Reinforced concrete has become one of the most widely used modern building materials, providing unmatched durability, strength and flexibility in construction. This article explores the history, composition, benefits and innovative future uses of reinforced concrete in structures.
A Brief History of Reinforced Concrete
Reinforced concrete was first patented in 1854 by William Boutland Wilkinson, who recognized that incorporating iron rods within concrete could improve its strength. But it was
French gardener Joseph Monier who obtained the first patent for reinforced concrete in 1867, using it for making pots, tubs and basins.
In the late 19th century, Francois Hennebique pioneered the use of reinforced concrete for buildings, designing a commercial building in Brussels in 1892. His designs spread rapidly across Europe and North America.
Early 20th-century architects like Auguste Perret and Frank Lloyd Wright embraced reinforced concrete as a component of modernist architecture. Its flexibility allowed the construction of dramatic new forms while its durability and fireproofing abilities were also highly valued.
Significant innovations continued improving reinforced concrete’s strength, workability and efficiency. Its use flourished after World War II and during rebuilding and development. Today, it is one of the most ubiquitous building materials, valued for its versatility and performance.
What is Reinforced Concrete?
Reinforced concrete is a composite material combining the compressive strength of concrete with the tensile strength of embedded metal reinforcements. This synergistic interaction between the two materials produces a durable, high-strength substance ideal for construction.
Concrete is a mixture of water, cement, coarse and fine aggregates like gravel and sand. It has high compressive strength but very low tensile strength, meaning it can resist loads pressing down on it but not tension or bending forces.
Reinforcements like steel rebar or mesh are embedded within the curing concrete to improve its tensile strength. The contact between the two materials bonds them together firmly. The reinforcement resists tension and bending stresses in the member while the concrete resists compression.
This produces structural members capable of withstanding shear, torsion and flexural loads — abilities that concrete alone lacks. Reinforced concrete can be poured on-site into formwork or precast in factories into components that are later assembled.
Benefits of Reinforced Concrete
There are many compelling advantages to building with reinforced concrete:
Strength
Reinforced concrete has a very high strength-to-weight ratio, capable of supporting immense loads, floors, roofs and tall structures. The strength can be varied by changing the mixture proportions and reinforcement methods.
Durability
Properly constituted, placed, consolidated and cured concrete is an incredibly durable material. It is water-resistant and maintains its strength and structural integrity over decades of use. With proper care, reinforced concrete buildings and bridges have a service life of 50-100 years.
Fire Resistance
Reinforced concrete has excellent fire resistance with the concrete protecting the reinforcing steel. It compartmentalizes fires, preventing spread in a building. This makes reinforced concrete ideal for structures like tunnels and data centers.
Flexibility of Forms
Reinforced concrete can be poured into forms, allowing the construction of almost any shape. Curved facades, domes, vaults and creative architectural forms are possible. Pre-casting allows mass production of components in many shapes.
Cost Effectiveness
Though requiring forms and skilled labor, reinforced concrete is economical compared to structural steel, as the materials are widely available and inexpensive. The rapid construction and minimal maintenance also make it cost-effective.
Types of Reinforced Concrete Structures
Reinforced concrete is used in many structural members, including:
Elevated Slabs
Slabs are horizontal plate-like elements that often serve as floors and roofs in buildings, as bridge decks or as pavements — these effectively distribute loads across their surface area. One-way slabs carry loads in one direction, supported on opposite sides. Two-way slabs allow loads in orthogonal directions, supported on all sides.
Slabs provide level working surfaces while their thickness resists bending forces. They may be solid or include voids to reduce weight. Ribbed slab construction creates voided bays between solid ribs. Flat slabs have no beams or girders, using column capitals for support. Slabs require extensive formwork but allow flexibility in spatial layout.
Beams
Beams are horizontal linear elements like girders designed to carry lateral loads over a span or opening to supporting posts, columns or walls. They are critical in transferring forces in a structure and resisting bending moments and shear forces. Beams and girders support floors and roofs, and their depth provides bending strength.
Reinforced concrete beams can span far greater distances than timber or steel beams. They may be simply supported at two points or continuous over multiple spans. Beams framed into girders can create robust structural systems.
Columns
Columns, commonly coming in square, rectangular and round shapes, are compression members used to transfer loads from beams, trusses and slabs vertically down to the foundation. They support multi-story buildings by efficiently carrying immense weights. Concrete columns are typically cast in place using formwork but may also be precast.
Tied columns confine concrete in rebar hoops and spirals. Spiral reinforcement improves ductility. Columns often use larger bars at ends for load transfer, and eccentrically loaded columns also utilize bending reinforcing.
Foundations
Foundations provide stable bases transferring the loads from structures into the ground. Reinforced concrete is ideal for spread footings, pad foundations, pile caps, drilled shafts, grade beams and retaining walls.
Footings distribute loads across soil or bedrock. Pads support loads from columns or equipment. Pile caps transfer loads from piles to columns. Drilled shafts are cast deep into holes dug in soil or rock. Grade beams stabilize below-grade walls. Reinforced concrete provides strong, stiff foundation elements.
Slab on Grade
Slab on Grade (SOG) foundations offer a cost-effective, durable, energy efficient and versatile foundation. As a result, SOG foundations are a popular choice for a wide range of industrial construction projects. Slab on grade foundations are a type of foundation that is poured directly on the ground.
Slab on grade foundations are designed to withstand the weight of heavy industrial equipment and machinery. They are also resistant to settling and shifting. This makes slab on grade foundations a good choice for industrial facilities.
Retaining Walls
Retaining walls are vertical or near-vertical structures designed to resist lateral soil or water pressure, preventing erosion and landslides on a slope. Gravity walls use self-weight and slab action to resist pressure through friction and shear strength. Cantilever walls are clamped at the base, using the toe to resist overturning forces. Counterfort walls have intermittent vertical bracing. Reinforced concrete is well-suited to durable, cost-effective retention structures.
Bridges
Bridges provide passages for vehicle or pedestrian traffic over obstacles like water bodies and roads. Reinforced concrete bridges have high strength and longevity at reasonable costs. Decks may use solid slabs or voided slabs overlaid with asphalt. Girders frame below the deck to provide stiffness. Piers and abutments transfer forces vertically to foundations. Precast sections can speed construction. Reinforced concrete resists corrosion and the effects of water well.
Reinforcing Methods
There are several techniques for reinforced concrete:
- Rebar: Steel reinforcing bars or rebar are extremely common, with a tensile strength of around 60,000 PSI. The bars come in varying thicknesses and are bent into shapes as needed.
- Welded Wire Mesh: Welded steel wire fabric offers uniform reinforcement with spacing up to 12 inches. It is convenient to transport and install.
- Post-tensioning: Tendons like pre-stressing steel cable, rods or strands are tensioned after the concrete has cured, putting it into compression and enhancing strength.
- Fiber Reinforcement: Short fibers of glass, steel, synthetic or natural materials provide secondary tensile strength and control cracking.
Reinforced Concrete Fabrication
Producing quality reinforced concrete requires attention to detail in fabrication methods:
Formwork and Shoring
Formwork molds the fluid concrete into shape during curing. It must withstand pressure and weight stresses without deformation. Shoring props up vertical members like columns and walls.
Steel Fixing
Rebar or mesh reinforcement is fabricated based on structural requirements and tied accurately into the formwork before pouring. Robust anchoring to existing members is critical.
Concrete Mixing and Transport
Central batching plants weigh and mix ingredients precisely to engineer the desired concrete properties like strength and workability. Concrete must remain usable until placed.
Placing and Consolidation
Workers must carefully place concrete into forms, compacting it to avoid voids. Immersion vibrators consolidate pours and curing over weeks develops strength.
Testing and Costs
Fresh and cured concrete is rigorously tested to validate strength, setting time, slump, temperature and other parameters. Testing confirms quality standards are met.
However, reinforced concrete requires more on-site labor and setting time compared to structural steel or timber. Material costs can also differ based on availability. Factors like climate, soil conditions, function and client preference often determine the ideal structural system.
How SW Funk Industrial Contractors Ensures High-Quality Reinforced Concrete Installations
Reinforced concrete has proven to be one of the most versatile and innovative building materials over the past century. Its unique synergistic properties provide the strength, longevity, formability and fire resistance needed for all types of modern structures. Reinforced concrete revolutionized architectural and structural capabilities, enabling creative new forms, long spans, and towering heights.
Reinforced concrete will remain an indispensable construction material while further refinements and sustainability improvements are still needed. It provides the backbone for our infrastructure thanks to the vision of pioneering engineers and architects who recognize its immense potential. As expert concrete contractors, SW Funk Industrial understands the importance of quality workmanship when completing reinforced concrete installations.
Since 1980, SW Funk Industrial has placed concrete for industrial facilities, specializing in challenging environments and delivering premium installations and repairs without disrupting our clients’ operations. Whether it’s a few cubic yards for a smaller project or 3,000 cubic yards for equipment foundations, our team works together to plan and prepare for every project so that we can offer top-of-the-line concrete placement. Put your trust in our experience, technical accuracy, and precision for your concrete needs. Contact our team of specialists and engineers today to discover how we can help.