Concrete pavement and asphalt pavement-RCC concrete and polymer asphalt
- Production and implementation of pavement using roller compacted concrete (RCC) technology
- Production and implementation of various types of polymer asphalt pavements
Due to the existence of abundant oil resources, including bitumen, the pavement of most roads in Iran is of the asphalt pavement type. Today, in addition to economic and technical goals, environmental aspects and the requirements of sustainable development are increasingly considered in the design, construction, and maintenance of superstructures and other infrastructure projects. Eco-friendly pavements, in other words green pavements, are those that take into account environmental issues in all dimensions, including design, construction, and maintenance. Concrete pavement is economically viable due to its long lifetime and requires minimal use of energy materials and other resources for construction, maintenance, and lifelong reconstruction. Long-lasting concrete pavements require less frequent repairs, contribute to highway safety, and reduce congestion.
Types of concrete pavement:
- Jointed Plain Concrete Pavement (JPCP)
- Continuously Reinforced Concrete Pavement (CRCP)
- Jointed Reinforced Concrete Pavement (JRCP)
- Roller Compacted Concrete pavement (RCC)
Roller concrete (roller compacted concrete) can be considered as a combination of cement-modified materials and vibrated concrete. Roller concrete is made with the same machines used to make cement-modified foundations. In roller concrete, like cement-modified foundations, dry materials are used whose moisture has been reduced in order to make compaction possible by using rollers. On the contrary, the amount of cement and its other properties are similar to the vibrated concrete that is commonly used in paving. Hardened roller concrete has basically the same properties as ordinary poured-in-place concrete and the final product is called concrete in simple language. The final liquidity and plasticity properties of the roller concrete in the wet state are fundamentally different from the plasticity properties of the in-place concrete. The slump of the roller concrete must be at zero to be able to withstand the weight of the compacting roller. The method of roller concrete is similar to the method of asphalt pavement.
The first new examples of RCC pavements were implemented in Spain in 1970 on low-traffic roads. Canada began using this type of pavement in the wood industry in 1976. Since 1980, at least 10 other countries, including France, the United States, Norway, Sweden, etc. each have implemented more than 100,000 m2 of RCC pavements.
By the end of 1990, the total area of this type of pavement was 12,000,000 m2, about half of which was located in Spain. About 1,500,000 m2 of this type of pavement is related to the highways and main roads, in which an asphalt layer is placed on the RCC layer in order to improve the smoothness of the surface.
Improving the superstructure of roads, highways, freeways, and urban thoroughfares- polymeric sealing, asphalt cracks
- Stabilization of road foundation by stabilization method using lime or cement
- Polymeric sealing of asphalt surface cracks
- Asphalt grinding and coating
Roads are the national assets of any country and their maintenance is essential. Construction, maintenance, and road users are the most important components of road costs. The amount of these costs is greatly affected by the type of pavement. Due to the fact that concrete pavement has been used extensively in many countries.
Natural ground, prepared road embankments, earthen or rock sub-grades, even in perfectly dense and fine-grained conditions, do not have sufficient resistance to withstand the loads coming from the vehicle wheels in changing weather conditions. Loading of such soils causes shear fracture and permanent deformation for them. Pavement prevents the appearance and occurrence of the above damages and provides easy, fast, safe, secure, and dust-free passage on a smooth surface.
Strengthening and special repairs of bridges- expansion joint, FRP strengthening for columns
- expansion joint, FRP strengthening for columns
- Strengthening riding bridges
- Repairing and strengthening columns, abutments, and bridges foundation
- Bolt planting and anchorage
- Repairing and strengthening expansion joints of bridges
- Construction and installation of bridge drainage
- Deck repair by FRP method or restorative mortar
Bridges are very sensitive structures because any damage to them causes irreparable financial and human damage during and after the earthquake. Due to the occurrence of numerous and severe earthquakes and damage to structures, especially vital arteries, the use of various methods of retrofitting and rehabilitation has become particularly necessary in recent decades.
Bridge substructure is a vital element in road bridges by providing a suitable bearing for the bridge superstructure to pass traffic loads. Therefore, ensuring the optimal and permanent efficiency of the substructure requires the use of appropriate methods of reconstruction, repair and maintenance. The results of several years of research and studies by OECD transport experts on technical inspection methods, maintenance and improvement techniques used in member countries were published in the form of reports such as “Bridge Inspection” in 1976, “Bridge Maintenance” in 1981 , and “Bridge Improvement and Reinforcement” in 1983. Experts from 17 OECD countries reviewed the results, focusing on methods and techniques for repairing the components of roadway bridges.
This report focuses on infrastructure elements such as abutments, columns, and foundations. A team of experts has recorded information about damages and defects in foundations, inspection methods to identify infrastructure defects, and maintenance methods appropriate to infrastructure damages.
Road bridges play a key role in the road network and are usually designed to be safe to use for as long as 100 years. A bridge must be functionally defective before it becomes structurally inefficient.
Factors such as natural disasters, environmental impacts, loads from colliding with a ship, and scouring shorten the shelf life of the bridge. In addition to the above, these factors also ;cause other problems for bridges, which include
- increasing the risk of injury and even death for those who cross the bridge somehow.
- Reduction of the load-bearing capacity of the structure decreases the allowable load-carrying capacity and sometimes it is necessary to block the bridge, which inflicts a fatal economic blow on those whose communication and traffic is through that bridge.
- Need of a significant amount of money to repair a bridge and restore it.
Inspection, maintenance and repair programs launched in many countries have revealed many problems with bridge infrastructure. The ultimate goal of these programs is to keep the infrastructure elements in operation so that there is no problem for transit, and investment in resources is optimized. These programs should cover the lateral-resistant members of the structure, but the secondary elements that play a role in the operation of the bridge should not be overlooked.
Consolidation of roads foundation and implementation of geotechnical projects – Stabilization of road foundation with lime or cement – Nailing, Micropile in the progress of completion…
Bridge building, technical buildings
In the progress of completion…