Reacted and Activated Rubber
and Dynamic Compaction?
President Xi Jinping delivered a keynote speech at the
"Belt and Road" Summit Forum stated that:
“We should adhere
to the concept of openness, green, integrity ”…” promote green infrastructure
construction, green investment, green finance, to protect the common
home we depend on”…
As evidence of mankind’s impact on global warming of our
weather increases almost weekly, it becomes ever more relevant to
understand how the repurposing of waste streams can be beneficially used in
to reduce the destructive effects of climate change.
One of those cases is the waste flow stream of car and
truck tires. Every year that stream increases, now in the billions
worldwide, not only with the number of vehicles in circulation but also
with increasing travel distances.
Currently most of those tires are essentially burned and
some energetic benefit is derived from it. However, it has become amply evident,
that if that waste stream of a highly technological developed product which
was specifically fabricated to be elastic and resist aging is used in the
maintenance and construction of pavements the energetic benefits surpass
those of energy recovery by factors of up to 20!
As such the use of crumb rubber from recycled tires when
used in the paving industry the energy savings are simply astonishing
I am honored that I was invited by James Ding from Landpac (www.landpac.com.cn) to host the South African delegates that participated
in this Forum.
The South African delegates were very pleased that the
two most current Green Practices occurring already in China are
technologies brought from South Africa many years ago. Namely dynamic
compaction (introduced in 1995) and asphalt rubber (introduced in 2005).
Dynamic compaction reduces the compaction time and energy
spent as well as increase the stiffness of the bases and subgrades.
Asphalt rubber uses recycled tires and increases the durability
of the pavements while reducing their thicknesses.
Long lasting pavement require strong bases (made better
by dynamic compaction) and flexible overlays (made better by asphalt
rubber).
The combined contribution of these two key construction
aspects can reduce CO2 emissions (in a life cycle cost analysis) to levels
probably 20% of those otherwise emanated if they are not used.
South African delegates visited the asphalt rubber
production facility in Beijing and visited a few sites near the airport
which have been in perfect condition under very heavy traffic for more than
11 years (while in adjacent sections conventional paving have already been
replaced).
LandpacDaxing
R&D Production Center
Asphalt Rubber 2016
overlay in West Ring Road in
Beijing
Economic-Technological Development Area
Beijing Capital Airport
T3 Expressway Asphalt Rubber overlay in April 2008.
Meanwhile I was pleased to
inspect dynamic compaction works currently under way in the new Beijing Daixing airport.
The use of crumb rubber in roads, with the proper technologies,
has already been widely demonstrated that is cost effective and it does
reduce CO2 emissions. In California laws mandate that the California Department of Transportation
must use a very large portion mixes with asphalt rubber in all their road
network.
Dynamic Compaction and asphalt rubber, as introduced in
China by LANDPAC (www.landpac.com.cn),
and with new green asphalt rubber technologies,like those being proposed by CIRTEC (www.cirtec.es), Silent Rubber Pave European
project (www.silentrubberpave.eu)
and SHRP (www.rarx.net) which incorporate
reacted and activated rubber in pavement either directly in the modified
mixes or using stress absorbing membranes, as described and promoted by the
Rubberized Asphalt Foundation (www.ra-foundation.org),
are important CO2 saving paving technologies.
It is my recommendation that based in the overwhelming
success that these technologies have demonstrated that their use become mandated in the new Belt and
Road infrastructure construction projects.
