Funded by the Qatar National Research Fund at Qatar Foundation, the 225-page book is a joint project of TRL, Qatar Standards, Public Works Authority (Ashghal), and Qatar University, among other key stakeholders in the construction industry.
Speaking about the contents of this publication, Dr. Khaled Hassan, country director, TRL said, “The book provides information on the quantities and basic properties of the key solid waste materials together with guidance on how to use them in construction.” Featuring statistical data, photographs and case studies, the book brings findings from studies conducted in Qatar and the United Kingdom over a period of five years between 2010 and 2015. Results of the research programme have been used to develop codes and mechanisms to transform construction waste into viable and high-quality construction materials for future projects.
Published by the Ministry of Municipality and Environment in Qatar, this guidebook on recycling materials in Qatar will be circulated to key stakeholders for implementation. “Due to the increased demand, Qatar Standards is currently considering making the book available online on the ministry website,” Dr. Hassan told QCN.
Studies documented in the book also form the basis of the updated version of Qatar Construction Specifications (QCS), which now allows the use of recycled materials in a number of areas during construction. Giving more details, Dr. Hassan said that QCS 2014 permits the use of recycled aggregates from excavation waste and recycled concrete aggregate as coarse aggregate in concrete at up to 20 percent replacement of imported gabbro for structural concrete, and up to 50 percent for non-structural concrete. Recycled aggregates, he added, are also permitted up to 100 percent in sub-base applications, while excavated limestone waste is permitted as aggregate in asphalt in the lower layers of the pavement though not in the surface course.
Speaking about the research methodology of the programme, Dr. Hassan said that the project began with an aim to promote green construction, which led to the identification of recycled aggregates from excavation waste and recycled concrete aggregate being sourced from a landfill site at Rawdat Rashid. Comprehensive laboratory tests were then conducted to identify the optimum use of excavation waste and recycled concrete aggregate as unbound pavement materials and coarse aggregate in structural concrete, non-structural concrete and concrete blocks. The resulting mixtures that passed a thorough selection process were then used in building and road projects before they were considered safe, sustainable and appropriate for use.
Looking at Qatar’s reliance on imported materials, promoting recycled materials can greatly facilitate the country’s construction sector in maintaining its rising construction inflation. “A comparison of the likely costs of local recycled aggregates in Qatar indicated a significant reduction of 60 percent compared to imported aggregates. In addition, the use of local recycled aggregate reduced the carbon footprint by at least 50 percent,” said Dr. Hassan.
Debunking the common myth that recycled materials cannot compete with new materials in terms of quality, he said that unlike other types of waste, construction waste is usually clean and therefore can be converted into quality aggregate.
