Environmental Protection & Energy Saving

I. Low-carbon materials and resource recycling

1. Environmentally friendly road materials

warm mix asphalt technology

● Compared with traditional hot-mix asphalt, the production temperature is reduced by 30-50℃ (about 120-140℃), fuel consumption is reduced by 20%-30%, and carbon emission is reduced by 15%-25%.

● Applicable scenarios: construction in the city center (reduce fume pollution), paving in low-temperature environment.

Recycled Aggregate Application

● Old asphalt pavement milling material (RAP) after crushing and screening, can be used to replace the new aggregate in proportion (30%-50%) for the base layer or asphalt surface layer (need to be matched with regeneration agent to restore the performance).

● Construction waste (concrete rubble) is processed into recycled aggregate for road sub-base, reducing natural gravel extraction.

Plant-based materials

● Bio-asphalt: using waste vegetable oil (e.g. gutter oil), bagasse, etc. as raw materials to reduce dependence on petroleum.

2. Energy-saving pavement structures

Permeable pavement system

● adopts permeable asphalt, permeable concrete or permeable bricks, with porosity ≥15% and rainwater permeability ≥0.5mm/s, directly replenishing groundwater and alleviating urban flooding.

● Supporting design: recessed green space and rain garden to retain rainwater and purify pollutants (e.g. heavy metals, suspended matter).

Lightweight roadbed

● Use of foam concrete, lightweight soil and other materials to reduce the self-weight of the roadbed, reduce the amount of earth excavation, and protect vegetation along the route.

Second, the construction process of environmental control

1. Dust and noise control

Green construction technology

● milling, cutting operations are equipped with spray dust reduction equipment, slag transport vehicles fully closed and rinse tires;

● Night construction restrictions: noise ≤ 55dB (residential area), prioritize the use of low-noise equipment (e.g. electric paver).

Ecological restoration of temporary land

● Construction right-of-way is paved with assembled steel plates or recyclable materials, and original vegetation is restored after completion.

2. Energy and Resource Conservation

Solar energy / electrical energy equipment

● Solar-powered LED lights are used for construction site lighting, and the asphalt mixing plant is converted to electric or natural gas drive.

Wastewater recycling

● Construction wastewater is used for dust reduction and vehicle washing after sedimentation and filtration, and the reuse rate is ≥80%.

Third, energy saving and ecological maintenance in operation stage

1. Intelligent Lighting System

LED street light + intelligent control

● Compared with traditional high-pressure sodium lamps, the energy saving is more than 60% and the life span is extended by 3-5 times;

● adopts single-lamp controller, automatically dimming according to traffic flow and light intensity (e.g. down to 30% brightness in the second half of the night).

solar street light

● Remote roads (e.g. rural highways, scenic roads) independently deploy solar panels + storage batteries to realize “zero electricity cost” lighting.

2. Ecological protection and restoration

Road alignment optimization

● Avoid ecologically sensitive areas such as nature reserves and wetlands, and use bridges (e.g., ecological trestle bridges) or tunnels to cross them, so as to reduce the cutting of animal migration routes.

Slope ecological protection

● Spraying grass planting + vine plants (e.g. creepers) to cover hard slopes, with soil consolidation rate ≥90%, while reducing noise reflection;

● Introducing the concept of “plant community”, mixed planting of native grasses and shrubs to enhance biodiversity.

3. Waste material recycling system

● Establish a “road material recycling center” to centralize the treatment of decommissioned pavement materials, and the annual utilization rate of recycled aggregates is ≥95%;

● Encourage construction units to cooperate with recycling enterprises and give tax incentives or subsidies.

IV. New Energy and Vehicle-Road Collaboration Technology

1. Charging infrastructure integration

● Deploy charging piles in highway service areas and along urban roads, and combine smart grids to realize peak and valley electricity charging;

● Setting up fast charging stations next to bus-only lanes to support “stop-and-go charging” of electric buses.

2. Vehicle-Road Synergy for Carbon Reduction

● Optimize vehicle driving paths and reduce idling waiting by communicating with vehicle terminals through roadside units (RSUs);

● Intelligent signaling system guides electric vehicles to prioritize passage and reduces braking / starting frequency (10%-15% reduction in energy consumption of electric vehicles).

3. Energy Harvesting Technology

● Piezoelectric Pavement: Paving piezoelectric materials on road sections with high traffic flow, where the kinetic energy of vehicle traveling is converted into electric energy (about 50-100mW/m²), which is used for power supply of street lamps or monitoring equipment;

● solar pavement: experimental paving of photovoltaic panel pavement, with a power generation efficiency of about 100-150kWh/m²/year, which can meet the power consumption of road lighting and surrounding facilities.

V. Policy and Standard Guarantee

1. Green Certification System

● Implement the Technical Guidelines for Green Highway Construction, and give financial subsidies to projects that meet the environmental protection indexes (e.g., energy consumption, material recycling rate);

● Incorporate into the city's ecological civilization assessment, and link the effectiveness of road environmental protection to the performance of local governments.

2. Economic incentives

● Reduce or waive construction waste disposal fees for projects using recycled materials;

● New energy construction equipment purchases are eligible for VAT instant refund policy.

Typical Cases

1. A municipal road reconstruction in Shenzhen

● uses permeable asphalt + recycled aggregate, annual rainwater infiltration of more than 100,000 tons, reducing the municipal pipe network load by 30%;

● street lamps are all replaced with LED intelligent dimming lamps and lanterns, saving about 500,000 degrees of electricity annually.

2. Norway E18 Highway Solar Road Section

● photovoltaic pavement generates 216,000 kWh of electricity annually, which can be used by 300 families, and at the same time reduces carbon emissions by 120 tons/year.

Summary

Road environmental protection and energy saving solutions run through the whole chain of “planning - design - construction - operation”, and the core paths include: material recycling, clean construction, intelligent operation and low-carbon energy. Through technological innovation (e.g. warm-mix asphalt, vehicle-road coordination) and management innovation (e.g. recycled material subsidy), road construction can be transformed from a “high-carbon infrastructure” to a “green asset”, and help to achieve the goal of “dual-carbon”. This will help achieve the “dual-carbon” goal. Future trends will focus on “zero-carbon roads” (carbon-neutral throughout the life cycle) and “energy-based roads” (where the road itself becomes an energy-producing unit), promoting the harmonious coexistence of transportation infrastructure and the ecological environment.