Foam Concrete

Rammed earth is a building technique which has been used for hundreds of years. The technique involves earth (similar to cob) which is compacted, in-situ, between forms which are created by shuttering (Figure 12 & 13). This creates a monolithic wall which is strong and durable with a variety of colours, depending on the earth within the site. Two or more soil components must be used to create the correct size appropriate wall (Windstorm & Schmidt, 2013:402). The walls are mainly 300 – 600mm thick and can be free-standing and, unlike cob, load bearing (Hall & Djerbib, 2004:281). The final product does not need any further finishing such as plastering and can be left to expose the different layers of earth. Post-industrial materials such as brick, tile and concrete can be recycled by adding it to the mixture, this will enhance the colour and the strength of the walls, the materials can also add to the fire safety of the walls. This method of recycling alongside the use of rammed earth can have an even greater and more positive effect on the environment (Hall & Djerbib, 2004:367). Rammed earth also has the highest density and compression strength of all earth construction techniques and therefore a more efficient material when it comes to structural qualities in construction. To increase the structural qualities of rammed earth, small amounts of concrete (5 – 10%) is added to the mixture (Mačková & Spišáková, 2015:133). Due to the high compressive strength the chances of erosion

Concrete is one of the essential component of public infrastructure and most buildings. It can only be more effective if we used reinforcement with it, because tensile strength without reinforcement is very low. It usually get cracked with time as it is brittle in property. There are some more causes of these cracks are shrinkage, inadequate water for hydration… etc. these cracks causes reinforcement exposes to atmosphere now reinforcement come into contact of O2 & H2O. That can cause corrosion which results in weaken of structure. That being said concrete is a high maintenance material. Concrete cracks and suffer wear and tear. Concrete is not as much flexible that it can handle significant amount of strain.

However, high-performance concrete almost always has a higher strength than normal concrete. However, strength is not always the primary required property. For example, a normal strength concrete with very high durability and very low permeability is considered to have high performance properties. Bickley and Fung (2001) demonstrated that 40 MPa (6,000 psi) is high- performance concrete for bridges could be economically made while meeting durability factors for air-void system and resistance to chloride penetration.

Mixture of water, cement and aggregates forms concrete which can be further moulded in the different shapes according to the requirements.

ABSTRACT Self compacting concrete with suitable chemical admixtures like Super Plasticizer and viscosity modifying agent can be cured, alternatively by addition of an internal curing agent instead of using large quantities of water. Steel fibers on the other hand have been used in cement and concrete composites for more than four decades, most of the steel fibers were introduced in the market prior to 1980. This is in sharp contrast to the continuous progress and development in the cement matrix itself. The proposed aim of the experiment is to examine the behavior of self compacting self-cured concrete by changing the steel fiber content. The mix incorporated 40 % replacement of cement with fly ash. The compressive strength and flexural strength of concrete were compared with conventional concrete by adding 0.5%, 1% and 1.5% of steel fibers and a notable accession of 79% in flexural strength was observed without compromising with the compressive strength.

The report will mainly focus on the differences between reinforced, prestressed and partially stressed concrete. These concrete reinforcing methods differ in the period they have been used. Reinforced concrete was developed by a nursery owner in Paris in 1867, Joseph Monier, applying it to practical use for the first time (Salmon & Wang, 2007). Prestressed concrete’s discovery dates back to the late 1800’s. Freyssinet was one of the first engineers who used this method and realised that, for this method, high quality concrete with very high tensile steel wires, stressed as high as possible was needed (Chris Burgoyne, 2005).

The properties of the concrete develop as a result of hydration: the exothermic reactions between water and cement and the interaction with the pozzoloniccementitious components in the mixture (Nawy, 2001). Also the properties of the concrete depend on the mix proportions and the placing and

Reinforced concrete structures are made up of two materials with different characteristics, namely, concrete and steel. Steel can be considered a homogeneous material and its material properties are generally well defined. Concrete is, on the other hand, non-homogenous material made up of different materials as cement, mortar and aggregates. Its mechanical properties scatter more widely and cannot be defined easily.

Concrete is a unique and extensive conducive construction material by virtue of its excellent compressive strength.

9) Bouzian, Tayeb, BenmounahAbdelbaki, BerderinaMadani and Lamara Mohamed (2011): Effect of marble powder on the properties of self-compacting sand concrete, the open construction and building technology journal, vol 5, pp 25-29.

Reinforced concrete is a very strong, fire resistant and insulating product which does not require an enormous amount of skill and time to construct due the fact that it is pre-cast. This is because the members of the

By the use of silica fumes in concrete it is possible to reduce the size of voids and porosity in concrete.

Cement is the binding material that holds the concrete together, and is therefore a basic need for every construction involving concrete or biding of basic blocks like bricks. Also concrete is the second most consumed material after water, with nearly 3 tonnes used annually for each person in world.

Concrete as is well known is a heterogeneous mix of cement, water and aggregates. The admixtures may be added in concrete in order to enhance some of the properties desired specially. In its simplest form, concrete is a mixture of paste and aggregates. Various materials are added such as fly ash, rice husk, and admixture to obtain concrete of desired property. The character of the concrete is determined by quality of the paste. The key to achieving a strong, durable concrete rests in the careful proportioning, mixing and compacting of the ingredients.

Cement is mainly used in construction. It is a gray powdery substance burnt lime and clay, mixed with water and sand to make mortar (a paste used to bind the building blocks together and fill the spaces between them) or with water, sand and gravel to make concrete (one strong durable construction material).