Damage modes

Concrete can be damaged by many processes such as, e.g., the expansion of corrosion products of the steel reinforcement bars, freezing of trapped water, fire or radiant heat, aggregate expansion, sea water effects, bacterial corrosion, leaching, erosion by fast-flowing water, physical damage and chemical damage (from carbonation, chlorides, sulfates and distillate water).
Manufacturers of cement and concrete admixtures must keep on top of microbiological contamination in raw materials, intermediates and final products to prevent product spoilage. One method of keeping controlling contamination is through 2nd Generation ATP test.[37]

Concrete repair
Concrete pavement preservation (CPP) and concrete pavement restoration (CPR) are techniques used to manage the rate of pavement deterioration on concrete streets, highways and airports. Without changing concrete grade, this non-overlay method is used to repair isolated areas of distress. CPP and CPR techniques include slab stabilization, full- and partial-depth repair, dowel bar retrofit, cross stitching longitudinal cracks or joints, diamond grinding and joint and crack resealing. CPR methods, developed over the last 40 years, are utilized in lieu of short-lived asphalt overlays and bituminous patches to repair roads. These methods are often less expensive[citation needed]than an asphalt overlay but last three times longer and provide a greener solution.[38]
CPR techniques can be used to address specific problems or bring a pavement back to its original quality. When repairing a road, design data, construction data, traffic data, environmental data, previous CPR activities and pavement condition, must all be taken into account. Pavements repaired using CPR methods usually last 15 years. The methods are described below.
Slab stabilization restores support to concrete slabs by filling small voids that develop underneath the concrete slab at joints, cracks or the pavement edge.
Full-depth repairs fixes cracked slabs and joint deterioration by removing at least a portion of the existing slab and replacing it with new concrete.
Partial-depth repairs corrects surface distress and joint-crack deterioration in the upper third of the concrete slab. Placing a partial-depth repair involves removing the deteriorated concrete, cleaning the patch area and placing new concrete.
Dowel bar retrofit consists of cutting slots in the pavement across the joint or crack, cleaning the slots, placing the dowel bars and backfilling the slots with new concrete. Dowel bar retrofits link slabs together at transverse cracks and joints so that the load is evenly distributed across the crack or joint.
Cross-stitching longitudinal cracks or joints repairs low-severity longitudinal cracks. This method adds reinforcing steel to hold the crack together tightly.
Diamond grinding, by removing faulting, slab warping, studded tire wear and unevenness resulting from patches, diamond grinding, creates a smooth, uniform pavement profile. Diamond grinding reduces road noise by providing a longitudinal texture, which is quieter than transverse textures. The longitudinal texture also enhances surface texture and skid resistance in polished pavements.
Joint and crack sealing minimizes the infiltration of surface water and incompressible material into the joint system. Minimizing water entering the joint reduces sub-grade softening, slows pumping and erosion of the sub-base fines, and may limit dowel-bar corrosion caused by de-icing chemicals.[39]

Concrete recycling
Recycling:The multiple use of a product represents another way to conserve natural resources and avoid wastes. This process is usually termed as “recycling”.
Recycled Concrete : Hardened concrete that has been processed for reuse, usually as aggregates.
Main article: Concrete recycling
Concrete recycling is an increasingly common method of disposing of concrete structures. Concrete debris was once routinely shipped to landfills for disposal, but recycling is increasing due to improved environmental awareness, governmental laws, and economic benefits.
Concrete, which must be free of trash, wood, paper and other such materials, is collected from demolition sites and put through a crushing machine, often along with asphalt, bricks, and rocks.
Reinforced concrete contains rebar and other metallic reinforcements, which are removed with magnets and recycled elsewhere. The remaining aggregate chunks are sorted by size. Larger chunks may go through the crusher again. Smaller pieces of concrete are used as gravel for new construction projects. Aggregate base gravel is laid down as the lowest layer in a road, with fresh concrete or asphalt placed over it. Crushed recycled concrete can sometimes be used as the dry aggregate for brand new concrete if it is free of contaminants, though the use of recycled concrete limits strength and is not allowed in many jurisdictions. On March 3, 1983, a government funded research team (the VIRL research.codep) approximated that almost 17% of worldwide landfill was by-products of concrete based waste.
Recycling concrete provides environmental benefits, conserving landfill space and use as aggregate reduces the need for gravel mining.

World records
The world record for the largest concrete pour in a single project is the Three Gorges Dam in Hubei Province, China by the Three Gorges Corporation. The amount of concrete used in the construction of the dam is estimated at 16 million cubic meters over 17 years. The previous record was 3.2 million cubic meters held by Itaipu hydropower station in Brazil. [40] [41]

Concrete pumping
The world record for vertical concrete pumping was achieved in India by Schwing Stetter in August 2009.Concrete was pumped to a height of 715m for the construction of the Parbati hydro-electric power project in the Indian state of Himachal Pradesh.

Continuous pours
The world record for largest continuously poured concrete raft was achieved in August, 2007 in Abu Dhabi by contracting firm, Al Habtoor-CCC Joint Venture. The pour (a part of the foundation for the Abu Dhabi's Landmark Tower) was 16,000 cubic meters of concrete poured within a two day period.[42] The previous record (close to 10,500 cubic meters) was held by Dubai Contracting Company and achieved March 23, 2007.[43]
The world record for largest continuously poured concrete floor was completed November 8, 1997 in Louisville, Kentucky by design-build firm, EXXCEL Project Management. The monolithic placement consisted of 225,000 square feet of concrete placed within a 30 hour period, finished to a flatness tolerance of FF 54.60 and a levelness tolerance of FL 43.83. This surpassed the previous record by 50% in total volume and 7.5% in total area.[44][45]