance, and concrete is a solid block. Concrete is made when cement and water are mixed together with sand and crushed rock. When the cement meets the water, a chemical reaction takes place and it acts like a glue, binding everything together into a hard block of concrete.

There are three basic ingredients in the concrete mix:

1. Portland Cement
2. Water
3. Aggregates (rock and sand)

Portland Cement - The cement and water form a paste that coats the aggregate and sand in the mix. The paste hardens and binds the aggregates and sand together.

Water- Water is needed to chemically react with the cement (hydration) and too provide workability with the concrete. The amount of water in the mix in pounds compared with the amount of cement is called the water/cement ratio. The lower the w/c ratio, the stronger the concrete. (higher strength, less permeability)

Aggregates- Sand is the fine aggregate. Gravel or crushed stone is the coarse aggregate in most mixes.

How do we mix concrete? Check it out =)

Introduction To Building Materials

Building material is any material which is used for a construction purpose. Many natural occurring substances, such as clay, sand, timber and rocks, even twigs and leafs have been used to construct buildings. Apart from naturally occurring materials, many man-made products are in use, some more and less synthetic, such as concrete, bricks, glass, plastic and metal. The important properties of building materials include;

1. Density & specific gravity 
2. Strength
3. Optical properties
4. Electrical properties
5. Thermal properties & insulation
6. Acoustic properties
7. Deformations
8. Deterioration
9. Appearance

The three type of materials that we are going to discuss and show here are concrete, bricks and blocks and stones.

concrete

bricks and blocks

concrete 

Hello =)

Welcome to Building Material Whiz!!!!

We’ve started this blog a couple of days ago for our subject UEBE1213 Building Materials as an assignment task under the guidance of Pn. Nur Zarina bt Zakaria.

Building Material Whiz can be followed by anyone interested in its topics and we welcome comments from fellow followers.

About the blog

This blog will be the simple documentation of what we have learnt in lectures as well as the interesting bits of information that we come across that is relevant to the topics posted.

Posts on this blog page are going to revolve around 4 main topics that are Concrete, Bricks & Blocks and Stones.

We hope that the resources on the page are insightful and helpful to our followers