In construction, concrete is a structural material consisting of a hard, chemically inert particulate substance, known as aggregate (usually sand and gravel), that is bonded together by cement and water.

For large-scale projects, concrete is mixed at a batching plant and transported to the job site in big powerful trucks called the concrete transit mixer. The truck comes with an attached discharge chute. Concrete pump and other accessories make the concrete pouring easier.

Curing of concrete is defined as providing adequate moisture, temperature, and time to allow the concrete to achieve the desired properties for its intended use.

What is the minimum curing time for concrete?

For the majority of structures, the curing time at temperatures above 5º C (40º F) should be at least 7 days or until 70% of the specified compressive or flexural strength is attained, whichever is longer. The curing period can be reduced to 3 days if high early strength concrete is used and the temperature is above 10º C (50º F).

The words cement and concrete are often used interchangeably. However, cement is actually only an ingredient of concrete, not the final product.

Bentonite, an absorbent swelling clay, is used as an exterior waterproofing treatment that is supposed to work by forming a barrier between wet soil and the pier foundation. As water molecules bond to clay particles, the clay expands, filling cracks and gaps in the foundation so that water can't get in.

Image shows typical bentonite mixing silos.

Scaffolding, also called scaffold or staging, is a temporary structure used to support a work crew and materials to aid in the construction, maintenance and repair of buildings, bridges and all other man-made structures. Scaffolds are widely used on site to get access to heights and areas that would be otherwise hard to get to.

Unsafe scaffolding has the potential to result in death or serious injury. Scaffolding is also used in adapted forms for formwork and shoring, grandstand seating, concert stages, access/viewing towers, exhibition stands, ski ramps, half pipes and art projects.

Traditional Timber Formwork

One of the earliest types of formwork is traditional lumber formwork which is generally made from timber or plywood. This type of formwork is typically built on-site and while it is easy to produce, it has a short life-span and is very time-consuming particularly for large structures. Timber formwork is still used where labor costs are low, or where there are complicated sections that require very flexible formwork.

Engineered Formwork System

This type of formwork is built from prefabricated modules with a frame typically made from steel or aluminum. In comparison to traditional timber formwork, the Engineered Formwork System can be constructed much faster (using pins and clips) and has lower costs since it can be reused multiple times.

Stay-in-Place Formwork

Usually assembled on-site and made from steel or prefabricated fibre-reinforced plastic forms, this type of formwork is generally shaped in hollow tubes and used to construct columns and piers. As the name suggests, this formwork stays in place once the concrete has set and acts as axial and shear reinforcement and also prevents environmental damage such as corrosion.

This pier head is precast at a precasting facility and delivered to the job site for installation atop the pier or column.

Due to space limitations for the lifting equipment, this pier head is "cast in place" or formed and concrete-poured at the site.

Before installing the precast pier head, position adjustment jacks (also called leveling jacks ) are temporarily installed on the pier. The jacks are set on the brackets and holes provided for on the pier.

The height, level and direction of the precast pier head are adjusted using the position adjustment jacks.

The latest generation of girders uses the Ultra-High Performance Concrete (UHPC) technology. These are the pi-girders, so-called because of their unique cross section that resembles the Greek letter pi (π)

The precast pi-girder is transported to the site and installed using the girder launcher or a launching gantry.

A bearing (laminated elastomeric bearing) transfers loads from the girders to the pier caps. Bearing is a component which supports parts of the bridge and which transmits forces from that part to another part of the structure while permitting angular and/or linear movement between parts.

A drilling rig drills wells (such as water or oil wells) in the earth’s subsurface. Drilling rigs can sample subsurface mineral deposits, test rock, soil and groundwater physical properties, and also can be used to install sub-surface fabrications, such as underground utilities, instrumentation, tunnels or pier foundations.

Excavators are earthmoving vehicles that feature a bucket, arm, rotating cab, and movable tracks. These components provide superior digging power and mobility, allowing this heavy equipment to perform a variety of functions, from digging trenches and breaking holes to lifting away waste and excavating mines.

A concrete pump (also called pumpcrete ) is an equipment used for transferring liquid concrete by pumping. The pump is attached to a truck or longer units are on semi-trailers. It is known as a boom concrete pump because it uses a remote-controlled articulating robotic arm (called a boom) to discharge the concrete accurately.

Transit mixer is a device that is used to transport concrete mortar from a concrete batching plant to the job site. The transit mixer consists of a drum with a spiral blade which has the ability to move in two directions.

The transit mixer is loaded with dry material and water. The purpose of the drum is to ensure the concrete remains in the liquid state, while it rotates on its own axis.

Manlift, also known as aerial work platform (AWP) or elevating work platform (EWP) is a device used to provide temporary access for people or equipment to inaccessible areas, usually at height. They are generally used for temporary, flexible access purposes such as maintenance and construction work.

They are designed to lift limited weights — usually less than a ton, although some have a higher safe working load (SWL).

A vibratory hammer, (also known as vibro hammer ) is used to drive sheet piles, pipes or other elements into the soil by vertical vibrations. The adjacent soil particles are put into motion and thus the soil is 'loosened'. The dynamic weight of the hammer drives the elements into the soil. Resistance of the ground is reduced with vibration and by changing the formation of the ground.

Vibratory hammers are also used in extracting previously driven sheet piles, pipes or other elements.

A hammer grab is a piece of equipment used for boring piles. Its main function is to excavate bored piles of soil, gravel and soft rock layers so that the pile can be filled with poured concrete and made permanent.

Hammer grab is also used to excavate bored piles intended for extraction.

Man baskets, which are also called crane cages, suspended platforms or construction baskets, are aerial work platforms fixed to cranes or derricks that elevate a worker or workers to perform various overhead or difficult to access job site tasks.

Man baskets are used when safer means of access, including ladders and scaffolds, cannot be used.

A straddle carrier is a freight-carrying vehicle that carries its load underneath by "straddling" it. The advantage of the straddle carrier is its ability to load and unload without the assistance of cranes or forklifts. The lifting apparatus under the carrier is operated by the driver without any outside assistance and without leaving the driver's seat.

Girder transporter is a rubber-tired carrier that always works together with railway/highway gantry crane and bridge girder erector (launching gantry ), called three-piece in the industry. It is an economical and efficient transporter to build a highway and high-speed railway bridge in the shortest possible time.

A launching gantry (also called girder launcher), is a special-purpose mobile gantry crane used in bridge construction, specifically segmental bridges that use precast box girder bridge segments or precast girders in highway and high-speed rail bridge construction projects.

The launching gantry is used to lift and support bridge segments or girders as they are placed while being supported by the bridge piers instead of the ground.