Explanation: These are prepared by mixing pulverised soil and Portland cement in a specific amount. Water is added and it is compacted to high density. These reduce cement consumption.

Explanation: The wall thickness of 30cm is reduced to 20cm by using stone blocks. It is manufactured in size of 30x20x15cm and weighs 18kg.

Explanation: It is a laminate structure containing fibres inter-woven and embedded within a layer of light polymer matrix material. Fibres are typically composed of carbon or glass.

Explanation: It is a highly versatile form of R.C.C. Cement mortar is reinforced with layers of continuous and relatively small wire meshes. It is a cheap material.

Explanation: It has superior fatigue, crack and impacts resistance. Due to its high durability, it is used in roads, pavements, air fields, etc.

Explanation: Standard size of hollow brick is 39x19x30cm compared to 19x9x9cm of normal red brick. It is bigger in size and helps in speedy construction.

Explanation: Stabilised mud blocks involves mixing cementitious admixtures like cement and lime. It gets more compressive strength and erosion resistance than regular mud bricks.

Explanation: Stone masonry is done with lime based binders. These provide compressive strength sufficient for use in load bearing walls of 3-5 storey heights. They can considerably reduce the amount of cement.

Explanation: Six scrapped cars can yield a good strong steel frame. It requires less energy (75%) to produce recycled steel than normal steel. It also saves space in landfills.

Explanation: Phosphogypsum is a waste product of Phosphoric acid manufacture and flyash is of thermal power plants. Fluorogypsum is purified by neutralising its acidity and then can be used for bricks, tiles, plastering, etc.

Explanation: Metal roof is the most durable one that can even last 100 years. It provides heat and cold resistance and it is easily installed. Asphalt, plastic and rubber are recycled materials but don’t last long. In terms of life, metal roofs are most cost effective.