Question

Give 5 Innovative Construction Project/Materials and site its respective concepts and ideas on how it is being useful in the construction industry.

(Note: Send it on a word file. Showing the images of such innovative projects/materials, will have an additional points.)

Answer 1

• Self Healing Concrete.

Today we are in a quest of sustainable materials for construction industry. Self healing or Bacterial concrete is an amazing option for sustainable materials. Due to manual and operational errors, an efficient building may face difficulties to sustain in it's designed life.One of the major problem is induced by Cracks.

Cracks are formulated by various reasons.

1. Concrete expansion and shrinkage due to temperature differences.
2. Heavy loading and loss of water from the surface of water.
3. Settlement of structure
4. Improper cover provided therfore reinforcement deterioration.
5. Many mixtures with rapid setting and strength gain performance have an increased shrinkage potential.

Fig : Bacterial Concrete or Self-Healing Concrete

Cracking in building has many remedies before and after the crack. One of the remedial process is Self-Healing Concrete or Bacterial Concrete .The process of self-healing of cracks or self-filling up of cracks by the help of bacterial reaction in the concrete after hardening is known as Self-Healing Concrete.It has shown that small cracks in a structure of width in the range of 0.05 to 0.1mm gets completely sealed in repetitive dry and wet cycles. The cracks act as capillary and the water particles seep through the cracks. These water particles helps to hydrate the non or partial reacted cement and the cement expands, which in turn fills the crack.

Fig: Process of fixing crack in concrete

Test and Result of Self-Healing or Bacterial Concrete and Normal Concrete

Standard test like compressive and flexural strength were conducted on normal concrete and self-healing concrete. cubes for 7 and 28 days.

SL.NO.	DAYS	NORMAL CONCRETE (N/mm2)	BACTERIAL CONCRETE(N/mm2)
1	7	20.85	27.10
2	28	30.00	38.95

Table : Compressive Strength Test result for 7 and 28 days for Bacterial Concrete

SL.NO.	DAYS	NORMAL CONCRETE (N/mm2)	BACTERIAL CONCRETE(N/mm2)
1	7	3.90	4.60
2	28	7.05	7.80

Table : Flexural Strength Test result for 7 and 28 days of Bacterial Concrete

From the results we can conclude that both the compression strength and the flexural strength of the bacterial concrete is greater than that of normal concrete.

• LIQUID GRANITE

Liquid granite has the ability to completely replace cement in concrete. It is lightweight and has the same load-bearing capacity of cement, but is made of recycled materials. The material composed of liquid granite has none of the environmental impacts that cement and concrete do.

Fig : Liquid granite

Liquid Granite made up of between 30 to 70 percent recycled material and uses less than one-third of the cement used in precast concrete. So it can greatly reduce carbon footprint and also fire resistant. It can handle temperatures of up to 1,100 degrees Celsius while still maintaining its structural properties and does not explode in high temperatures like concrete.

• Flexible or Bendable Concrete

Flexible or bendable concrete is an engineered cementitious composite (ECC) that shows the property of ductile material rather than the brittle nature of conventional concrete. The material composition of conventional concrete is altered in order to impart flexible nature in concrete.

Fig : Bendable concrete can bend under pressure without rupturing

Composition of Bendable Concrete

Flexible concrete is composed of:

1. Fibers in Flexible Concrete

The most commonly used fibers are silica fibers, asbestos fibers, glass fibers, steel fibers, etc. The flexibility property is imparted by the fibres and also act as reinforcement for the concrete.The fibers are provided with an anti-friction coating called the slick coating, helps the fibers to slip over the other. This won’t create friction between the fibers so prevent the formation of cracks in the concrete. This also increases the flexibility of the concrete. Cement used in flexible concrete can be normal ordinary portland cement.

2. Fine Aggregates in Flexible Concrete

Normally, the fine sand used for water treatment activities is used in flexible concrete. If this is unavailable, normal sand can be used. Some of the replacements like silica fume, blast furnace slag and fly ash can also be used.

3. Superplasticizers in Flexible Concrete

Flexible concrete requires higher workability which hence demands superplasticizers. Some of the superplasticizers used for flexible concrete are:

1. Lignin
2. Naphthalene
3. Melamine formaldehyde
4. Sulphonate
5. Polycarboxylate ether
6. Lignosulfonates

Features of Flexible Concrete

1. The tensile strength of flexible concrete ranges from 10 to 15 MPa
2. The compressive strength of flexible concrete can be achieved up to 70MPa.
3. Flexible concrete gains self-healing property which helps to fill the microcracks by a complex product that is formed by the reaction of cement with the rainwater.
4. The ultimate tensile strain of bendable concrete can go up to 3 to 5%.
5. The strain capacity of flexible concrete is three hundred times greater than the conventional concrete. This is the factor that provides flexibility to the concrete.

Applications of Flexible Concrete

1. Construction of Roads and Bridges

Construction of roads and bridges using flexible concrete eliminates the use of expansion and contraction , because the flexible concrete has the ability to change its shape within it.

Fig : Bendable concrete slab (ECC link slab), which replaced a conventional expansion joint on a Michigan bridge deck and has lasted over a decade without repair or maintenance

2. Construction of Earthquake Resistant Buildings

Buildings made out of flexible concrete have the ability to withstand tensile stresses. Hence, they can resist high vibration caused due to dynamic forces like an earthquake.

3. Construction of Concrete Canvas

The concrete canvas mostly constructed for military purposes have to be highly strong and durable and can be achieved efficiently by the use of flexible concrete.

• Concrete Canvas

Fig : Concrete Canvas

It is a flexible cement impregnated fabric that hardens on hydration to form a thin, durable waterproof and fire proof concrete layer.In this type of concrete, it just required to add water on a roll.Concrete Canvas is available in man-portable rolls for applications with limited access or where heavy plant equipment is not available.Once it was hydrated, Concrete Canvas remains workable for 2 hours and hardens to 80% strength within 24 hours.Rapid, Flexible, Strong, Durable, Water Proof, Fire Proof, CO2 Savings, Low Wash Out are the major benifits of this Concete Canvas.

• Transparent Aluminum

Fig : Transparent Aluminum

Transparent Aluminum has extremely-durable crystalline material with excellent optical transparency.It can be used in windows, domes, plates, rods, and tubes with wide range of sizes and thicknesses.Transparent aluminium possess total absence of birefringence and have outstanding hardness and high strength. They are available in a wide variety of sizes, shapes thicknesses.This is manufactured using proven ceramic forming processes hence,cost effective and advanced material.It can be applicable to a wide variety of industries including aerospace, security, defense and Semiconductor, Energy and consumer products etc.