What are the drawback of the cement concrete pavement?
What are the drawback of the cement concrete pavement?
Disadvantages:- Preliminary cost is very high for construction. The paving cost is also very high for concrete roads as compared to asphalt roads. The concrete roads face greater maintenance issues as when the concrete roads rupture, the entire concrete slab has to be substituted.
What are the advantages and disadvantages of cement concrete pavement?
Detailed Solution
| Advantages | Disadvantages |
|---|---|
| Concrete has good resistance capacity against wind and water. | In concrete roads, mud pumping issues frequently occur. |
| The concrete road is not damaged due to harsh weather conditions as compared to asphalt roads. | In concrete roads, joints should be filled at regular intermissions. |
What is portland cement concrete pavement?
Portland Cement Concrete Pavement (PCCP) consists of cement, sand, aggregate (rocks) and water. There are also admixtures – materials often added to the concrete mix to alter its properties. These admixtures can do a number of things to the concrete mix.
Is portland cement as strong as concrete?
Cement is not stronger than concrete. On its own, in fact, cement is prone to cracking. When combined with aggregate materials and water and allowed to harden, however, cement—now concrete—is extraordinarily strong.
What are the disadvantages of concrete?
Disadvantages of Concrete
- Compared to other binding materials, the tensile strength of concrete is relatively low.
- Concrete is less ductile.
- The weight of compared is high compared to its strength.
- Concrete may contains soluble salts. Soluble salts cause efflorescence.
How does portland cement differ from concrete?
Portland cement is not a brand name, but the generic term for the type of cement used in virtually all concrete, just as stainless is a type of steel and sterling a type of silver. Therefore, there is no such thing as a cement sidewalk, or a cement mixer; the proper terms are concrete sidewalk and concrete mixer.
What does portland cement do in concrete?
Portland cement is the basic ingredient of concrete. Concrete is formed when portland cement creates a paste with water that binds with sand and rock to harden. Cement is manufactured through a closely controlled chemical combination of calcium, silicon, aluminum, iron and other ingredients.
What is the most commonly used type of concrete pavement?
1. What is the most commonly used type of concrete pavement? Explanation: The most commonly used type is unreinforced, dowels and ties are not considered as reinforcements in slab.
What is portland cement used for?
Basic use. Use Portland Cement in concrete for bridges, walls, culverts, floors, pavements, sidewalks, pipe, railway structures, reinforced concrete buildings, tanks and reservoirs, as well as for masonry units and other precast products.
Why is concrete a bad building material?
The environmental impact of concrete Cement production alone generates around 2.5 billion tonnes of carbon dioxide (CO2) per year—about 8% of the global total. Making cement requires the use of long rotating kilns the length of two football pitches, which are heated to around 1,500°C.
What causes cracking in concrete?
Cracks in concrete are common and they develop when stresses in the concrete exceed its strength. Cracks are often caused by normal shrinkage of the concrete when hardening and drying.
Why is it called portland cement?
The inventor Joseph Aspdin, of England, patented the basic process in 1824, naming it for the resemblance of the cement when set to portland stone, a limestone from the Isle of Portland.
Why are fibres used in Portland cement concrete?
Portland cement concrete is a brittle material. The main reason for incorporating fibres into a cement matrix is to improve the cracking deformation characteristics, increasing not only the toughness, impact and tensile strength, but also eliminating temperature and shrinkage cracks.
Is CAC easier to compact than portland cement?
For a given water/cement and aggregate grading CAC is easier to compact than Portland cement, although before vibration the concrete may appear to have poor workability. Fig. 13.24. Relationship of slump to water/cement ratio. It is frequently noted that CACC should be demoulded as soon as possible and the surface sprayed with water.
What is the pH of Portland cement pore solution?
Portland cement concrete pore solution mainly consists of saturated Ca (OH)2 (pH = 12.6), but the presence of NaOH and KOH increases the pH to more than 13 ( Poursaee, 2010 ). In concrete structures, the steel normally has many years to develop a protective passive film over its surface before chlorides penetrate the concrete cover.
What is the risk of spalling in concrete?
The high risk of spalling of high strength concretes is believed to be due to the reduced permeability and increased brittleness, compared to normal strength concretes. The risk of spalling is further exacerbated when the concretes are exposed to rapid rise of temperatures, such as in hydrocarbon fires.
