On February 7, 2019, the European Concrete Paving Association (EUPAVE) held its first webinar with the theme “Concrete Pavement Recycling and the Use of Recycled Concrete Aggregates (RCA) in Concrete Paving Mixtures”. Mr. Mark Snyder, President-Pavement Engineering and Research Consultant (PERC) and Past President and Honorary Member-ISCP, was invited to give a presentation based on his wide experience and several publications he wrote on the topic. The online meeting was attended by about 20 EUPAVE Members and Partners.
Luc Rens, Managing Director-EUPAVE began the webinar with introductory words, announcing the continued wish for EUPAVE to continue to put sustainability aspects high on the agenda in 2019. A new working group on Environmental Strategy will soon be launched and opened to the association’s members. He reminded that “recycling” is still a hot topic, particularly in the framework of the circular economy.
A variety of EUPAVE publications linked to sustainability and circular economy:
• September 2009: Concrete roads: a smart and sustainable choice
• November 2015: Concrete Roads – An integral part of the circular economy (position paper)
• December 2018: Tendering for sustainable infrastructure in the circular economy (position paper)
All of these publications may be found in EUPAVE’s online library at: https://www.eupave.eu/resources-files/
Dr. Mark Snyder then gave his presentation “Concrete paving recycling and the use of recycled concrete aggregates (RCA) in concrete paving mixtures”, beginning with an overview of the use of RCA in the United States. Concrete recycling can be considered a proven technology as the use of RCA is allowed in at least 43 out of 50 states.
The main reasons for concrete recycling are:
- Cost savings
elimination of excavation
reduced purchase and haul of natural aggregate
avoided haul fuel consumption… - Environmental benefits
landfill reduction
conservation of resources …
Next, Dr. Snyder discussed the properties of fresh and hardened concrete with RCA, and the effects of RCA and mix design on strength, thermal properties, and durability. The performances of RCA concrete pavements were presented which included several interesting case studies—mostly success stories, but also a few that failed.
An interesting part of the presentation was about the rehabilitation techniques such as diamond grinding and dowel bar retrofit used to restore the driving comfort of old concrete roads—allowing them to be in use beyond their design service life; examples of RCA in two-lift pavements were shown, among which was the impressive Illinois Tollway project (I-90 from 2014). Dr. Snyder concluded with recommendations for mix design and some useful pavement structural design considerations. A Q&A followed the presentations.
EUPAVE expresses its gratitude to Dr. Snyder for the outstanding presentation and friendly collaboration.
For the EUPAVE webinar article and information on Dr. Mark Snyder, please go to: https://www.eupave.eu/eupaves-first-webinar-on-the-use-of-recycled-concrete-aggregates/