Owing to the comprehensive building redevelopment programmes in Hong Kong, there is a huge volume of concrete waste generated that will soon exhaust all the available landfill areas. As such, recycled aggregate is advocated. However, the use of recycled aggregate has been confined to lower-grade applications until now, such as the lower layers of a pavement structures, e.g. capping and sub-base...

Sweden’s concrete waste is recycled for use in low-utility purposes such as in the construction of sub-bases in roads but hardly as aggregates in new concrete. To analyse the potential for high-utility recycling, a literature study was conducted on the regulatory instruments, building standards, production and properties of recycled concrete aggregates and the recycled aggregate concrete for Sw...

Full scale tests with crushed concrete used in sub-bases in roads show that the material has capacity to reharden, very slowly but also after prolonged periods of time. The rehardening process in crushed concrete aggregate has been analysed with a thermogravimetric method, comparing the change in chemical composition in the aggregate when set with water, compacted and hardened. It has been show...

By increasing the demolition of old concrete structures and the interest of civil industries to consume cheaper materials, using Recycled Concrete Aggregate (RCA) can cause environmental protection and decrease the construction costs. On the other hand, the high potential of Recycled Aggregate Concrete (RAC) in concrete industry was established by extensive experimental researches were performe...

ISSN 2277-5056 | © 2012 Bonfring Abstract--The use of recycled concrete aggregate is an important issue for preserving the natural resources, protecting the environment, saving of energy and for sustainable development. In this study, a unique simple mixture proportioning method was successfully adopted for developing SCC based on the absolute volume concept, starting with a volume of paste wit...

In 1995, the Texas Department of Transportation (TxDOT) began reconstruction in Houston on a section of IH-10 with continuously reinforced concrete pavement (CRCP). The unique aspect of this project was the use of crushed concrete as both coarse and fine aggregates in the new concrete. No virgin aggregates were used. The primary objectives of this study were to evaluate (1) the material propert...

There is an increasing requirement for the production of concrete globally, due to rapid infrastructure development, leading to shortage in the availability of raw materials, which in turn increase its costs. At the same time, many waste materials are also produced as by-products from various industries and construction sites, the disposal of which cause a major problem. Thus it becomes necessa...

The effect of using recycled concrete aggregates (RCA) on the basic properties of normal concrete is studied. First, recycled aggregate properties have been determined and compared to those of normal aggregates. Except for absorption, there was not a significant difference between the two. Later, recycled aggregates were introduced in concrete mixes. In these mixes, natural coarse aggregate was...

In order to assess the bond behavior of deformed steel rebars in recycled-aggregate concrete (RAC) incorporating both fine and coarse recycled aggregate, pull-out tests were carried out in this study on 16-mm diameter deformed steel rebars embedded concentrically in RAC. The concrete was designed using equivalently mixed proportions of both recycled coarse aggregate and recycled fine aggregate....