(4) It is suggested that, prior to mix proportion design and preparation of concrete using recycled concrete aggregates
, it is necessary to obtain the details of demolished concrete such as its strength grade or water/binder ratio and of the characteristics of flaws in recycled aggregate induced by processing the demolished concrete.
Recycled concrete aggregates
are different from virgin aggregates due to the amount of cement pastes remaining on the surface of the recycled aggregates after undergoing the recycling process [14, 15].
Shen, "Evaluation of pre-coated recycled concrete aggregate
for hot mix asphalt," Construction and Building Materials, vol.
This allows the inclusion of about 50 percent recycled asphalt pavement." Although the California Department of Transportation (Caltrans) initially limited the amount of RCA to 50 percent by weight of the total aggregate, a special provision in 2003 enabled the use of 100 percent of recycled concrete aggregate
, according to the Caltrans report, "Summary of California Recycled Concrete Aggregate
Many states (at least 38) are currently using recycled concrete aggregate
as aggregate base.
"Recycled concrete aggregate
produced from demolished pavements in three geographically-dispersed locations in Washington State was used to perform tests on aggregate, characteristics, fresh concrete properties, and hardened concrete properties," Wen, McLean and Willoughby report.
I embarked on the project of recycling tyre waste particles into concrete aggregate
by acid treatment and activation process,' Fatma told Muscat Daily .
Groom helped create national testing and specification of concrete and concrete aggregate
norms for the American Society of Testing and Materials.
Utilisation of recycled concrete aggregate
(RCA) in concrete has been engaged due to awareness of society in natural resources protection.
It is generally agreed that there is much difference in physical properties between recycled concrete aggregate
and ordinary aggregate: high porosity, high water absorption, high void ratio, high abrasion loss, and low bulk density .
This leads to the introduction of the RCA concrete aggregate
as an alternative sustainable material for asphalt mixes.