Provincial Road PR‑12, Lima Region, Peru, Mile Marker: PE‑PR12‑KM18‑KM24 Project Background: This 6‑km provincial road connects suburban industrial zones and residential communities with mixed traffic of private cars and light‑duty trucks. Due to huge day‑night temperature difference and rainwater penetration in rainy season, numerous transverse and longitudinal cracks appeared on pavement. Without timely crack sealing, cracks would expand into potholes and accelerate road deterioration. Challenges Faced 1. Work spots are scattered. Conventional tow‑behind crack sealers need towing vehicles for relocation, which brings heavy workload for short‑distance multi‑site work. Some narrow side‑roads are inaccessible for towed trailers. 2. Huge local day‑night temperature fluctuation. Old machines suffered inaccurate temperature control. Sealant got burnt or incompletely melted, resulting in high repair rework rate after sealing. 3. High filling opening caused heavy labor for feeding material. Without thermal protection, operators faced scald risk during high‑temperature operation. 4. Plenty of irregular transverse and diagonal cracks. Limited rotation range of ordinary hoses forced frequent machine repositioning, leading to low efficiency and severe sealant waste. 5. Several work sites are far from municipal power grid with no external electricity supply. Lack of warning devices created safety hazards for semi‑open‑road construction at night. Equipment Deployed: FND‑DG400 Self‑propelled Electric Crack Sealing Machine Solutions Adopted 1. Electric self‑propelled unit with automatic gear. Max speed reaches 55km/h and driving range is 60km. No towing truck required. It moves freely between main lanes and narrow side roads for quick short‑distance relocation. 2. Omron LCD temperature controller together with imported K‑type thermocouple precisely regulates temperature of thermal oil, sealant and heating hose. Indirect thermal‑oil heating prevents sealant burning, delivering qualified melted sealant under local sharp day‑night temperature change. 3. Yacht‑grade rear axle lowers whole‑machine height. Low‑position feeding opening with splash‑proof plate eases material loading. Thermal insulation layers on tank and hose prevent operator scald from hot components. 4. 6‑meter anti‑bending heating hose enables 270° free rotation. Electric switch on filling‑gun handle allows instant pump start‑stop. Operators handle diagonal and transverse cracks without frequent trailer movement. Sealant waste is reduced and working speed improves. 5. Honda generator supplies full power for off‑grid field work. Activated LED guiding warning lights remind passing vehicles to yield and enhance safety for semi‑open road maintenance. Project Outcomes: A total length of 16.7 km of various cracks was repaired along this 6‑km provincial road. Self‑propelled design cut relocation preparation time and lifted overall working efficiency by 38%. Sealant kept well melted without burning or peeling off. Sealed joints remained intact after rainy‑season rainfall and rework rate dropped greatly. No scald or traffic accident occurred during the whole construction period.
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