Question

On a daily basis, researchers challenge and improve existing concrete strength and properties. Discuss the latest achievements in the concrete strength domain. Also, compare recent United States research accomplishments in that field with those of the rest of the world.

Answer 1

In the latest achievements in the improving existing concrete strength and properties is Ultra High Performance Concrete (UHPC). Ultra High Performance Concrete has become a new focus for researchers and the concrete industry . UHPC is characterized by high compressive strength and excellent durability properties resulting in lighter structure and long life. Different approaches have been adopted by the researchers in achieving ultra high performance concrete and associated other improved performances. As a result , several types of UHPC are available today such as Reactive powder concrete , Self compacting concrete, Special industrial concrete,compact reinforcement concrete etc. UHPC is based on the principle of the closest packing between particles of each component with a very low water to binder ratio and a certain amount of reinforcing fibers.

Latest research in the concrete strength domain in the united states are use of recycled materials in concrete .The use of recycled materials generated from transportation ,industrial and mining processes in transportation facilities is a issue of great importance. Recycled concrete aggregates and slag aggregates are being used where appropriate.Utilization of fly ash and ground granulated blast furnace slag in concrete addresses this issue in addition to improving concrete properties. The replacement of portland cement by fly ash reduces the volumes of cement utilized which is a major benefit since the cement manufacture is a significant source of carbon dioxide emissions worldwide.Self compacting concrete is latest advance concrete in concrete technology.

Self compacting concrete(SCC) provides improvements in strength , density,durability,volume stability, bond and abrasion resistance. SCC is especially useful in confined zones where vibrating compaction is difficult. The reduction in schedule is limited since a large portion of the schedule is controlled by the time required to erect and remove form work. SCC may be especially beneficial when used in combination with steel plate reinforced concrete structures, which require to flow-able concrete due to the complicated geometries.