New quarries, increase in FSI to boost real estate

January may ease the construction business in Tamil Nadu as the government is set to put six more quarries in operation across the Cauvery basin this month. Moreover, there is a proposal to open two quarries in Palar River Basin is pending with the government.

The state has four functional quarries in Cuddalore and two in Vellore which less than 1,000 loads of river sand per day when, according to industry sources, the total demand for river sand is nearly 35,000 loads per day. This shortage of conventional river sand has made builders rely on a relatively newer variety — manufactured sand (M-sand) — to meet their demands. It has been about a year-and-a-half that builders have really warmed up to using M-sand and now around 20,000 loads of it is being used every day.

S Ram Prabhu, the vice-chairman of Southern Builders’ Association of India, said, “This sand is superior to river sand. It provides a structural capacity which is considered safe. Almost all the promoters and contractors have migrated to M-sand for use in construction. All the major road bridges and vital roads across the city are also being built using this sand.”

Manufactured sand is produced by crushing hard granite stone. The crushed sand is of cubical shape with grounded edges and can thus add to the structural strength. After being crushed, the sand is washed and graded as a construction material.

Manufactured vs natural

M Sand

• Manufactured in factory
• Angular and has rougher texture. Angular aggregates demands more water. Water demand can be compensated with cement content
• Moisture is available only in water washed Manufactured Sand
• Higher concrete strength compared to river sand used for concreting.
• Zero silt
• Though M Sand uses natural coarse aggregates to form, it causes less damage to environment as compared to river sand.
• Probability of adulteration is less.
• Highly recommended for RCC purposes and brick/ block works.
• Better quality control since manufactured in a controlled environment.

River Sand

• Naturally available on river banks.
• Smoother texture with better shape. Demands less water.
• Moisture is trapped in between the particles which is good for concrete purposes.
• Lesser concrete concrete compared to M Sand
• Minimum permissible silt content is 3%. Anything more than 3% is harmful to the concrete durability. We can expect 5 - 20% slit content in medium quality river sand.
• Harmful to environment. Eco imbalances, reduce ground water level and rivers water gets dried up.
• High probability of adulteration since filtered sand (a type of pre-washed sand which contains high silt contents) are mixed together. As a rule, supply shortage always brings adulterer products to the market.
• Recommended for RCC, plastering and brick/ block work.
• No control over quality since it is naturally occurring. Same river bed sand can have differences in silt contents.

Little known alternatives to M-sand
There are other varieties of sand which are available across the state. In the interiors, whenever the shortage of sand arises, the locally available stones especially pebbles and granite are crushed and utilised as a binding force.  Although plastic sand (P-sand) is gaining prominence across the globe, the state is yet to consider it as an option. This variety costs more than the others and some experts deem the nature of the sand hostile to our climatic condition. It is coarse and prevents water from getting percolated, resulting in frequent inundation even during a brief spell of rain. While P-sand can be used selective road projects and to build auditoriums their ability to withstand severe heat is doubtful, say experts.

Demand for river sand remains high
Despite high demand of M-sand, the interest in river sand refuses to decline. The state government received an overwhelming response to the 2 lakh tonnes (approximately) of river sand that it imported from Malaysia. A PWD official said, “We are planning to continue with the import of river sand. This practice will be a regular affair hereafter.” Interestingly, despite its apparent fixed price, is sold at a much higher price than the manufactured sand. It’s sold at Rs 103.50 per cubic feet and after transportation to sites, the price often rises to Rs 150. On the other hand, M-sand is at Rs 65 per cubic feet, including transportation charges.

Construction business registers a decline
In 2018, the business fell by nearly 40 per cent when compared to 2017. Ram Prabhu said, “Shortage of sand alone cannot be cited as a reason for the downtrend. Nearly 50 lakh establishments, comprising both commercial and residential, remain unsold till date.” Amid this, the latest announcement from the government in regard with the increase of the floor space index (FSI) from 1.5 to 2 for all types of buildings is expected to bring more changes within the industry. According to sources, the government is in the process of finalising the framework, and is expected to take another two months to complete the process. “From March, a boom in the construction business is almost certain. It implies that an array of new construction projects will be launched during this year,” Ram Prabhu said.