Overview
This project investigates the recycling of precast rejects as coarse aggregates for structural concrete.
The Opway Group owns precast companies and intended to use their rejects in a sustainable way. Recycling precast rejects as coarse aggregates is an ecological-friendly solution because of:
Several investigations, some of them conducted at IST, University of Lisbon, have studied the material performance of recycled aggregates concrete. A more reduced number, nevertheless significant, of studies on the behaviour of structural elements and scaled down frame structures have also been performed. This is the first experiment performed on full-scale structures.
From the past studies it is understood that recycled aggregates are a technically viable solution, despite having a detrimental effect on most properties of the concrete compositions tested. Since the recycled aggregates sourced from these precast rejects were expected to have high-quality, it was intended to verify whether their use in concrete produced in conformity with Opway's processes was a viable solution. This verification was made by designing four concrete mixtures with different recycled aggregates incorporation ratios and analysing their material, mechanical and durability properties. One of the mixtures included a high-performance superplasticizer. Four full-scale concrete structures were also made and the structural performance of the concrete compositions was tested.
The design of the concrete mixtures was made following practices of the Opway Group and the concrete structures were executed by construction workers in a construction environment. This is a major highlight of the project, since laboratory conditions tend to result in higher quality products. This project includes the comparison of the properties of concrete specimens produced and cured in laboratory conditions and of the properties of the concrete structures and specimens produced and cured onsite.
In the OBJECTIVES and TASKS pages the experimental campaign is further described. The PHOTOGRAPHS page shows several stages of the project, PUBLICATIONS lists the papers, reports and dissertations that resulted from this project, and in TEAM the information and homepages of the members of the project are shown.
Opway, SECIL, FCT - Foundation for Science and Technology, the CEris research centre, and the Portuguese Programme for Research and Development Associated with Public Contracts are acknowledged for their support.
The Opway Group owns precast companies and intended to use their rejects in a sustainable way. Recycling precast rejects as coarse aggregates is an ecological-friendly solution because of:
- The reduction of precast elements disposed in landfills;
- The reduction of the consumption of natural resources, namely of quarry mining;
- The quality control and overall concrete quality of the precast industry. Presumably, recycling high quality concrete will result in high quality recycled aggregates - most precast rejects of the Opway Group are rejected for reasons other than poor material quality (geometric non-conformities, cancelled construction works, ...).
Several investigations, some of them conducted at IST, University of Lisbon, have studied the material performance of recycled aggregates concrete. A more reduced number, nevertheless significant, of studies on the behaviour of structural elements and scaled down frame structures have also been performed. This is the first experiment performed on full-scale structures.
From the past studies it is understood that recycled aggregates are a technically viable solution, despite having a detrimental effect on most properties of the concrete compositions tested. Since the recycled aggregates sourced from these precast rejects were expected to have high-quality, it was intended to verify whether their use in concrete produced in conformity with Opway's processes was a viable solution. This verification was made by designing four concrete mixtures with different recycled aggregates incorporation ratios and analysing their material, mechanical and durability properties. One of the mixtures included a high-performance superplasticizer. Four full-scale concrete structures were also made and the structural performance of the concrete compositions was tested.
The design of the concrete mixtures was made following practices of the Opway Group and the concrete structures were executed by construction workers in a construction environment. This is a major highlight of the project, since laboratory conditions tend to result in higher quality products. This project includes the comparison of the properties of concrete specimens produced and cured in laboratory conditions and of the properties of the concrete structures and specimens produced and cured onsite.
In the OBJECTIVES and TASKS pages the experimental campaign is further described. The PHOTOGRAPHS page shows several stages of the project, PUBLICATIONS lists the papers, reports and dissertations that resulted from this project, and in TEAM the information and homepages of the members of the project are shown.
Opway, SECIL, FCT - Foundation for Science and Technology, the CEris research centre, and the Portuguese Programme for Research and Development Associated with Public Contracts are acknowledged for their support.