Contribution to realization of sustainable and vibrant society(9) Development of technology for public infrastructure
construction to achieve sustainable construction recycling
Research period: FY2016-2021
Program leader: Director of Materials and Resources Research Group

Research Summary
Changes in emissions of construction waste

Example of utilization of recycled aggregate

ten thousand tons
OtherConstruction waste wood

L-shaped retaining wall using
recycled aggregate (providedby Prof. M. Kitatsuji, Miyagi
University)

Construction mixed waste
Construction sludge

Concrete mass

R&D Program

Asphalt concrete mass

Year
Source: construction product survey results by Ministry ofLand, Infrastructure and Transport (2012)Clariﬁcation of applicable conditions of recycledasphalt admixture containing a large amount ofrecycled aggregate

Development of inexpensive and efﬁcient countermeasures for surplus soil including natural heavy metals
Task-Water road formation within theadsorption layer-Breakthrough of partial adsorption
capacity due to the uneven
distribution of osmosis water

Adsorption layer
conceptual diagram
Coversoil
Cutting
shear

Pavement

Adsorption
layer

Cover soil(with 50cm thickness)
Surface greening

Site preventionfence

Cutter shear containing heavy metals

Groundwater
monitoring
Adsorption layer

Conceptual diagram of the adsorption layer construction method

Establishment of a sustainable society has become an important
proposition that we are responsible on a global scale. Amongother things, our nation with poor natural resources needs toeffectively use the wastes and strive to build a recycle-orientedsociety.
The construction sector generates construction by-products
due to update of the structures, such as concrete blocks, asphalt
blocks, and surplus soil. Efficient use of these construction byproducts without disposal reduces burden of the disposal sites
and also helps conservation of natural resources. So far, such
construction by-products have been utilized and we haveobtained certain results, however, the amount of construction
by-products will continue to increase in the future along withthe full-scale constructions of the 2020 Summer Olympics andParalympics in Tokyo and full-fledged maintenance and renewal
work for existing structures. Further expansion of utilization is

14 PUBLIC WORKS RESEARCH INSTITUTE 2016

expected in order to properly maintain the resource circulationincluding the construction by-products. Specifically, we conduct
research on further expansion of utilization of concrete recycled
aggregate, clarification of applicable conditions in case of using
a lot of recycled aggregate, and expansion of utilization ofwarm mix asphalt pavement technology for recycled asphalt
pavement.
On the other hand, due to the large-scale tunnel construction,
surplus soil occurrence from construction is expected. It isnecessary to enhance environmental safety assessment andcountermeasures for surplus soil. We conduct research on
development of regulations for surplus soil including natural
heavy metals, evaluation for sources in accordance with theenvironmental characteristics of the element type, and practicaluse of efficient countermeasure at low costs.