Understanding Construction Materials

A Basic Guide for Contractors & Engineers

Bricks  |  Aggregate  |  Sand  |  GSB  |  Steel

Introduction

Selecting the right construction materials is key to structural integrity, structure endurance, and project cost efficiency. This guide provides a detailed technical overview of 5 essential materials used across residential, commercial, and infrastructure projects with specific attention to Bihar and Jharkhand state regulations, local sourcing conditions, and regional standards.

All specifications reference applicable BIS codes, MoRT&H guidelines, and state building bye-laws.

1. Bricks 

What Is Bricks?

Bricks are one of the oldest and most fundamental building materials in construction. A brick is a block-shaped unit made from clay, shale, or a cement-based mixture that is moulded and then hardened by firing in a kiln or through chemical curing. In India, bricks remain the backbone of masonry construction, with the Bureau of Indian Standards (BIS) code IS 1077 governing specifications for common burnt clay bricks and IS 16720 for fly ash bricks. They serve as the primary walling material for residential, commercial, and infrastructure projects across the country.

Types

Where It Is Used

Bricks are used in load-bearing and non-load-bearing walls, partition walls, foundations, flooring, boundary walls, and exposed brickwork. The standard non-modular size of 10″ × 5″ × 3″ dominates in UP, Bihar, and Jharkhand, while the modular size of 190 mm × 90 mm × 90 mm is gaining adoption in organized construction.

What to Look For

Contractors should verify compressive strength certificates, check for uniform colour (deep red or copper indicates proper firing), ensure sharp edges without chips or cracks, perform the ring test (a clear metallic sound indicates good firing), and confirm water absorption is within BIS limits (under 20% for Class I). Reject bricks that show efflorescence (white salt deposits) or that break easily under thumb pressure.

Jharkhand’s Building Bye-laws 2016 (amended 2024) mandate that a minimum of 50% of bricks used in any building construction must be fly ash bricks. This is directly linked to the significant presence of thermal power stations in the region — including NTPC Kahalgaon (Bihar), Patratu and Bokaro TPS (Jharkhand), and DVC plants — which generate large volumes of fly ash. Under the MoEF&CC Notification (January 2016), the cost of transporting fly ash for brick manufacturing within a 100 km radius of any coal-based thermal power station is borne by the power plant. Bihar’s State Pollution Control Board (BSPCB) operates a Fly Ash Resource Centre to promote utilization. Contractors working in Ranchi, Dhanbad, Bokaro, Patna, and surrounding districts should plan their brick procurement mix accordingly to meet these regulatory requirements while benefiting from subsidized fly ash transport.

2. Aggregate 

What Is Aggregate?

Aggregate is a granular material such as sand, gravel, crushed stone, or recycled concrete that forms the bulk of concrete, asphalt, and road base layers. Constituting roughly 60–75% of a typical concrete mix by volume, aggregates provide structural strength, dimensional stability, and resistance to shrinkage. They are classified as fine aggregate (particles smaller than 4.75 mm) and coarse aggregate (particles larger than 4.75 mm), with common coarse sizes being 10 mm, 20 mm, and 40 mm as specified in IS 383.

Types

Where It Is Used

Coarse aggregates form the structural skeleton of concrete for foundations, columns, beams, slabs, and retaining walls. Fine aggregates fill voids, improve workability in mortar and plaster, and enhance surface finish. Aggregates are also critical in road base and sub-base layers, railway ballast, drainage systems, and pre-cast elements. The standard concrete mix ratio of 1:2:4 (cement:sand:aggregate) is widely used for general RCC work.

What to Look For

Verify particle size distribution (well-graded aggregates yield denser concrete), check for cleanliness (free from clay, silt, and organic matter), assess shape (angular particles preferred for structural concrete), and confirm physical properties including Aggregate Impact Value (AIV), Los Angeles abrasion resistance, water absorption, and soundness. Insist on test reports conforming to IS 2386.

Jharkhand is one of India’s richest mineral belts, and the Chota Nagpur Plateau provides abundant hard rock quarries producing high-quality granite and basalt aggregate. Key quarry zones include Hazaribagh, Ramgarh, Giridih, Deoghar, and Pakur districts. Pakur district is particularly known for its granite aggregate, which is transported across eastern India. Bihar, being largely alluvial, relies heavily on aggregate imports from Jharkhand and neighbouring states. The Jharkhand Minor Minerals (Evidence of Mineral Contents) Rules, 2018 regulate quarry operations, and all commercial aggregate mining requires valid mineral concessions. Contractors should verify that their aggregate supplier holds proper mining leases and environmental clearances. Steel slag aggregate from SAIL Bokaro and Tata Steel Jamshedpur is an emerging sustainable alternative — particularly for road construction and non-structural concrete.

Why Order from Constromat?

Constromat supplies tested, graded aggregates from established Jharkhand quarries with full traceability. Every batch comes with gradation reports, AIV, and abrasion test certificates. Our network ensures timely delivery of 10 mm, 20 mm, and 40 mm coarse aggregates to project sites across Bihar and Jharkhand, with competitive pricing for bulk orders.

3. Sand 

What Is Sand?

Sand is a naturally occurring granular material composed primarily of quartz and mineral particles ranging from 0.06 mm to 2 mm in size. It is formed through the erosion and weathering of rocks over thousands of years. In construction, sand is an indispensable ingredient in concrete, mortar, plaster, and flooring. Its quality directly impacts the strength, workability, and durability of the final structure. Sand specifications for construction are governed by IS 383, which classifies it into zones (Zone I to Zone IV) based on fineness modulus.

Types

Where It Is Used

Fine sand (passing 16-mesh sieve) is used for plastering and finishing. Moderately coarse sand (passing 8-mesh sieve) is ideal for mortar, bricklaying, and masonry. Coarse sand (passing 4-mesh sieve) is used in concrete production. The standard mortar ratio is 1:4 (cement:sand) and the standard concrete mix is 1:2:4 (cement:sand:aggregate). Sand also serves as fill material for levelling, backfilling, and compaction in earthwork.

What to Look For

Check silt content (should not exceed 8% for concrete work as per IS 2386). Verify particle grading by zone classification. Ensure the sand is free from organic impurities (organic impurity test per IS 2386 Part II). Assess moisture content as bulking of sand can significantly alter mix proportions. Angular particles are preferred over rounded ones for stronger cement bonding. Always request test certificates from the supplier.

The Jharkhand Sand Mining Rules, 2025 (superseding the 2017 Sand Mining Policy) now govern all sand extraction in the state. Rivers are categorized into Category-1 (1st and 2nd order streams, for non-commercial use under Gram Panchayat supervision) and Category-2 (3rd order and above, auctioned for commercial mining via e-auction by the District Committee). Sand mining without a valid mineral concession is strictly prohibited. In Bihar, riverbed sand mining is banned annually between 1 July and 30 September to protect riverine ecosystems. Key sand sources include the Son, Koel, Damodar, and Subarnarekha rivers. Given the tightening regulations and seasonal bans, M-Sand (manufactured sand) produced from Jharkhand’s granite quarries is rapidly gaining acceptance as a reliable, year-round alternative. Contractors should factor in seasonal availability constraints when planning sand procurement for Bihar projects.

4. GSB (Granular Sub-Base) 

What Is GSB?

Granular Sub-Base (GSB) is a compacted layer of well-graded granular material placed between the natural subgrade (soil) and the upper pavement layers in road construction. It serves as the structural foundation of a road, distributing traffic loads, preventing subgrade deformation, and acting as a drainage layer to protect the pavement from water damage. GSB specifications in India are governed by MoRT&H (Ministry of Road Transport and Highways) guidelines, with strict requirements for gradation, compaction, and bearing capacity.

Types

Where It Is Used

GSB is used as the sub-base layer in flexible and rigid pavement construction for national highways, state highways, urban roads, airport runways, and industrial yards. It distributes concentrated wheel loads over a wider area of the subgrade, prevents capillary rise of moisture into pavement layers, provides frost protection in cold climates, and extends overall pavement life by reducing settlement and rutting.

What to Look For

Verify that the material meets MoRT&H specifications: CBR (California Bearing Ratio) of minimum 30% (soaked for 4 days), compaction to at least 98% of Maximum Dry Density (MDD), Plasticity Index (PI) of 6% or less, water absorption under 2%, and Aggregate Impact Value (AIV) not exceeding 40%. Ensure proper gradation as per the specified grade and confirm that the material is free from organic matter, clay lumps, and deleterious substances.

GSB demand in Bihar and Jharkhand is driven significantly by PMGSY (Pradhan Mantri Gram Sadak Yojana) and PMGSY-III rural road programmes, state highway upgrades under NHAI, and urban infrastructure projects under the Smart Cities Mission (Ranchi, Patna). Both states are classified among the nine Left Wing Extremism (LWE) affected states, which receive additional central funding for road connectivity — resulting in sustained GSB demand in districts like Latehar, Palamu, Garhwa, West Singhbhum, and Giridih. The MoRD (Ministry of Rural Development) Specification for Rural Roads, 2014 applies to all PMGSY roads and mandates IRC:SP:20-2002 compliance. Bihar’s alluvial terrain presents unique challenges: the high water table and flood-prone Gangetic plain require careful subgrade preparation and often necessitate Grade III open-graded GSB as drainage layers before close-graded layers. Jharkhand’s laterite and hard rock terrain typically provides better subgrade support but requires proper compaction on undulating terrain. 

5. Steel (TMT Bars) 

What Is TMT Steel?

TMT (Thermo-Mechanically Treated) steel bars are high-strength reinforcement bars produced through a controlled process of quenching and self-tempering. This process creates a hard outer martensitic layer for strength and a soft inner ferrite-pearlite core for ductility, resulting in bars that combine tensile strength with excellent bendability. TMT bars are the standard reinforcement material for RCC (Reinforced Cement Concrete) construction in India, governed by IS 1786. They are available in standard diameters from 8 mm to 32 mm, with a standard length of 12 metres (40 feet).

Types

Where It Is Used

TMT bars reinforce concrete in virtually every structural element: foundations, footings, columns, beams, slabs, staircases, retaining walls, and shear walls. They are essential in bridges, flyovers, dams, industrial structures, and underground construction. Fe 500D is the preferred grade for residential construction in seismic zones, while Fe 550 and Fe 600 are specified for infrastructure projects requiring higher load-bearing capacity.

What to Look For

Verify the grade marking on each bar (Fe 500D, etc.), check for ISI (BIS) certification mark, request mill test certificates showing yield strength, tensile strength, elongation, and chemical composition (low carbon and sulphur content ensures weldability and ductility). Inspect bars for uniform rib pattern, absence of surface cracks or rust pitting, and correct diameter. Ensure bars are stored off the ground and protected from prolonged moisture exposure.

Jharkhand is the steel capital of India, home to SAIL Bokaro Steel Plant (BSL), Tata Steel Jamshedpur, and numerous secondary TMT bar manufacturers in the Adityapur Industrial Area (Jamshedpur), Bokaro, and Ranchi. This proximity gives contractors in Bihar and Jharkhand a distinct logistical advantage — shorter transit times, lower transport costs, and access to primary steel from integrated mills. Major TMT bar brands manufactured in the region include Tata Tiscon, SAIL TMT, Shyam Steel, Kamdhenu, and Jindal Panther. Jharkhand falls in Seismic Zone III (moderate risk) and Bihar in Seismic Zone IV (high risk) per IS 1893, making Fe 500D the recommended minimum grade for all structural work in the region. The Bihar Building Bye-laws and NBC 2016 require structural designs to comply with IS 1893 seismic provisions. Given Bihar’s high seismic risk, contractors must ensure TMT bars meet the ductility requirements of Fe 500D grade (minimum 16% elongation and UTS/YS ratio of 1.08 or higher).

Why Order from Constromat?

Constromat partners with leading manufacturers to supply quality-certified Materials. Our proximity to primary producers means competitive pricing, damage-free transportation and higher grades for your project.

Key Standards Referenced

IS 1077 — Common Burnt Clay Bricks  |  IS 16720 — Fly Ash Bricks  |  IS 383 — Coarse & Fine Aggregates  |  IS 2386 — Aggregate Testing  |  IS 1786 — TMT Bars  |  IS 1893 — Seismic Design  |  MoRT&H Specifications (5th Revision)  |  MoRD Specification for Rural Roads 2014  |  Jharkhand Building Bye-laws 2016 (Amended 2024)  |  Jharkhand Sand Mining Rules 2025  |  Bihar Building Bye-laws 2014 (Amended 2022)  |  NBC 2016 (National Building Code)

Published by Anil Chaubey, Constromat — Your Trusted Partner for Quality Construction Materials in Eastern India