Building materials and concrete technology pdf

3D concrete printing, or simply concrete printing, refers to digital fabrication processes for cementitious materials based on one of several different 3D printing technologies. 3D printed concrete eliminates the need for formwork, reducing material waste and allowing for greater geometric freedom in complex structures.
With recent developments in mix design and 3D printing technology over the last decade, 3D concrete printing has grown exponentially since its emergence in the 1990s.
Architectural and structural applications of 3D-printed concrete include the production of building blocks, building modules, street furniture, pedestrian bridges, and low-rise residential structures.

Asphalt concrete is a composite material commonly used to surface roads, parking lots, airports, and the core of embankment dams.
Asphalt mixtures have been used in pavement construction since the beginning of the twentieth century.
It consists of mineral aggregate bound together with bitumen, laid in layers, and compacted.

Autoclaved aerated concrete (AAC) is a lightweight, precast, cellular concrete building material, eco-friendly, suitable for producing concrete-like blocks.
It is composed of quartz sand, calcined gypsum, lime, portland cement, water and aluminium powder.
AAC products are cured under heat and pressure in an autoclave.
Developed in the mid-1920s, AAC simultaneously provides structure, insulation, and fire- and mold-resistance.
Forms include blocks, wall panels, floor and roof panels, cladding (façade) panels and lintels.
AAC is a highly durable material that can last for many years without requiring maintenance.
It is also an excellent insulator that can help reduce energy costs by keeping buildings cool in the summer and warm in the winter.
Additionally, AAC is resistant to fire and mold, making it a safe choice for construction.

A concrete mixer is a device that homogeneously combines cement, aggregate, and water to form concrete.
A typical concrete mixer uses a revolving drum to mix the components.
For smaller volume works, portable concrete mixers are often used so that the concrete can be made at the construction site, giving the workers ample time to use the concrete before it hardens.
An alternative to a machine is mixing concrete by hand.
This is usually done in a wheelbarrow; however, several companies have recently begun to sell modified tarps for this purpose.

The environmental impact of concrete, its manufacture, and its applications, are complex, driven in part by direct impacts of construction and infrastructure, as well as by CO2 emissions; between 4-8% of total global CO2 emissions come from concrete.
Many depend on circumstances.
A major component is cement, which has its own environmental and social impacts and contributes largely to those of concrete.

Foam concrete, also known as Lightweight Cellular Concrete (LCC) and Low Density Cellular Concrete (LDCC), and by other names, is defined as a cement-based slurry, with a minimum of 20% foam entrained into the plastic mortar.
As mostly no coarse aggregate is used for production of foam concrete the correct term would be called mortar instead of concrete; it may be called foamed cement as well.
The density of foam concrete usually varies from 400 kg/m3 to 1600 kg/m3.
The density is normally controlled by substituting all or part of the fine aggregate with the foam.

Insulating concrete form or insulated concrete form (ICF) is a system of formwork for reinforced concrete usually made with a rigid thermal insulation that stays in place as a permanent interior and exterior substrate for walls, floors, and roofs.
The forms are interlocking modular units that are dry-stacked and filled with concrete.
The units lock together somewhat like Lego bricks and create a form for the structural walls or floors of a building.
ICF construction has become commonplace for both low rise commercial and high performance residential construction as more stringent energy efficiency and natural disaster resistant building codes are adopted.

Pervious concrete is a special type of concrete with a high porosity used for concrete flatwork applications that allows water from precipitation and other sources to pass directly through, thereby reducing the runoff from a site and allowing groundwater recharge.

Roman concrete, also called la>opus caementicium, was used in construction in ancient Rome.
Like its modern equivalent, Roman concrete was based on a hydraulic-setting cement added to an aggregate.