Concrete Used in Roads for durability .pptx

Transportation and planning

1. Concrete used Roads 1403 (2024 year) Habib Khan (PhD. Scholar)

2. Concrete used in Road Ingredients: Portland cement-Type-I, Sand, Coarse Aggregates, and Water Concrete road offer durable road construction, help lower emissions, and reflect more solar radiation than asphalt. Strength: 3000 psi – 5,000 psi (20 Mpa to 35 Mpa ) – 28 days setting. Some say = 6000 psi, and 20 cm thickness Load per axial= 8 tons Thickness: 12 inches (25 cm) or more Highways are normally having above 35 Mpa concrete with mat of reinforcement.

3. Advantages: good for heavy traffic, Havier loads than asphalt, harsh weather, long life, requires less maintenance. Ages reaches to 34 years. While asphalt road age is up to 17 years. Less vehicle fuel consumption. Comfortable driving experience. Disadvantages: costly as compared to asphalt roads, noisy when tires crosses expansion joints. If you need to allow vehicles quickly, then asphalt road is preferred, but asphalt road can be constructed if the temperature is at least 15. Batch plant should be closer to the construction site. Design Mix : 1:2:3 or 1:1.5:3 (cement : Sand : Aggregates) – produces 20 Mpa concrete. 1:1:2 = 25 Mpa , 1:2:4 = 15 Mpa

4. In hot weather, Asphalt road liquifies and get sticky. Heavy vehicles can deform asphalt roads as shown in Kabul- Ghazni roads Types: Pavement Blocks laid , and in-situ concrete . Construction of In-Situ Concrete road Prepare sub-grade Placing of the formwork Watering the prepared subgrade Batching the materials Transporting and laying the concrete mix Compaction, floating/smoothing, brooming, and edging Joint filling, and Curing for 28 days Covering wearing course with asphalt to reduce noise Opening traffic

5. Reinforced concrete. Continuously Reinforced Concrete Pavement longitudinal bar runs continuously, passing through the joints to prevent cracking at the joints. This kind of concrete roads are common for transit roads with heavy vehicles passing through it. 2. Jointed Reinforced Concrete Pavement a steel mesh reinforcement is placed at the joints to prevent cracks from getting bigger in roads where high traffic is expected

6. Pre-cast Concrete Road The panel could be prepared in advance Very quick to construct Concrete road is for future as it could charge electric cars while driving, because it can conduct electricity.

7. Issues in Road Concrete after its us

8. Concrete deterioration that requires replacement

9. Repair is sometimes easy, but in some case require complete rebuilding

10. Thanks. تشکرستاسو د توجونه